Jaguar XJ6 1997 User Manual

3261 Jaguar XJ6

Models covered

Jaguar XJ6 models with 3.2 litre (3239 cc), 3.6 litre (3590 cc) & 4.0 litre (3980 cc) six-cylinder in-line dohc petrol engines and automatic transmission

Covers most features of Daimler 3.6 and 4.0 litre models Does not cover 2.9 litre (2919 cc) sohc engine or manual transmission Does not cover XJR models or revised Jaguar/Daimler model ranges introduced September 1994

Jaguar XJ6

Service and Repair Manual

Mike Stubblefield

A book in the Haynes Service and Repair Manual Series

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage or retrieval system, without permission in writing from the copyright holder.

ISBN 1 85960 261 4

British Library Cataloguing in Publication Data

A catalogue record for this book is available from the British Library.

Printed by J H Haynes & Co. Ltd, Sparkford, Nr Yeovil,

Somerset BA22 7JJ

Haynes Publishing

Sparkford, Nr Yeovil, Somerset BA22 7JJ, England

Haynes North America, Inc

861 Lawrence Drive, Newbury Park, California 91320, USA

Editions Haynes S.A.

147/149, rue Saint Honoré, 75001 PARIS, France

Haynes Publishing Nordiska AB

Fyrisborgsgatan 5, 754 50 Uppsala, Sverige

ABCDE FGHIJ KLMNO PQRST

1 2 3

(3261-248-11AA1)

3261 Jaguar XJ6

LIVING WITH YOUR JAGUAR XJ6

Introduction Page 0•4 Notes for UK readers Page 0•4 Safety first! Page 0•5

Roadside repairs

Introduction Page 0•6 If your car won’t start Page 0•6 Jump starting Page 0•7 Wheel changing Page 0•8 Identifying leaks Page 0•9 Towing Page 0•9

Weekly checks

Introduction Page 0•10 Underbonnet check points Page 0•10 Engine oil level Page 0•11 Coolant level Page 0•11 Brake fluid level Page 0•12 Screen washer fluid level Page 0•12 Power steering fluid level Page 0•13 Wiper blades Page 0•13 Tyre condition and pressure Page 0•14 Battery Page 0•15 Bulbs and fuses Page 0•15

Lubricants, fluids and tyre pressures Page 0•16

MAINTENANCE

Routine maintenance and servicing Page 1•1

Servicing specifications Page 1•2 Maintenance schedule Page 1•3 Maintenance procedures Page 1•6

Contents

3261 Jaguar XJ6

REPAIRS & OVERHAUL

Engine and associated systems

Engine in-car repair procedures Page 2A•1 Engine removal and overhaul procedures Page 2B•1 Cooling, heating and air conditioning systems Page 3•1 Fuel and exhaust systems Page 4•1 Engine electrical systems Page 5•1 Emissions and engine cone control systems Page 6•1

Transmission

Automatic transmission Page 7•1 Drivetrain Page 8•1

Brakes and suspension

Braking system Page 9•1 Suspension and steering systems Page 10•1

Body equipment

Bodywork and fittings Page 11•1 Body electrical systems Page 12•1

Wiring diagrams Page 12•16

REFERENCE

Dimensions and weights Page REF•1 Jacking and vehicle support Page REF•1 Radio/cassette unit anti-theft system - precaution Page REF•1 Conversion factors Page REF•2 Use of English Page REF•3 Buying spare parts and vehicle identification Page REF•4 General repair procedures Page REF•5 Tools and working facilities Page REF•6 MOT test checks Page REF•8 Fault finding Page REF•12 Glossary of technical terms Page REF•18

Index Page REF•22

Contents

These models are equipped with dual overhead cam in-line sixcylinder engines. The engines feature a computer-controlled ignition system and electronic fuel injection. Transmissions are a four-speed automatic equipped with a lock-up torque converter. The transmission is mounted to the back of the engine, and power is transmitted to the fully independent rear axle through a two-piece propshaft. The differential is bolted solidly to a frame crossmember and drives the wheels through driveshafts equipped with inner and outer U-joints.

The front suspension is fitted with upper and lower control arms, coil springs and shock absorbers. The rear suspension is an independent type suspension which also have coil spring/shock absorber assemblies and a lower control arm. The rear driveshaft acts as the upper control arm.

Power-assisted Anti-lock Brake Systems (ABS) with four-wheel disc brakes are standard equipment on all Jaguar XJ6 models covered in this manual. Power rack-and-pinion steering is also standard equipment.

Your Jaguar manual

The aim of this manual is to help you get the best value from your vehicle. It can do so in several ways. It can help you decide what work must be done (even should you choose to get it done by a garage). It will also provide information on routine maintenance and servicing, and give a logical course of action and diagnosis when random faults occur. However, it is hoped that you will use the manual by tackling the work yourself. On simpler jobs it may even be quicker than booking the car into a garage and going there twice, to leave and collect it. Perhaps most important, a lot of money can be saved by avoiding the costs a garage must charge to cover its labour and overheads.

The manual has drawings and descriptions to show the function of the various components so that their layout can be understood. Tasks are described and photographed in a clear step-by-step sequence.

Notes for UK readers

Because this manual was originally written in the US, its layout differs from our UK-originated manuals. The preliminary and reference sections have been re-written specifically for the UK market, and the maintenance schedule has been amended to suit UK vehicles. However, it will be noticed that some references to components

remain in the US style; the UK equivalent of US components and various other US words is given in the Section headed “Use of English”. It should be remembered that the project vehicle used in the main Chapters of this manual was a left-hand drive US model; therefore, the position of the steering wheel, steering column and pedals, etc. will be on the opposite side of the vehicle on UK models. References to “right” and “left” will need to be considered carefully to decide which applies to UK models (eg the headlight dipped beams should be adjusted to dip to the left of the headlight vertical line described in Chapter 12, instead of to the right on US models). In other instances, no reference is made to the location of a particular item, but that item may be located on the opposite side of the vehicle on UK models. Reference to the underbonnet photos at the start of Chapter 1 will give the reader the location of the engine compartment components on UK models.

All specifications in the main Chapters of the manual appear in Imperial form; the equivalent metric values can be calculated using the “Conversion factors” page.

The only other major difference between UK and US models is in the level of emission control equipment fitted to the vehicle. To meet the strict emission standards present in the US, all vehicles for that market are fitted with various emission control systems (see Chapter 6), most of which are not fitted to the corresponding UK model, especially so on early models. Therefore, a lot of the information contained in Chapter 6 is not applicable to UK models.

Acknowledgements

Thanks are due to Jean Preis, Rich Wilson and Ray Marcuse of Silver Star Jaguar (Thousand Oaks, CA), Rick Calaci of Conejo Imports (Newbury Park, CA) and Jim Strohmeier and Jonathan Lund of British Motor Cars (Thousand Oaks, CA), for providing valuable technical information. Technical writers who contributed to this project include Jeff Kibler, Robert Maddox and Jay Storer.

We take great pride in the accuracy of information given in this manual, but vehicle manufacturers make alterations and design changes during the production run of a particular vehicle of which they do not inform us. No liability can be accepted by the authors or publishers for loss, damage or injury caused by any errors in, or omissions from, the information given.

0•4 Introduction

3261 Jaguar XJ6

Haynes mechanic, author and photographer with 1989 Jaguar XJ6

3261 Jaguar XJ6

Safety first! 0•5

Working on your car can be dangerous. This page shows just some of the potential risks and hazards, with the aim of creating a safety-conscious attitude.

General hazards

Scalding

• Don’t remove the radiator or expansion tank cap while the engine is hot.

• Engine oil, automatic transmission fluid or power steering fluid may also be dangerously hot if the engine has recently been running.

Burning

• Beware of burns from the exhaust system and from any part of the engine. Brake discs and drums can also be extremely hot immediately after use.

Crushing

• When working under or near a raised vehicle, always supplement the jack with axle stands, or use drive-on ramps.

Never venture under a car which is only supported by a jack.

• Take care if loosening or tightening hightorque nuts when the vehicle is on stands. Initial loosening and final tightening should be done with the wheels on the ground.

Fire

• Fuel is highly flammable; fuel vapour is explosive.

• Don’t let fuel spill onto a hot engine.

• Do not smoke or allow naked lights (including pilot lights) anywhere near a vehicle being worked on. Also beware of creating sparks (electrically or by use of tools).

• Fuel vapour is heavier than air, so don’t work on the fuel system with the vehicle over an inspection pit.

• Another cause of fire is an electrical overload or short-circuit. Take care when repairing or modifying the vehicle wiring.

• Keep a fire extinguisher handy, of a type suitable for use on fuel and electrical fires.

Electric shock

• Ignition HT voltage can be dangerous, especially to people with heart problems or a pacemaker. Don’t work on or near the ignition system with the engine running or the ignition switched on.

• Mains voltage is also dangerous. Make sure that any mains-operated equipment is correctly earthed. Mains power points should be protected by a residual current device (RCD) circuit breaker.

Fume or gas intoxication

• Exhaust fumes are poisonous; they often contain carbon monoxide, which is rapidly fatal if inhaled. Never run the engine in a confined space such as a garage with the doors shut.

• Fuel vapour is also poisonous, as are the vapours from some cleaning solvents and paint thinners.

Poisonous or irritant substances

• Avoid skin contact with battery acid and with any fuel, fluid or lubricant, especially antifreeze, brake hydraulic fluid and Diesel fuel. Don’t syphon them by mouth. If such a substance is swallowed or gets into the eyes, seek medical advice.

• Prolonged contact with used engine oil can cause skin cancer. Wear gloves or use a barrier cream if necessary. Change out of oilsoaked clothes and do not keep oily rags in your pocket.

• Air conditioning refrigerant forms a poisonous gas if exposed to a naked flame (including a cigarette). It can also cause skin burns on contact.

Asbestos

• Asbestos dust can cause cancer if inhaled or swallowed. Asbestos may be found in gaskets and in brake and clutch linings. When dealing with such components it is safest to assume that they contain asbestos.

Special hazards

Hydrofluoric acid

• This extremely corrosive acid is formed when certain types of synthetic rubber, found in some O-rings, oil seals, fuel hoses etc, are exposed to temperatures above 4000C. The rubber changes into a charred or sticky substance containing the acid. Once formed,

the acid remains dangerous for years. If it gets onto the skin, it may be necessary to amputate the limb concerned.

• When dealing with a vehicle which has suffered a fire, or with components salvaged from such a vehicle, wear protective gloves and discard them after use.

The battery

• Batteries contain sulphuric acid, which attacks clothing, eyes and skin. Take care when topping-up or carrying the battery.

• The hydrogen gas given off by the battery is highly explosive. Never cause a spark or allow a naked light nearby. Be careful when connecting and disconnecting battery chargers or jump leads.

Air bags

• Air bags can cause injury if they go off accidentally. Take care when removing the steering wheel and/or facia. Special storage instructions may apply.

Diesel injection equipment

• Diesel injection pumps supply fuel at very high pressure. Take care when working on the fuel injectors and fuel pipes.

Warning: Never expose the hands, face or any other part of the body

to injector spray; the fuel can penetrate the skin with potentially fatal results.

Remember...

• Do use eye protection when using power tools, and when working under the vehicle.

• Do wear gloves or use barrier cream to protect your hands when necessary.

• Do get someone to check periodically that all is well when working alone on the vehicle.

• Do keep loose clothing and long hair well out of the way of moving mechanical parts.

• Do remove rings, wristwatch etc, before working on the vehicle – especially the electrical system.

• Do ensure that any lifting or jacking equipment has a safe working load rating adequate for the job.

A few tips

DON’T

• Don’t attempt to lift a heavy component which may be beyond your capability – get assistance.

• Don’t rush to finish a job, or take unverified short cuts.

• Don’t use ill-fitting tools which may slip and cause injury.

• Don’t leave tools or parts lying around where someone can trip over them. Mop up oil and fuel spills at once.

• Don’t allow children or pets to play in or near a vehicle being worked on.

3261 Jaguar XJ6

0•6 Roadside repairs

The following pages are intended to help in dealing with common roadside emergencies and breakdowns. You will find more detailed fault finding information at the back of the manual, and repair information in the main chapters.

If your car won’t start and the starter motor doesn’t turn

M If it’s a model with automatic transmission, make sure the

selector is in ‘P’ or ‘N’.

M Open the bonnet and make sure that the battery terminals

are clean and tight.

M Switch on the headlights and try to start the engine. If the

headlights go very dim when you’re trying to start, the battery is probably flat. Get out of trouble by jump starting (see next page) using a friend’s car.

If your car won’t start even though the starter motor turns as normal

M Is there fuel in the tank? M Is there moisture on electrical components under the

bonnet? Switch off the ignition, then wipe off any obvious dampness with a dry cloth. Spray a water-repellent aerosol product (WD-40 or equivalent) on ignition and fuel system electrical connectors like those shown in the photos. Pay special attention to the ignition coil wiring connector and HT leads.

Check the condition and security of the battery connections.

Check that the spark plug HT leads are securely connected by pushing them onto the plugs and distributorery connections.

Check that the HT leads and wiring connectors are securely connected to the ignition coil.

Check that the wiring connectors are securely connected to the injectors and various fuel system sensors and switches.

Check that electrical connections are secure (with the ignition switched off) and spray them with a water dispersant spray like WD40 if you suspect a problem due to damp

3261 Jaguar XJ6

Roadside repairs 0•7

When jump-starting a car using a booster battery, observe the following precautions:

4 Before connecting the booster

battery, make sure that the ignition is switched off.

4 Ensure that all electrical equipment

(lights, heater, wipers, etc) is switched off.

4 Take note of any special precautions

printed on the battery case.

4 Make sure that the booster battery

is the same voltage as the discharged one in the vehicle.

4 If the battery is being jump-started

from the battery in another vehicle, the two vehicles MUST NOT TOUCH each other.

4 Make sure that the transmission is in

neutral (or PARK, in the case of automatic transmission).

Jump starting will get you out of trouble, but you must correct whatever made the battery go flat in the first

place. There are three possibilities:

1) The battery has been drained by repeated attempts to start, or by leaving the lights on.

2) The charging system is not working properly (alternator drivebelt slack or broken, alternator wiring fault or alternator itself faulty).

3) The battery itself is at fault (electrolyte low, or battery worn out).

Connect one end of the red jump lead to the positive (+) terminal of the flat battery

Connect the other end of the red lead to the positive (+) terminal of the booster battery

Connect one end of the black jump lead to the negative (-) terminal of the booster battery

Connect the other end of the black jump lead to a bolt or bracket on the engine block, well away from the battery, on the vehicle to be started

1 2 3

Make sure that the jump leads will not come into contact with the fan, drivebelts or other moving parts of the engine

Start the engine using the booster battery, then with the engine running at idle speed, disconnect the jump leads in the reverse order of connection

Jump starting

3261 Jaguar XJ6

0•8 Roadside repairs

The spare wheel and tools are stored in the boot. Remove the carpet cover then unscrew the retainer and lift out the spare

wheel from the boot.

Wheel changing

Some of the details shown here will vary according to model. For instance, the location of the spare wheel and jack is not the same on all cars. However, the basic principles apply to all vehicles.

Warning: Do not change a wheel in a situation where you risk being hit by other traffic. On busy roads, try to stop in a lay-by or a gateway. Be wary of passing traffic while changing the wheel – it is easy to become distracted by the job in hand.

Finally...

M Remove the wheel chocks. M

Check the tyre pressure on the wheel just fitted. If it is low, or if you don’t have a pressure gauge with you, drive slowly to the nearest garage and inflate the tyre to the right pressure.

M Have the damaged tyre or wheel repaired

as soon as possible.

Remove the plastic cover from the end of the vehicle jack lifting point tube, nearest to the wheel that is being changed.

Slide the lifting bracket of the jack fully into the lifting point tube. Make sure the jack is located on firm ground.

Raise the jack until the wheel is raised clear of the ground. Unscrew the wheel

nuts and remove the wheel. Fit the spare wheel and screw on the nuts. Lightly tighten the nuts then lower the vehicle to the ground.

With the vehicle on the ground, remove

the trim cap (where fitted) and slacken

each wheel nut by half a turn.

Remove the jack and wheelbrace its holder which is located behind the spare wheel.

Securely tighten the wheel nuts in a diagonal sequence then (where necessary)

refit the wheel trim cap. Stow the tolls and punctured wheel and back in the luggage compartment and secure them in position. Note that the wheel nuts should be slackened and retightened to the specified torque at the earliest possible opportunity.

Preparation

M When a puncture occurs, stop as soon as

it is safe to do so.

M Park on firm level ground, if possible,

and well out of the way of other traffic.

M Use hazard warning lights if necessary.

M If you have one, use a warning triangle to

alert other drivers of your presence.

M Apply the handbrake and engage first or

reverse gear (or Park on models with automatic transmission.

M Chock the wheel diagonally opposite the

one being removed – a couple of large stones will do for this.

M If the ground is soft, use a flat piece of

wood to spread the load under the jack.

Changing the wheel

3261 Jaguar XJ6

Roadside repairs 0•9

When all else fails, you may find yourself having to get a tow home – or of course you may be helping somebody else. Long-distance recovery should only be done by a garage or breakdown service. For shorter distances, DIY towing using another car is easy enough, but observe the following points: M Use a proper tow-rope – they are not expensive. The vehicle being towed must display an ‘ON TOW’ sign in its rear window. M Always turn the ignition key to the ‘on’ position when the vehicle is being towed, so that the steering lock is released, and that the direction indicator and brake lights will work. M Only attach the tow-rope to the towing eyes provided. On some models with energyabsorbing bumpers there are no front towing eyes; on these vehicles the tow-rope should

be attached around the rear arm of the lower control arm so that the rope passes on the inside of the coil spring. M Before being towed, release the handbrake and select neutral on the transmission. M Note that greater-than-usual pedal pressure will be required to operate the brakes, since the vacuum servo unit is only operational with the engine running. M On models with power steering, greaterthan-usual steering effort will also be required. M The driver of the car being towed must keep the tow-rope taut at all times to avoid snatching. M Make sure that both drivers know the route before setting off. M Only drive at moderate speeds and keep the distance towed to a minimum. Drive

smoothly and allow plenty of time for slowing down at junctions. M On models with automatic transmission, special precautions apply. If in doubt, do not tow, or transmission damage may result.

Caution: On models with automatic transmission, if the vehicle is to be towed with its rear wheels on the ground, and extra 1.7 litres of fluid should be added to the transmission, prior to towing (this extra fluid must be drained before driving the vehicle). Even with the extra fluid added to the transmission, do not tow the vehicle at speeds in excess of 30 mph (50 kmh) or for a distance of greater than 15 miles (25 km). If towing speed/distance are to exceed these limits, then the vehicle must be towed with its rear wheels off the ground.

Towing

Puddles on the garage floor or drive, or obvious wetness under the bonnet or underneath the car, suggest a leak that needs investigating. It can sometimes be difficult to decide where the leak is coming from, especially if the engine bay is very dirty already. Leaking oil or fluid can also be blown rearwards by the passage of air under the car, giving a false impression of where the problem lies.

Warning: Most automotive oils and fluids are poisonous. Wash them off skin, and change out of contaminated clothing, without delay.

The smell of a fluid leaking from the car may provide a clue to what’s leaking. Some

fluids are distinctively coloured. It may help to clean the car and to park it over some clean paper as an aid to locating the source of the leak.

Remember that some leaks may only occur while the engine is running.

Sump oil Gearbox oil

Brake fluid

Power steering fluid

Oil from filter

Antifreeze

Engine oil may leak from the drain plug... ...or from the base of the oil filter.

Leaking antifreeze often leaves a crystalline deposit like this.

Gearbox oil can leak from the seals at the inboard ends of the driveshafts.

A leak occurring at a wheel is almost certainly brake fluid.

Power steering fluid may leak from the pipe connectors on the steering rack.

3261 Jaguar XJ6

0•10 Weekly checks

There are some very simple checks which need only take a few minutes to carry out, but which could save you a lot of inconvenience and expense.

These "Weekly checks" require no great skill or special tools, and the small amount of time they take to perform could prove to be very well spent, for example;

M Keeping an eye on tyre condition and pressures, will not only help to stop them wearing out prematurely, but could also save your life.

Many breakdowns are caused by electrical problems. Battery-related faults are particularly common, and a quick check on a regular basis will often prevent the majority of

these.

M If your car develops a brake fluid leak, the first time you might know about it is when your brakes don't work properly. Checking the level regularly will give advance warning of this kind of problem.

M If the oil or coolant levels run low, the cost of repairing any engine damage will be far greater than fixing the leak, for example.

Introduction

3.6 litre engine (others similar)

Viewed from right-hand side

Engine oil level dipstick

Engine oil filler cap

Coolant expansion tank

Brake fluid reservoir

Screen washer fluid reservoir

Battery

Power steering fluid reservoir

Underbonnet check points

3261 Jaguar XJ6

Weekly checks 0•11

Engine oil level

Before you start

4 Make sure that your car is on level ground. 4 Check the oil level before the car is driven,

or at least 5 minutes after the engine has been switched off.

The correct oil

Modern engines place great demands on their oil. It is very important that the correct oil for your car is used (See “Lubricants, fluids and tyre pressures”).

Car care

l If you have to add oil frequently, you should check whether you have any oil leaks. Place some clean paper under the car overnight, and check for stains in the morning. If there are no leaks, the engine may be burning oil

(see “Fault finding”).

l Always maintain the level between the upper and lower dipstick marks (see photo 3). If the level is too low severe engine damage may occur. Oil seal failure may result if the engine is overfilled by adding too much oil.

If the oil level is checked immediately after driving the vehicle, some of the oil will

remain in the upper engine components, resulting in an inaccurate reading on the dipstick!

The dipstick is located at the rear of the engine on the left-hand side (see “Underbonnet check points” on page 0•10 for exact location). Withdraw the dipstick.

Using a clean rag or paper towel remove all oil from the dipstick. Insert the clean dipstick into the tube as far as it will go, then withdraw it again.

Note the oil level on the end of the dipstick which should be between the

upper and lower marks. The “M” mark is for use when checking the oil level after the vehicle has been standing overnight; in this case the oil level should be between the “M” and upper level markings.

Oil is added through the filler cap. Unscrew the cap and top-up the level; a

funnel may help to reduce spillage. Add the oil slowly, checking the level on the dipstick often. Don’t overfill (see “Car care” left).

Warning: DO NOT attempt to remove the expansion tank pressure cap when the engine is hot, as there is a very great risk of scalding. Do not leave open containers of coolant about, as it is poisonous.

Car care

l Adding coolant should not be necessary on a regular basis. If frequent topping-up is required, it is likely there is a leak. Check the radiator, all hoses and joint faces for signs of staining or wetness, and rectify as necessary. l It is important that antifreeze is used in the cooling system all year round, not just during the winter months. Don’t top-up with water alone, as the antifreeze will become too diluted.

Coolant level

The coolant level should be checked only with the engine cold. The level is checked

in the expansion tank on the left-hand side of the engine compartment. Remove the expansion tank pressure cap and check that the coolant level is upto the base of filler neck.

If topping up is necessary, add a mixture of water and antifreeze to the expansion tank until the coolant level is upto the

base of the filler neck. Once the level is correct, securely refit the pressure cap.

3261 Jaguar XJ6

0•12 Weekly checks

Brake fluid level

Warning: l Brake fluid can harm your eyes and will damage painted surfaces, so use extreme caution when handling and pouring it. l Do not use fluid that has been standing open for some time, as it absorbs moisture from the air, which can cause a dangerous loss of braking effectiveness.

Safety first!

l If the reservoir requires repeated toppingup this is an indication of a fluid leak somewhere in the system, which should be investigated immediately.

l If a leak is suspected, the car should not be driven until the braking system has been checked. Never take any risks where brakes are concerned.

• Make sure that your car is on level ground.

• The fluid level in the

reservoir will drop slightly as the brake pads wear down, but the fluid level must never be allowed to drop below the “MIN” mark.

The brake fluid reservoir is located on the right-hand rear corner of the engine compartment, on top of the master cylinder.

The upper (MAX) and lower (MIN) fluid level markings are on the side of the brake fluid reservoir. The fluid level must always be kept between these two marks.

If topping up is necessary, first wipe clean the area around the filler cap with a clean cloth then unscrew the cap and position it clear of the reservoir.

Carefully add fluid, avoiding spilling it on the surrounding paintwork. Use only the

specified hydraulic fluid. After filling the correct level, refit the cap and tighten it securely. Wipe off any spilt fluid.

Screenwash additives not only keep the winscreen clean during foul weather, they also prevent the washer system freezing in cold weather - which is when you are likely to need it most. Don’t top up using plain water as the screenwash will become too diluted, and will freeze during cold weather. On no account use

coolant antifreeze in the washer system this could discolour or damage paintwork.

Screen washer fluid level

If topping up is necessary, add water and

a screenwash additive in the quantities

recommended on the bottle.

The screen washer fluid reservoir is located in the front, right-hand corner of the engine compartment. The level is visible through the reservoir body.

3261 Jaguar XJ6

Weekly checks 0•13

Power steering fluid level

Before you start:

4 Park the vehicle on level ground. 4 Set the steering wheel straight-ahead. 4 The engine should be turned off.

Safety first!

l The need for frequent topping-up indicates a leak, which should be investigated immediately.

For the check to be accurate, the steering must not be turned once the engine has been stopped.

Wipe clean the area around the reservoir cap then remove the cap noting that it unscrews in a clockwise direction (see arrow on cap).

Wipe clean the cap dipstick then insert it fully into the reservoir and withdraw it.

Note the fluid level on the end of the dipstick. If the fluid is cold (vehicle not

having been used) the fluid level should be upto the COLD level marking (1). If the vehicle has been driven and the fluid is hot then the fluid level should be upto the upper (HOT) level marking (2).

If necessary, top-up the reservoir with the specified type of fluid (note that the type

of fluid differs according to model - see “Lubricants, fluids and tyre pressures” on page 0•16). Once the level is correct, securely refit the reservoir cap. Do not overfill the reservoir.

Wiper blades

Check the condition of the wiper blades: if they are cracked or show signs of

deterioration, or if the glass swept area is smeared, renew them. For maximum clarity of vision, wiper blades should be renewed annually.

To remove a wiper blade, pull the arm fully away from the screen until it locks.

Swivel the blade then depress the locking clip at the base of the mounting block and slide the blade off the arm.

Warning: l This check applies only to vehicles fitted with a separate power steering system. For vehicles fitted with power

steering where the fluid reservoir is part of the power hydraulic system, this weekly check is not applicable. l It is essential to use the correct power steering fluid, this being dependent on the year of manufacture and type of system fitted. A label attached to the fluid reservoir will indicate the specification of fluid. However, if necessary refer to the driver’s handbook supplied with the vehicle or to your local Jaguar dealer.

3261 Jaguar XJ6

0•14 Weekly checks

Tyre condition and pressure

It is very important that tyres are in good condition, and at the correct pressure - having a tyre failure at any speed is highly dangerous. Tyre wear is influenced by driving style - harsh braking and acceleration, or fast cornering, will all produce more rapid tyre wear. As a general rule, the front tyres wear out faster than the rears. Interchanging the tyres from front to rear ("rotating" the tyres) may result in more even wear. However, if this is completely effective, you may have the expense of replacing all four tyres at once! Remove any nails or stones embedded in the tread before they penetrate the tyre to cause deflation. If removal of a nail does reveal that

the tyre has been punctured, refit the nail so that its point of penetration is marked. Then immediately change the wheel, and have the tyre repaired by a tyre dealer. Regularly check the tyres for damage in the form of cuts or bulges, especially in the sidewalls. Periodically remove the wheels, and clean any dirt or mud from the inside and outside surfaces. Examine the wheel rims for signs of rusting, corrosion or other damage. Light alloy wheels are easily damaged by "kerbing" whilst parking; steel wheels may also become dented or buckled. A new wheel is very often the only way to overcome severe damage.

New tyres should be balanced when they are fitted, but it may become necessary to rebalance them as they wear, or if the balance weights fitted to the wheel rim should fall off. Unbalanced tyres will wear more quickly, as will the steering and suspension components. Wheel imbalance is normally signified by vibration, particularly at a certain speed (typically around 50 mph). If this vibration is felt only through the steering, then it is likely that just the front wheels need balancing. If, however, the vibration is felt through the whole car, the rear wheels could be out of balance. Wheel balancing should be carried out by a tyre dealer or garage.

Tread Depth - visual check

The original tyres have tread wear safety bands (B), which will appear when the tread depth reaches approximately 1.6 mm. The band positions are indicated by a triangular mark on the tyre sidewall (A).

Tread Depth - manual check

Alternatively, tread wear can be monitored with a simple, inexpensive device known as a tread depth indicator gauge.

Tyre Pressure Check

Check the tyre pressures regularly with the tyres cold. Do not adjust the tyre pressures immediately after the vehicle has been used, or an inaccurate setting will result.

Tyre tread wear patterns

Shoulder Wear

Underinflation (wear on both sides)

Under-inflation will cause overheating of the tyre, because the tyre will flex too much, and the tread will not sit correctly on the road surface. This will cause a loss of grip and excessive wear, not to mention the danger of sudden tyre failure due to heat build-up. Check and adjust pressures

Incorrect wheel camber (wear on one side)

Repair or renew suspension parts

Hard cornering

Reduce speed!

Centre Wear

Overinflation

Over-inflation will cause rapid wear of the centre part of the tyre tread, coupled with reduced grip, harsher ride, and the danger of shock damage occurring in the tyre casing.

Check and adjust pressures

If you sometimes have to inflate your car’s tyres to the higher pressures specified for maximum load or sustained high speed, don’t forget to reduce the pressures to normal afterwards.

Uneven Wear

Front tyres may wear unevenly as a result of wheel misalignment. Most tyre dealers and garages can check and adjust the wheel alignment (or "tracking") for a modest charge.

Incorrect camber or castor

Repair or renew suspension parts

Malfunctioning suspension

Repair or renew suspension parts

Unbalanced wheel

Balance tyres

Incorrect toe setting

Adjust front wheel alignment Note: The feathered edge of the tread which typifies toe wear is best checked by feel.

3261 Jaguar XJ6

Weekly checks 0•15

Battery

Caution: Before carrying out any work on the vehicle battery, read the precautions given in "Safety first" at the start of this manual.

4 Make sure that the battery tray is in good condition, and that the clamp is tight. Corrosion on the tray, retaining clamp and the battery itself can be removed with a solution of water and baking soda. Thoroughly rinse all cleaned areas with water. Any metal parts damaged by corrosion should be covered with a zinc-based primer, then painted. 4 Periodically (approximately every three months), check the charge condition of the battery as described in Chapter 5. 4 If the battery is flat, and you need to jump start your vehicle, see Roadside Repairs.

The battery is located in the left-hand, rear corner of the engine compartment.

Check the battery terminals for signs of corrosion and examine the battery leads closely for signs of damage.

Check the battery lead clamps for tightness to ensure good electrical connections.

Battery corrosion can be kept to a minimum by applying a layer of petroleum jelly to the clamps and terminals after they are reconnected.

If corrosion (white, fluffy deposits) is

evident, remove the cables from the

battery terminals, clean them with a small wire brush, then refit them. Automotive stores sell a tool for cleaning the battery post . . .

. . . as well as the battery cable clamps

Bulbs and fuses

4 Check all external lights and the horn. Refer to the appropriate Sections of Chapter 12 for details if any of the circuits are found to be inoperative.

4 Visually check all accessible wiring connectors, harnesses and retaining clips for security, and for signs of chafing or damage.

If you need to check your brake lights and indicators unaided, back up to a wall or

garage door and operate the lights. The reflected light should show if they are working properly.

If a single indicator light, stop light or headlight has failed, it is likely that a bulb

has blown and will need to be replaced. Refer to Chapter 12 for details. If both stop lights have failed, it is possible that the switch has failed (see Chapter 9).

If more than one indicator light or tail light has failed it is likely that either a fuse has

blown or that there is a fault in the circuit. The fuseboxes are located behind the left and right side kick panels and in the centre console glove box (see Chapter 12).

To replace a blown fuse, simply pull it out and fit a new fuse of the correct rating

(see Chapter 12). If the fuse blows again, it is important that you find out why - a complete checking procedure is given in Chapter 12.

0•16 Lubricants, fluids and tyre pressures

3261 Jaguar XJ6

Lubricants and fluids

Engine . . . . . . . . . . . . . . . . . . . . . . . . . . Multigrade engine oil to API SG or higher (Duckhams QS, QXR, Hypergrade Plus,

Hypergrade, or 10W-40 Motor Oil)

Cooling system . . . . . . . . . . . . . . . . . . . Ethylene glycol based (phosphate free) antifreeze

(Duckhams Antifreeze and Summer Coolant)

Automatic transmission . . . . . . . . . . . . Dexron type II automatic transmission fluid (ATF) (Duckhams Uni-Matic)

Differential:

Standard differential . . . . . . . . . . . . . . SAE EP90 to API GL5 (Duckhams 80W-90S Gear Oil)

Powr-lok differential . . . . . . . . . . . . . . . SAE 90 to API GL5 (Duckhams Hypoid 90 DL)

Braking system . . . . . . . . . . . . . . . . . . . Hydraulic fluid to DOT 4 (Duckhams Universal Brake and Clutch Fluid)

Power steering (with separate reservoir) . dependent on year of manufacture and system fitted - refer to your Jaguar dealer

Power hydraulic system . . . . . . . . . . . . . Castrol or Jaguar hydraulic system mineral oil (HSMO) Refer to your Jaguar dealer

Tyre pressures

Note: Tyre pressures must always be checked with the tyres cold to ensure accuracy.

Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 psi (2.3 bar)

Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 psi (2.3 bar)

Note: Jaguar state that the tyre pressures maybe reduced by up to 8 psi (0.6 bar) on the front tyres and 6 psi (0.4 bar) on the rear

tyres to increase the ride comfort. This is only allowable if the vehicle is not to be driven at speeds in excess of 100 mph (160 kmh); if speeds are to exceed this, the tyres must be run at the specified pressures.

Oils perform vital tasks in all engines. The higher the engine’s performance, the greater the demand on lubricants to minimise wear as well as optimise power and economy. Duckhams tailors lubricants to the highest technical standards, meeting and exceeding the demands of all modern engines.

HOW ENGINE OIL WORKS

• Beating friction

Without oil, the surfaces inside your engine which rub together will heat, fuse and quickly cause engine seizure. Oil, and its special additives, forms a molecular barrier between moving parts, to stop wear and minimise heat build-up.

• Cooling hot spots

Oil cools parts that the engine’s water-based coolant cannot reach, bathing the combustion chamber and pistons, where temperatures may exceed 1000°C. The oil assists in

transferring the heat to the engine cooling system. Heat in the oil is also lost by air flow over the sump, and via any auxiliary oil cooler.

• Cleaning the inner engine

Oil washes away combustion by-products (mainly carbon) on pistons and cylinders, transporting them to the oil filter, and holding the smallest particles in suspension until they are flushed out by an oil change. Duckhams oils undergo extensive tests in the laboratory, and on the road.

Engine oil types

Mineral oils are the “traditional” oils, generally suited to older engines and cars not used in harsh conditions. Duckhams Hypergrade Plus and Hypergrade are well suited for use in most popular family cars. Diesel oils such as Duckhams Diesel are specially formulated for Diesel engines, including turbocharged models and 4x4s. Synthetic oils are the state-of-the-art in lubricants, offering ultimate protection, but at a fairly high price. One such is Duckhams QS, for use in ultra-high performance engines. Semi-synthetic oils offer high performance engine protection, but at less cost than full synthetic oils. Duckhams QXR is an ideal choice for hot hatches and hard-driven cars.

For help with technical queries on lubricants, call Duckhams Oils on 0181 290 8207

Choosing your engine oil

Note: It is antisocial and illegal to dump oil down the drain. To find the location of your local oil recycling bank, call this number free.

3261 Jaguar XJ6

Chapter 1

Routine maintenance and servicing

Air cleaner element renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Automatic transmission fluid and filter renewal . . . . . . . . . . . . . . . . . 26

Automatic transmission fluid level check . . . . . . . . . . . . . . . . . . . . . 8

Battery check and general information . . . . . . . . . . . . . . . . . . . . . . . 6

Brake fluid renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Braking system - general check and adjustment . . . . . . . . . . . . . . . 11

Coolant renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Crankcase ventilation system check . . . . . . . . . . . . . . . . . . . . . . . . . 20

Differential oil level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Differential oil renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Drivebelt check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Engine oil and filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Front wheel alignment check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Front wheel bearing check and adjustment . . . . . . . . . . . . . . . . . . . 22

Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

General lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Handbrake shoes check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Headlight beam check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Hose and fluid leak check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Ignition system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Intensive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Power hydraulic system fluid level check . . . . . . . . . . . . . . . . . . . . . 5

Propshaft check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Road test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Seat belt check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Spark plug check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Spark plug renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Steering and suspension check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1•1

Contents

Easy, suitable for

novice with little experience

Fairly easy, suitable for beginner with some experience

Fairly difficult,

suitable for competent DIY mechanic

Difficult, suitable for experienced DIY mechanic

Very difficult,

suitable for expert DIY or professional

Degrees of difficulty

Lubricants and fluids

Refer to “Weekly checks”

Capacities

Engine oil

Including oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0 litres

Cooling system

All models (approximate):

From dry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.8 litres

Drain and refill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 litres

Transmission

Automatic transmission (approximate):

From dry:

3.2 litre model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 litres

3.6 and 4.0 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0 litres

Drain and refill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 litres

Differential

All models (approximate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 litres

Cooling system

Antifreeze mixture:

50% antifreeze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Protection down to -37°C (5°F)

55% antifreeze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Protection down to -45°C (-22°F)

Note: Refer to antifreeze manufacturer for latest recommendations.

Ignition system

Spark plugs:

Type:

3.2 litre model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RC12YCC

3.6 and 4.0 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RC9YCC

Electrode gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 mm

*The spark plug gap quoted is that recommended by Champion for their specified plug listed above. If spark plugs of any other type are to be fitted, refer to their manufacturer’s recommendations.

Engine firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5-3-6-2-4

Distributor rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clockwise

Ignition timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 5

Brakes

Disc brake pad friction material minimum thickness:

Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 mm

Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 mm

Handbrake shoe friction material minimum thickness . . . . . . . . . . . . . . 1.5 mm

Handbrake adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 to 5 clicks

Torque wrench settings Nm lbf ft

Automatic transmission sump pan bolts . . . . . . . . . . . . . . . . . . . . . . . . 8 6

Automatic transmission dipstick tube nut . . . . . . . . . . . . . . . . . . . . . . . 20 15

Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 28 17 to 21

Wheel nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 75

1•2 Servicing specifications

3261 Jaguar XJ6

Cylinder location and distributor rotation

The maintenance intervals in this manual are provided with the assumption that you, not the dealer, will be carrying out the work. These are the minimum maintenance intervals recommended by us for vehicles driven daily. If you wish to keep your vehicle in peak condition at all times, you may wish to perform some of these procedures more

often. We encourage frequent maintenance, because it enhances the efficiency, performance and resale value of your vehicle.

When the vehicle is new, it should be serviced by a factoryauthorised dealer service department, in order to preserve the factory warranty.

Maintenance schedule 1•3

3261 Jaguar XJ6

Weekly, or every 250 miles (400 km)

mm Carry out all the operations given in “Weekly

checks” at the start of this manual.

mm Renew the fuel filter (Section 18) mm Check the ignition system components (Section 19) mm Check the crankcase ventilation system

(Section 20)

mm Check the condition and tension of the drivebelt(s)

(Section 21)

mm Check the front wheel bearing adjustment and

repack with grease (Section 22)

mm Check the propshaft fasteners are tightened to the

specified torque (Section 23)

mm Check the front wheel alignment (Section 24) mm Check the headlight beam alignment (Section 25)

Every 7500 miles (12 000 km) or 6 months, whichever comes first

In addition to the operations listed previously, carry out the following:

mm Renew the engine oil and filter (Section 3) mm Check the spark plugs (Section 4) mm Check the power hydraulics fluid level (Section 5) mm Check the battery (Section 6) mm Check all pipes and hoses for signs of damage or

leakage (Section 7)

mm Check the automatic transmission fluid level

(Section 8)

mm Check the differential oil level (Section 9) mm Check the condition of the exhaust system

(Section 10)

mm Check the brake pads and discs for wear and

adjust the handbrake (Section 11)

mm Check the steering and suspension components

for wear or damage and check the wheel nuts are tightened to the correct torque (Section 12)

mm Check the condition of the seat belts (Section 13) mm Lubricate all locks and hinges, and exposed cables

(Section 14)

mm Carry out a road test (Section 15)

Every 2 years, regardless of mileage

mm Renew the coolant (Section 30)

Every 60 000 miles (96 000 km)

In addition to the operations listed previously, carry out the following:

mm Check the handbrake shoes for wear (Section 29)

Every 30 000 miles (48 000 km) or 2 years, whichever comes first

In addition to the operations listed previously, carry out the following:

mm Renew the automatic transmission fluid and filter

(Section 26)

mm Renew the differential oil (Section 27) mm Renew the brake fluid (Section 28)

Every 15 000 miles (24 000 km) or 12 months, whichever comes first

In addition to the operations listed previously, carry out the following:

mm Renew the spark plugs (Section 16) mm Renew the air cleaner element (Section 17)

1•4 Maintenance - component location

3261 Jaguar XJ6

1 Battery 2 Oil filler cap 3 Engine oil dipstick (not visible) 4 Automatic transmission

dipstick (not visible) 5 Brake fluid reservoir 6 Coolant reservoir

(expansion tank) 7 Air cleaner housing 8 Upper radiator hose 9 Spark plugs 10 Distributor 11 Windscreen washer fluid

reservoir 12 Power hydraulic system fluid

reservoir 13 Power steering fluid reservoir

Underbonnet view from the left-hand side of the vehicle

Underbonnet view from the right-hand side of the vehicle

1 Battery 2 Oil filler cap 3 Engine oil dipstick (not visible) 4 Automatic transmission

dipstick (not visible) 5 Brake fluid reservoir 6 Coolant reservoir (expansion

tank) 7 Air cleaner housing 8 Upper radiator hose 9 Spark plugs 10 Distributor 11 Windscreen washer fluid

reservoir 12 Power hydraulic system fluid

reservoir 13 Power steering fluid reservoir

Maintenance - component location 1•5

3261 Jaguar XJ6

Front underbody view

1 Air conditioning compressor 2 Drivebelts 3 Anti-roll bar 4 Alternator 5 Lower radiator hose 6 Lower control arm 7 Steering gear boot 8 Steering gear 9 Engine sump drain plug 10 Exhaust system 11 Outer tie-rod end

Rear underbody view (typical)

1 Rear suspension control arms 2 Differential drain plug 3 Differential filler plug

(not visible) 4 Exhaust pipe 5 Driveshaft 6 Silencers 7 Handbrake cable 8 Fuel filter

1 General information

1 This Chapter is designed to help the home

mechanic maintain his/her vehicle for safety, economy, long life and peak performance. 2 The Chapter contains a master maintenance schedule, followed by Sections dealing specifically with each task in the schedule. Visual checks, adjustments, component renewal and other helpful items are included. Refer to the accompanying illustrations of the engine compartment and the underside of the vehicle for the locations of the various components. 3 Servicing your vehicle in accordance with the mileage/time maintenance schedule and the following Sections will provide a planned maintenance programme, which should result in a long and reliable service life. This is a comprehensive plan, so maintaining some items but not others at the specified service intervals, will not produce the same results. 4 As you service your vehicle, you will discover that many of the procedures can and should - be grouped together, because of the particular procedure being performed, or because of the proximity of two otherwiseunrelated components to one another. For example, if the vehicle is raised for any reason, the exhaust can be inspected at the same time as the suspension and steering components. 5 The first step in this maintenance programme is to prepare yourself before the actual work begins. Read through all the

Sections relevant to the work to be carried out, then make a list and gather all the parts and tools required. If a problem is encountered, seek advice from a parts specialist, or a dealer service department.

2 Intensive maintenance

1 If, from the time the vehicle is new, the

routine maintenance schedule is followed closely, and frequent checks are made of fluid levels and high-wear items, as suggested throughout this manual, the engine will be kept in relatively good running condition, and the need for additional work will be minimised. 2 It is possible that there will be times when the engine is running poorly due to the lack of regular maintenance. This is even more likely if a used vehicle, which has not received regular and frequent maintenance checks, is purchased. In such cases, additional work may need to be carried out, outside of the regular maintenance intervals. 3 If engine wear is suspected, a compression test (refer to Chapter 2) will provide valuable information regarding the overall performance of the main internal components. Such a test can be used as a basis to decide on the extent of the work to be carried out. If, for example, a compression test indicates serious internal engine wear, conventional maintenance as described in this Chapter will not greatly improve the performance of the engine, and may prove a waste of time and money, unless extensive overhaul work is carried out first.

4 The following series of operations are those which are most often required to improve the performance of a generally poor-running engine:

Primary operations

a) Clean, inspect and test the battery

(Section 6).

b) Check all the engine-related fluids (refer

to “Weekly checks”).

c) Check the condition and tension of the

auxiliary drivebelt (Section 21). d) Renew the spark plugs (Section 16). e) Inspect the distributor cap and rotor arm

(Section 19). f) Check the condition of the air filter, and

renew if necessary (Section 17). g) Renew the fuel filter (Section 18). h) Check the condition of all hoses, and

check for fluid leaks (Section 7). i) Check the exhaust gas emissions (see

Chapter 6).

5 If the above operations do not prove fully effective, carry out the following secondary operations:

Secondary operations

All items listed under “Primary operations”,

plus the following:

a) Check the charging system (refer to

Chapter 5). b) Check the ignition system (refer to

Chapter 5). c) Check the fuel system (refer to Chapter 4). d) Renew the distributor cap and rotor arm

(Section 19). e) Renew the ignition HT leads (Section 19).

1•6 Maintenance procedures

3261 Jaguar XJ6

Every 7500 miles (12 000 km) or 6 months

3 Engine oil and filter renewal

1 Frequent oil changes are the best preventive maintenance the home mechanic can give the engine, because ageing oil becomes diluted and contaminated, which leads to premature engine wear. 2 Make sure that you have all the necessary tools before you begin this procedure (see illustration). You should also have plenty of rags or newspapers handy for mopping up any spills. 3 Access to the underside of the vehicle is greatly improved if the vehicle can be lifted on a hoist, driven onto ramps or supported by axle stands. 4 If this is your first oil change, get under the vehicle and familiarise yourself with the location of the oil drain plug. The engine and

3.2 These tools are required when changing the engine oil and filter

1 Drain pan - It should be fairly shallow in

depth, but wide in order to prevent spills

2 Rubber gloves - When removing the drain

plug and filter, it is inevitable that you will get oil on your hands (the gloves will prevent burns)

3 Breaker bar - Sometimes the oil drain plug

is pretty tight and a long breaker bar is needed to loosen it

4 Socket – To be used with the breaker bar

or a ratchet (must be the correct size to fit the drain plug)

5 Filter wrench - This is a metal band-type

wrench, which requires clearance around the filter to be effective

6 Filter wrench - This type fits on the bottom

of the filter and can be turned with a ratchet or breaker bar (different size spanners are available for different types of filters)

exhaust components will be warm during the actual work, so try to anticipate any potential problems before the engine and accessories are hot. 5 Park the vehicle on a level spot. Start the engine and allow it to reach its normal operating temperature (the needle on the temperature gauge should be at least above the bottom mark). Warm oil and contaminates will flow out more easily. Turn off the engine when it’s warmed up. Remove the oil filler cap located next to the valve cover. 6 Raise the vehicle and support it on axle stands.

Warning: To avoid personal injury, never get beneath the vehicle when it is supported by

only by a jack. The jack provided with your vehicle is designed solely for raising the vehicle to remove and replace the wheels. Always use axle stands to support the vehicle when it becomes necessary to place your body underneath the vehicle.

7 Being careful not to touch the hot exhaust components, place the drain pan under the drain plug in the bottom of the pan and remove the plug (see illustration). You may want to wear gloves while unscrewing the plug the final few turns if the engine is really hot. 8 Allow the old oil to drain into the pan. It may be necessary to move the pan farther under the engine as the oil flow slows to a trickle. Inspect the old oil for the presence of metal shavings and chips. 9 After all the oil has drained, wipe off the drain plug with a clean rag. Even minute metal particles clinging to the plug would immediately contaminate the new oil. 10 Clean the area around the drain plug opening, refit the plug and tighten it securely, but do not strip the threads. 11 Move the drain pan into position under the oil filter. 12 Remove all tools, rags, etc. from under the vehicle, being careful not to spill the oil in the drain pan, then lower the vehicle. 13 Loosen the oil filter (see illustration) by turning it anti-clockwise with the filter wrench. Any standard filter wrench should work. Once

the filter is loose, use your hands to unscrew it from the block. Just as the filter comes away from the block, immediately tilt the open end up to prevent the oil inside the filter from spilling out.

Warning: The engine exhaust pipes may still be hot, so be careful.

14 With a clean rag, wipe off the mounting surface on the block. If a residue of old oil is allowed to remain, it will smoke when the block is heated up. It will also prevent the new filter from seating properly. Also make sure that the none of the old gasket remains stuck to the mounting surface. It can be removed with a scraper if necessary. 15 Compare the old filter with the new one to make sure they are the same type. Smear some engine oil on the rubber gasket of the new filter and screw it into place (see illustration). Because over-tightening the filter will damage the gasket, do not use a filter wrench to tighten the filter. Tighten it by hand until the gasket contacts the seating surface. Then seat the filter by giving it an additional 3/4-turn. 16 Add new oil to the engine through the oil filler cap next to the valve cover. Use a spout or funnel to prevent oil from spilling onto the top of the engine. Pour three litres of fresh oil into the engine. Wait a few minutes to allow the oil to drain into the pan, then check the level on the oil dipstick (see “Weekly checks”). If the oil level is at or near the H mark, refit the filler cap hand tight, start the engine and allow the new oil to circulate. 17 Allow the engine to run for about a minute. While the engine is running, look under the vehicle and check for leaks at the sump drain plug and around the oil filter. If either is

leaking, stop the engine and tighten the plug or filter slightly. 18 Wait a few minutes to allow the oil to trickle down into the pan, then recheck the level on the dipstick and, if necessary, add enough oil to bring the level to the H mark. 19 During the first few trips after an oil change, make it a point to check frequently for leaks and proper oil level. 20 The old oil drained from the engine cannot be reused in its present state and should be disposed of. Check with your local authority, or with a local garage to see whether they will accept the oil for recycling. Don’t pour used oil into drains or onto the ground. After the oil has cooled, it can be drained into a suitable container (capped plastic jugs, topped bottles, etc.) for transport to an approved disposal site.

4 Spark plug check

1 Spark plug renewal requires a spark plug socket which fits onto a ratchet spanner. This socket is lined with a rubber grommet to protect the porcelain insulator of the spark plug and to hold the plug while you insert it into the spark plug hole. You will also need a wire-type feeler gauge to check and adjust the spark plug gap and a torque wrench to tighten the new plugs to the specified torque

(see illustration). 2 If you are replacing the plugs, purchase the

new plugs, adjust them to the proper gap and then replace each plug one at a time. Note:

When buying new spark plugs, it’s essential that you obtain the correct plugs for your specific vehicle. This information can be found in the Specifications Section at the beginning of this Chapter, on the Vehicle Emissions Control Information (VECI) label located on the underside of the bonnet (where fitted)or in the owner’s manual. If these sources specify different plugs, purchase the spark plug type specified on the VECI label because that information is provided specifically for your engine.

Every 7500 miles or 6 months 1•7

3.7 The oil drain plug (arrowed) is located at the rear of the sump - use a ring

spanner or socket to remove it

3.13 The oil filter is located on the left side of the engine - use a filter wrench for

removal (tighten the new filter by hand)

3.15 Lubricate the oil filter gasket with

clean engine oil before refitting the filter

3261 Jaguar XJ6

Note: It is antisocial and illegal to dump oil down the drain. To find the location of your local oil recycling bank, call this number free.

3 Inspect each of the new plugs for defects. If there are any signs of cracks in the porcelain insulator of a plug, don’t use it. 4 Check the electrode gaps of the new plugs. Check the gap by inserting the wire gauge of the proper thickness between the electrodes at the tip of the plug (see illustration). The gap between the electrodes should be identical to that listed in this Chapter’s Specifications or on the VECI label (as applicable). If the gap is incorrect, use the notched adjuster on the feeler gauge body to bend the curved side electrode slightly (see

illustration). 5 If the side electrode is not exactly over the

centre electrode, use the notched adjuster to align them.

Caution: If the gap of a new plug must be adjusted, bend only the base of the earth electrode - do not touch the tip.

Removal

6 To prevent the possibility of mixing up spark plug leads, work on one spark plug at a time. Remove the lead and boot from one spark plug. Grasp the boot - not the lead - as shown, give it a half twisting motion and pull straight up (see illustration). 7 If compressed air is available, blow any dirt or foreign material away from the spark plug area before proceeding (a common bicycle pump will also work).

8 Remove the spark plug (see illustration).

9 Whether you are replacing the plugs at this

time or intend to re-use the old plugs, compare each old spark plug with the chart shown on the inside back cover of this manual to determine the overall running condition of the engine.

Refitting

10 Prior to refitting, apply a coat of anti-seize compound to the plug threads (see illustration). It’s often difficult to insert spark plugs into their holes without cross-threading them. To avoid this possibility, fit a short piece of 3/8-inch internal diameter (ID) rubber hose over the end of the spark plug (see Haynes Hint). The flexible hose acts as a universal joint to help align the plug with the plug hole. Should the plug begin to cross-thread, the hose will slip on the spark plug, preventing thread damage. Tighten the plug to the torque listed in this Chapter’s Specifications. In the absence of a torque wrench, tighten each plug until you feel it seat, and then by a further quarter-turn only. Do not overtighten the spark plugs. 11 Attach the plug lead to the new spark plug, again using a twisting motion on the boot until it is firmly seated on the end of the spark plug. 12 Follow the above procedure for the remaining spark plugs, replacing them one at a time to prevent mixing up the spark plug leads.

1•8 Every 7500 miles or 6 months

4.4a Spark plug manufacturers

recommend using a wire-type gauge when

checking the gap - if the wire does not

slide between the electrodes with a slight

drag, adjustment is required

4.4b To change the gap, bend the side

electrode only, as indicated by the arrows,

and be very careful not to crack or chip the

porcelain insulator surrounding the

centre electrode

4.6 When removing the spark plug leads, grasp only the boot and use a

twisting/pulling motion

4.8 Use a spark plug socket with a long extension to unscrew the spark plugs

3261 Jaguar XJ6

4.1 Tools required for changing spark plugs

1 Spark plug socket - This will have special

padding inside to protect the spark plug porcelain insulator

2 Torque wrench - Although not mandatory,

use of this tool is the best way to ensure

that the plugs are tightened properly 3 Ratchet - to fit the plug socket 4 Extension - Depending on model and

accessories, you may need special

extensions and universal joints to reach

one or more of the plugs 5 Spark plug gap gauge - This gauge for

checking the gap comes in a variety of

styles. Make sure the gap for your engine

is included

4.10 Apply a coat of anti-seize compound to the spark plug threads

A length of 3/8-inch ID rubber hose will save time and prevent damaged threads when refitting the spark plugs

5 Power hydraulic system

fluid level check

Caution: Use only Castrol or Jaguar hydraulic system mineral oil (HSMO) in the power hydraulic system (available at Jaguar dealer service departments).

1 The power hydraulic system controls the ride levelling and the brake servo systems. The

fluid reservoir also supplies the power steering system on some models. The level

of the fluid should be carefully maintained. Low fluid levels can adversely affect the riding and braking capabilities of your vehicle. The power hydraulic system fluid reservoir is located on the right inner wing of the engine compartment.

1988 and 1989 models

2 The fluid level can easily be checked by viewing the reservoir sight glass. A green indicator in the sight glass indicates an OK condition, while a red indicator in the sight glass requires fluid to be added (see illustration). 3 If additional fluid is required, pop open the plastic tab located on top of the reservoir cap

(see illustration). 4 Insert the mineral oil dispensing tube into

the reservoir filler hole. Push down and turn until the dispensing tube is locked in place. 5 Add fluid until the green indicator in the sight glass appears, then release the dispensing tube by pushing downward and turning the opposite direction of refitting.

1990 to 1994 models

6 The fluid level can be checked by removing the cap and observing the level of fluid on the dipstick. 7 Wipe off the fluid with a clean rag, reinsert it, then withdraw it and read the fluid level (see illustration). The dipstick is marked so the fluid can be checked either cold or hot. The level should be at the HOT mark if the fluid was hot to the touch. It should be at the COLD mark if the fluid was cool to the touch. At no time should the fluid level drop below the add mark.

8 If additional fluid is required, pour the specified type directly into the reservoir, using a funnel to prevent spills.

6 Battery check

and general information

Warning: Certain precautions must be followed when working with the battery. Hydrogen gas,

which is highly flammable, is always present in the battery cells, so don’t smoke, and keep naked flames and sparks away from the battery. The electrolyte in the battery is actually dilute sulphuric acid, which will cause injury if splashed on your skin or in your eyes. It will also ruin clothes and painted surfaces. When removing the battery cables, always detach the negative cable first and hook it up last!

1 A routine preventive maintenance program for the battery in your vehicle is the only way to ensure quick and reliable starts. But before performing any battery maintenance, make sure that you have the proper equipment necessary to work safely around the battery

(see illustration). 2 There are also several precautions that

should be taken whenever battery maintenance is performed. Before servicing the battery, always turn the engine and all accessories off and disconnect the cable from the negative terminal of the battery. 3 The battery produces hydrogen gas, which is both flammable and explosive. Never create a spark, smoke or light a match around the battery. Always charge the battery in a ventilated area. 4 Electrolyte contains poisonous and corrosive sulphuric acid. Do not allow it to get in your eyes, on your skin or on your clothes, and

Every 7500 miles or 6 months 1•9

5.2 The power hydraulic system reservoir is located on the right-hand inner wing to check the fluid level on 1988 and 1989

models simply look through the sight glass

and note the colour of the indicator

5.3 To add fluid, remove the filler hole dust cap (arrowed)

5.7 On 1990 and later models remove the

cap and check the fluid level on the dipstick

6.1 Tools and materials required for battery maintenance

1 Face shield/safety goggles - When

removing corrosion with a brush, the acidic particles can fly up into your eyes

2 Baking soda - A solution of baking soda

and water can be used to neutralise corrosion

3 Petroleum jelly - A layer of this on the

battery posts will help prevent corrosion

4 Battery post/cable cleaner - This wire

brush cleaning tool will remove all traces of corrosion from the battery posts and cable clamps

5 Treated felt washers - Placing one of

these on each post, directly under the cable clamps, will help prevent corrosion

6 Puller - Sometimes the cable clamps are

difficult to pull off the posts, even after the nut/bolt has been completely loosened. This tool pulls the clamp straight up and off the post without damage

7 Battery post/cable cleaner - Here is

another cleaning tool which is a slightly different version of number 4 above, but it does the same thing

8 Rubber gloves - Another safety item to

consider when servicing the battery; remember that’s acid inside the battery!

3261 Jaguar XJ6

never ingest it. Wear protective safety glasses when working near the battery. Keep children away from the battery. 5 Note the external condition of the battery. If the positive terminal and cable clamp on your vehicle’s battery is equipped with a rubber protector, make sure it isn’t torn or damaged. It should completely cover the terminal. Look for any corroded or loose connections, cracks in the case or cover or loose hold-down clamps. Also check the entire length of each cable for cracks and frayed conductors. 6 If corrosion, which looks like white, fluffy deposits (see illustration) is evident, particularly around the terminals, the battery should be removed for cleaning. Loosen the cable clamp bolts, being careful to remove the ground cable first, and slide them off the terminals (see illustration). Then disconnect the hold-down clamp bolt and nut, remove the clamp and lift the battery from the engine compartment. 7 Clean the cable clamps thoroughly with a battery brush or a terminal cleaner and a solution of warm water and baking soda (see illustration). Wash the terminals and the top of the battery case with the same solution but make sure that the solution doesn’t get into the battery. When cleaning the cables, terminals and battery top, wear safety goggles and rubber gloves to prevent any solution from coming in contact with your eyes or hands. Wear old clothes too - even

diluted, sulphuric acid splashed onto clothes will burn holes in them. If the terminals have been extensively corroded, clean them up with a terminal cleaner (see illustration). Thoroughly wash all cleaned areas with plain water. 8 Make sure the battery tray is in good condition and the hold-down clamp bolt or nut is tight. If the battery is removed from the tray, make sure no parts remain in the bottom of the tray when the battery is reinstalled. When reinstalling the hold-down clamp bolt or nut, do not over-tighten it. 9 Information on removing and refitting the battery can be found in Chapter 5. Information on jump starting can be found at the front of this manual.

Cleaning

10 Corrosion on the hold-down components, battery case and surrounding areas can be removed with a solution of water and baking soda. Thoroughly rinse all cleaned areas with plain water. 11 Any metal parts of the vehicle damaged by corrosion should be covered with a zincbased primer, then painted.

Charging

Warning: When batteries are being charged, hydrogen gas, which is very explosive and flammable, is produced. Do not

smoke or allow open flames near a charging or a recently charged battery. Wear eye protection when near the battery during charging. Also, make sure the charger is unplugged before connecting or disconnecting the battery from the charger.

12 Slow-rate charging is the best way to restore a battery that’s discharged to the point where it will not start the engine. It’s also a good way to maintain the battery charge in a vehicle that’s only driven a few miles between starts. Maintaining the battery charge is particularly important in the winter when the battery must work harder to start the engine and electrical accessories that drain the battery are in greater use. 13 It’s best to use a one or two-amp battery charger (sometimes called a “trickle” charger). They are the safest and put the least strain on the battery. They are also the least expensive. For a faster charge, you can use a higher amperage charger, but don’t use one rated more than 1/10th the amp/hour rating of the battery. Rapid boost charges that claim to restore the power of the battery in one to two hours are hardest on the battery and can damage batteries not in good condition. This type of charging should only be used in emergency situations. 14 The average time necessary to charge a battery should be listed in the instructions that come with the charger. As a general rule, a trickle charger will charge a battery in 12 to 16 hours.

7 Hose and fluid leak check

1 Visually inspect the engine joint faces, gaskets and seals for any signs of water or oil leaks. Pay particular attention to the areas around the camshaft cover, cylinder head, oil filter and sump joint faces. Bear in mind that, over a period of time, some very slight seepage from these areas is to be expected what you are really looking for is any indication of a serious leak (see Haynes Hint). Should a

1•10 Every 7500 miles or 6 months

6.6a Battery terminal corrosion usually appears as light, fluffy powder

6.6b Removing a cable from the battery

post with a spanner - sometimes special

battery pliers are required for this if corrosion has damaged the nut hex

6.7a Remove all the corrosion from the

cable clamps (the inside of the clamp is

tapered to match the taper on the post, so

don’t remove too much material)

6.7b Regardless of the type of tool used to clean the battery posts, a clean, shiny

surface should be the result

3261 Jaguar XJ6

A leak in the cooling system will usually show up as white - or rust-coloured deposits on the area adjoining the leak

leak be found, renew the offending gasket or oil seal by referring to the appropriate Chapters in this manual. 2 Also check the security and condition of all the engine-related pipes and hoses. Ensure that all cable ties or securing clips are in place and in good condition. Clips which are broken or missing can lead to chafing of the hoses, pipes or wiring, which could cause more serious problems in the future. 3 Carefully check the radiator hoses and heater hoses along their entire length. Renew any hose which is cracked, swollen or deteriorated. Cracks will show up better if the hose is squeezed. Pay close attention to the hose clips that secure the hoses to the cooling system components. Hose clips can pinch and puncture hoses, resulting in cooling system leaks. 4 Inspect all the cooling system components (hoses, joint faces etc.) for leaks. A leak in the cooling system will usually show up as whiteor rust-coloured deposits on the area adjoining the leak. Where any problems of this nature are found on system components, renew the component or gasket with reference to Chapter 3. 5 From within the engine compartment, check the security of all fuel hose attachments and pipe unions, and inspect the fuel hoses and vacuum hoses for kinks, chafing and deterioration. 6 Also check the condition of the power steering fluid hoses and pipes.

8 Automatic transmission

fluid level check

1 The level of the automatic transmission fluid should be carefully maintained. Low fluid level can lead to slipping or loss of drive, while overfilling can cause foaming, loss of fluid and transmission damage. 2 The transmission fluid level should only be checked when the transmission is at its normal operating temperature.

Caution: If the vehicle has just been driven for a long time at high speed or in city traffic in hot weather, or if it has been pulling a trailer, an accurate fluid level reading cannot be obtained. Allow the fluid to cool down for about 30 minutes.

3 If the vehicle has not been driven, park the vehicle on level ground, set the handbrake, then start the engine and bring it to operating temperature. While the engine is idling, depress the brake pedal and move the selector lever through all the gear ranges, beginning and ending in Park. 4 With the engine still idling, remove the dipstick from its tube (see illustration). Check the level of the fluid on the dipstick (see

illustration) and note its condition. 5 Wipe the fluid from the dipstick with a clean

rag and reinsert it back into the filler tube until the cap seats.

6 Pull the dipstick out again and note the fluid level. If the transmission is cold, the level should be in the COLD or COOL range on the dipstick. If it is hot, the fluid level should be in the HOT range. If the level is at the low side of either range, add the specified transmission fluid through the dipstick tube with a funnel. 7 Add just enough of the recommended fluid to fill the transmission to the proper level. It takes about one pint to raise the level from the low mark to the high mark when the fluid is hot, so add the fluid a little at a time and keep checking the level until it is correct. 8 The condition of the fluid should also be checked along with the level. If the fluid at the end of the dipstick is black or a dark reddish brown colour, or if it emits a burned smell, the fluid should be changed (see Section 26). If you are in doubt about the condition of the fluid, purchase some new fluid and compare the two for colour and smell.

9 Differential oil level check

1 The differential has a check/fill plug which must be removed to check the lubricant level. If the vehicle is raised to gain access to the plug, be sure to support it safely on axle stands - DO NOT crawl under the vehicle when it’s supported only by the jack!

2 Remove the lubricant check/fill plug from the differential (see illustration). Use a 3/8-inch drive ratchet and a short extension to unscrew the plug. 3 Use your little finger as a dipstick to make sure the lubricant level is even with the bottom of the plug hole. If not, use a syringe or squeeze bottle to add the recommended lubricant until it just starts to run out of the opening.

4 Refit the plug and tighten it securely.

10 Exhaust system check

1 With the engine cold (at least three hours after the vehicle has been driven), check the complete exhaust system from its starting point at the engine to the end of the tailpipe. This should be done on a hoist where unrestricted access is available. 2 Check the pipes and connections for evidence of leaks, severe corrosion or damage. Make sure that all brackets and hangers are in good condition and tight (see

illustration). 3 At the same time, inspect the underside of

the body for holes, corrosion, open seams, etc. which may allow exhaust gases to enter the passenger compartment. Seal all body openings with silicone or body putty. 4 Rattles and other noises can often be traced to the exhaust system, especially the mounts and hangers. Try to move the pipes,

Every 7500 miles or 6 months 1•11

9.2 The differential check/fill plug is

located on the rear of the differential

housing - place your finger in the filler plug

hole to make sure the lubricant level is

even with the bottom of the hole

10.2 Check the exhaust system hangers (arrowed) for damage and cracks

3261 Jaguar XJ6

8.4a The automatic transmission dipstick (arrowed) is located in a tube which

extends forward from the transmission

8.4b Check the automatic transmission fluid with the engine idling at operating

temperature and the gear selector in Park,

then add fluid to bring the level to the

upper mark

silencer and catalytic converter. If the components can come in contact with the body or suspension parts, secure the exhaust system with new mounts. 5 Check the running condition of the engine by inspecting inside the end of the tailpipe. The exhaust deposits here are an indication of engine state-of-tune. If the pipe is black and sooty or coated with white deposits, the engine is in need of a tune-up, including a thorough fuel system inspection.

11 Braking system - general

check and adjustment

Warning: The dust created by the brake system may contain asbestos, which is harmful to

your health. Never blow it out with compressed air and don’t inhale any of it. An approved filtering mask should be worn when working on the brakes. Do not, under any circumstances, use petroleumbased solvents to clean brake parts. Use brake system cleaner only! Try to use nonasbestos replacement parts whenever possible.

Note: For detailed photographs of the brake system, refer to Chapter 9.

1 In addition to the specified intervals, the brakes should be inspected every time the wheels are removed or whenever a defect is suspected. Any of the following symptoms could indicate a potential brake system defect: The vehicle pulls to one side when the brake pedal is depressed; the brakes make squealing or dragging noises when applied; brake pedal travel is excessive; the pedal pulsates; brake fluid leaks, usually onto the inside of the tyre or wheel. 2 The disc brakes have built-in electrical wear indicators which cause a warning lamp to illuminate on the instrument panel when they’re worn to the renewal point. When the warning light comes on, replace the pads immediately or expensive damage to the discs can result.

3 Loosen the wheel nuts. 4 Raise the vehicle and place it securely on

axle stands. 5 Remove the wheels.

Disc brakes

6 There are two pads (an outer and an inner) in each caliper. The pads are visible through inspection holes in each caliper (see Haynes

Hint). 7 Check the pad thickness by looking at each

end of the caliper and through the inspection hole in the caliper body. If the lining material is less than the thickness listed in this Chapter’s Specifications, replace the pads. Note: Keep

in mind that the lining material is riveted or bonded to a metal backing plate and the metal portion is not included in this measurement.

8 If it is difficult to determine the exact thickness of the remaining pad material by the above method, or if you are at all concerned about the condition of the pads, remove the caliper(s), then remove the pads from the calipers for further inspection (see Chapter 9). 9 Once the pads are removed from the calipers, clean them with brake cleaner and re-measure them with a ruler or a vernier caliper. 10 Measure the disc thickness with a micrometer to make sure that it still has service life remaining. If any disc is thinner than the specified minimum thickness, replace it (refer to Chapter 9). Even if the disc has service life remaining, check its condition. Look for scoring, gouging and burned spots. If these conditions exist, remove the disc and have it resurfaced (see Chapter 9). 11 Before refitting the wheels, check all brake lines and hoses for damage, wear, deformation, cracks, corrosion, leakage, bends and twists, particularly in the vicinity of the rubber hoses at the calipers (see illustration). Check the clamps for tightness and the connections for leakage. Make sure that all hoses and lines are clear of sharp edges, moving parts and the exhaust system. If any of the above conditions are noted, repair, reroute or replace the lines and/or fittings as necessary (see Chapter 9).

Hydraulic brake servo check

12 Sit in the driver’s seat and perform the following sequence of tests. 13 Start the engine, run it for about a minute and turn it off. Then firmly depress the brake several times - the pedal travel should decrease with each application. 14 With the brake fully depressed, start the engine - the pedal should move down a little when the engine starts. 15 Depress the brake, stop the engine and hold the pedal in for about 30 seconds - the pedal should neither sink nor rise. 16 If your brakes do not operate as described above when the preceding tests are performed, the brake servo is either in need of repair or has failed. Refer to Chapter 9 for the removal procedure.

Handbrake

17 Slowly pull up on the handbrake and count the number of clicks you hear until the handle is up as far as it will go. The adjustment should be within the specified number of clicks listed in this Chapter’s Specifications. If you hear more or fewer clicks, it’s time to adjust the handbrake (refer to Chapter 9). 18 An alternative method of checking the handbrake is to park the vehicle on a steep hill with the handbrake set and the transmission in Neutral (be sure to stay in the vehicle during this check!). If the handbrake cannot prevent the vehicle from rolling, it is in need of adjustment (see Chapter 9). Whenever a fault is suspected, the brake discs should be removed and the handbrake assemblies themselves should be visually inspected.

12 Steering

and suspension check

Note: The steering linkage and suspension components should be checked periodically. Worn or damaged suspension and steering linkage components can result in excessive and abnormal tyre wear, poor ride quality and vehicle handling and reduced fuel economy. For detailed illustrations of the steering and suspension components, refer to Chapter 10.

With the wheels on the ground

1 Park the vehicle on level ground, turn the engine off and set the handbrake. Check the tyre pressures and check that the wheel nuts are tightened to the specified torque. 2 Push down at one corner of the vehicle, then release it while noting the movement of the body. It should stop moving and come to rest in a level position with one or two bounces. When bouncing the vehicle up and down, listen for squeaks and noises from the suspension components. 3 If the vehicle continues to move up-anddown or if it fails to return to its original

1•12 Every 7500 miles or 6 months

11.11 Check along the brake hoses and at each fitting (arrowed) for

deterioration and cracks

3261 Jaguar XJ6

You will find an inspection hole like this in each caliper - placing a ruler across the hole should enable you to determine the thickness of remaining pad material for both inner and outer pads

position, a worn or weak shock absorber is probably the reason. 4 Repeat the above check at each of the three remaining corners of the vehicle.

Under the vehicle

5 Raise the vehicle with a trolley jack and support it securely on axle stands. See “Jacking and towing” for proper jacking points. 6 Check the shock absorbers for evidence of fluid leakage. Make sure that any fluid noted is from the shocks and not from any other source. Also check the rubber mounts at each end for deterioration If the shock absorbers fail any of the tests above replace the shocks as a set. 7 Check the tyres for irregular wear patterns and proper inflation. See “Weekly checks” for information regarding tyre wear. 8 Inspect the universal joint between the steering shaft and the steering gear housing. Check the steering gear housing for grease leakage. Make sure that the dust seals and boots are not damaged and that the boot clamps are not loose (see illustration). Check the steering linkage for looseness or damage. Look for loose bolts, broken or disconnected parts and deteriorated rubber bushings on all suspension and steering components (see illustration). While an assistant turns the steering wheel from side to side, check the steering components for free movement, chafing and binding. If the steering components do not seem to be reacting with the movement of the steering wheel, try to determine where the slack is located. 9 Check the balljoints moving each lower arm up and down with a crowbar to ensure that its balljoint has no play. If any balljoint does have play, replace it. See Chapter 10 for the front balljoint renewal procedure. Check the tie-rod ends for excessive play. 10 Inspect the balljoint and tie-rod end boots for damage and leaking grease (see illustration. Replace the balljoints and tie-rod ends with new ones if they are damaged (see Chapter 10).

13 Seat belt check

1 Check the seat belts, buckles, latch plates and guide loops for any obvious damage or signs of wear. 2 Make sure the seat belt reminder light comes on when the key is turned on. 3 The seat belts are designed to lock up during a sudden stop or impact, yet allow free movement during normal driving. The retractors should hold the belt against your chest while driving and rewind the belt when the buckle is unlatched. 4 If any of the above checks reveal problems with the seat-belt system, replace parts as necessary. Note: Check with your local dealer

service department; the seat belt system should be covered under the factory warranty.

14 General lubrication

1 Obtain a good quality, multi-purpose lithium-base grease. You’ll also need a grease gun and other materials to properly lubricate the chassis (see illustration). Occasionally

plugs will be installed rather than grease fittings. If so, grease fittings will have to be purchased and installed. 2 Look under the car and see if grease fittings or plugs are installed. If there are plugs, remove them and buy grease fittings, which will thread into the component. A dealer or motor factors will be able to supply the correct fittings. Straight, as well as angled, fittings are available. 3 For easier access under the car, raise it with a jack and place axle stands under the chassis. Make sure it’s safely supported by the stands. If the wheels are to be removed at this interval for tyre rotation or brake inspection, loosen the wheel nuts slightly while the car is still on the ground. 4 Before beginning, force a little grease out of the nozzle to remove any dirt from the end of the gun. Wipe the nozzle clean with a rag. 5 With the grease gun and plenty of clean rags, crawl under the car and begin lubricating all the front suspension parts that are equipped with a grease fitting.

6 Lubricate the rear driveshafts (see illustration). Wipe each fitting clean and push

the nozzle firmly over it. Pump the gun until grease is expelled from the U-joint cap seal. 7 Wipe away any excess grease from the components and the grease fitting. Repeat the procedure for the remaining fittings.

Every 7500 miles or 6 months 1•13

14.1 Materials required for chassis and body lubrication

3261 Jaguar XJ6

12.8a Check the steering gear dust boots for cracks and leaking steering fluid

12.8b Check the anti-roll bar bushings

(arrowed) for deterioration at the front and

the rear of the vehicle

12.10 Inspect the balljoint and tie-rod end boots for tears - tears or damage in either

boot will allow contamination of the grease

which will lead to premature failure

1 Engine oil - Light engine oil in a can like

this can be used for door and bonnet hinges

2 Graphite spray - Used to lubricate lock

cylinders

3 Grease - Grease, in a variety of types and

weights, is available for use in a grease gun.

4 Grease gun - A common grease gun,

shown here with a detachable hose and nozzle, is needed for chassis lubrication. After use, clean it thoroughly

16 Spark plug renewal

Refer to Section 4, renewing the plugs

regardless of their apparent condition.

17 Air cleaner element renewal

1 The air filter is located inside a housing at the left side of the engine compartment. To remove the air filter, release the four spring clips that secure the two halves of the air cleaner housing together, then lift the cover up and remove the air filter element (see illustration).

Caution: Never drive the car with the air cleaner removed. Excessive engine wear could result and backfiring could even cause a fire under the bonnet.

2 Wipe out the inside of the air cleaner housing. 3 Place the new filter into the air cleaner housing, making sure it seats properly.

4 Refitting the cover is the reverse of removal.

18 Fuel filter renewal

Warning: Petrol is extremely flammable, so take extra precautions when you work on

any part of the fuel system. Don’t smoke or allow open flames or bare light bulbs near the work area, and don’t work in a garage where a natural gas-type

appliance (such as a water heater or clothes dryer) with a pilot light is present. Since petrol is carcinogenic, wear latex gloves when there’s a possibility of being exposed to fuel, and, if you spill any fuel on your skin, rinse it off immediately with soap and water. Mop up any spills immediately and do not store fuel-soaked rags where they could ignite. The fuel system is under constant pressure, so, if any fuel lines are to be disconnected, the fuel pressure in the system must be relieved first (see Chapter 4 for more information). When you perform any kind of work on the fuel system, wear safety glasses and have a Class B type fire extinguisher on hand.

1 The canister type filter is mounted underneath the car on the passenger’s side frame rail just in front of the left rear tyre. 2 Depressurise the fuel system (refer to Chapter 4), then disconnect the cable from the negative terminal of the battery. 3 On 1988 to 1990 models, detach the banjo bolt from the outlet side of the filter then remove the union from the inlet side of the filter. Unscrew the filter mounting bolt and remove the filter (see illustration). 4 On 1991 to 1994 models, the fuel filter has quick-disconnect fittings that do not require

8 Clean and lubricate the handbrake cable, along with the cable guides and levers. This can be done by smearing some of the chassis grease onto the cable and its related parts with your fingers. 9 Open the bonnet and smear a little chassis grease on the bonnet latch mechanism. Have an assistant pull the bonnet release lever from inside the car as you lubricate the cable at the latch. 10 Lubricate all the hinges (door, bonnet, etc.) with engine oil to keep them in proper working order. 11 The key lock cylinders can be lubricated with spray graphite or silicone lubricant, which is available at motor factors.

12 Lubricate the door weather-stripping with silicone spray. This will reduce chafing and retard wear.

15 Road test

Instruments and electrical equipment

1 Check the operation of all instruments and electrical equipment. 2 Make sure that all instruments read correctly, and switch on all electrical equipment in turn, to check that it functions properly.

Steering and suspension

3 Check for any abnormalities in the steering, suspension, handling or road “feel”. 4 Drive the car, and check that there are no unusual vibrations or noises. 5 Check that the steering feels positive, with no excessive “sloppiness”, or roughness, and check for any suspension noises when cornering and driving over bumps.

Drivetrain

6 Check the performance of the engine and transmission, listening for any unusual noises.

7 Make sure that the engine runs smoothly when idling, and that there is no hesitation when accelerating. 8 Check that the gear changing action of the transmission is smooth and progressive and that the drive is taken up smoothly from a standing start.

Braking system

9 Make sure that the car does not pull to one side when braking, and that the wheels do not lock prematurely when braking hard. 10 Check that there is no vibration through the steering when braking. 11 Check that the handbrake operates correctly without excessive movement of the lever, and that it holds the car stationary on a slope. 12 Test the operation of the brake servo unit as follows. With the engine off, depress the footbrake four or five times to exhaust the vacuum. Hold the brake pedal depressed, then start the engine. As the engine starts, there should be a noticeable “give” in the brake pedal as vacuum builds up. Allow the engine to run for at least two minutes, and then switch it off. If the brake pedal is depressed now, it should be possible to detect a hiss from the servo as the pedal is depressed. After about four or five depressions, no further hissing should be heard, and the pedal should feel considerably harder.

1•14 Every 7500 miles or 6 months

17.1 Detach the clips and separate the

cover, then slide the filter element out of

the housing

3261 Jaguar XJ6

14.6 Grease fittings for the rear

driveshafts are located in the centre

on each U-joint

Every 15 000 miles (24 000 km) or 12 months

hand tools to remove. Simply slide back the locking collars and remove the inlet and outlet fuel lines (see illustration). Detach the filter mounting bracket and discard the old filter in a proper container. 5 Note the direction of the arrow on the outside of the filter; it should be pointed towards the front of the car. Make sure the new filter is installed so that it’s facing the proper direction. Note: Always refit new

copper washers where equipped.

6 Refit the inlet and outlet fittings then tighten the filter mounting bracket. Reconnect the battery cable, start the engine and check for leaks.

19 Ignition system check

1 The spark plug leads should be checked whenever new spark plugs are installed. 2 Begin this procedure by making a visual check of the spark plug leads while the engine is running. In a darkened garage (make sure there is adequate ventilation) start the engine and observe each plug lead. Be careful not to come into contact with any moving engine parts. If there is a break in the lead, you will see arcing or a small spark at the damaged area. If arcing is noticed, make a note to obtain new leads, then allow the engine to cool and check the distributor cap and rotor. 3 The spark plug leads should be inspected one at a time to prevent mixing up the order, which is essential for proper engine operation. Each original plug lead should be numbered to help identify its location. If the number is illegible, a piece of tape can be marked with the correct number and wrapped around the plug lead. 4 Disconnect the plug lead from the spark plug. A removal tool can be used for this purpose or you can grasp the rubber boot, twist the boot half a turn and pull the boot free. Do not pull on the lead itself. 5 Check inside the boot for corrosion, which will look like a white crusty powder.

6 Push the lead and boot back onto the end of the spark plug. It should fit tightly onto the end of the plug. If it doesn’t, remove the lead and use pliers to carefully crimp the metal connector inside the lead boot until the fit is snug. 7 Using a clean rag, wipe the entire length of the lead to remove built-up dirt and grease. Once the lead is clean, check for burns, cracks and other damage. Do not bend the lead sharply, because the conductor might break. 8 Disconnect the spark plug lead from the distributor cap. Again, pull only on the rubber boot. Check for corrosion and a tight fit. Reinsert the lead in the distributor cap. 9 Inspect the remaining spark plug leads, making sure that each one is securely fastened at the distributor and spark plug when the check is complete.

10 If new spark plug leads are required, purchase a set for your specific engine model. Remove and replace the leads one at a time to avoid mix-ups in the firing order. 11 Detach the distributor cap by unsnapping the cap retaining clips. Look inside it for cracks, carbon tracks and worn, burned or loose contacts (see illustrations). 12 Pull the rotor off the distributor shaft and examine it for cracks and carbon tracks (see illustrations). Replace the cap and rotor if any damage or defects are noted. 13 It is common practice to refit a new cap and rotor whenever new spark plug leads are installed. When refitting a new cap, remove the leads from the old cap one at a time and attach them to the new cap in the exact same location Note: If an accidental mix-up occurs,

refer to the firing order Specifications at the beginning of this Chapter.

Every 15 000 miles or 12 months 1•15

19.11a Unsnap the distributor cap

retaining clips - pull the cap up and away

to access the rotor

19.11b Shown here are some of the common defects to look for when

inspecting the distributor cap (typical cap

shown). If in doubt about its condition,

fit a new one

19.12a Pull off the rotor (arrowed) and inspect it thoroughly

19.12b Check the ignition rotor for wear

and corrosion as indicated here (if in doubt

about its condition, buy a new one)

3261 Jaguar XJ6

18.3 Remove the banjo bolt from the

outlet side (B), detach the fitting from the

inlet side (A) and unscrew the filter

mounting bolt (C)

18.4 On 1991 to 1994 models, slide back the locking collars and remove the inlet

and outlet fuel lines

20 Crankcase ventilation

system check

Refer to Chapter 6.

21 Drivebelt check and renewal

Check

1 The drivebelts, or V-belts as they are sometimes called, are located at the front of the engine and play an important role in the overall operation of the vehicle and its components. Due to their function and material make-up, the belts are prone to failure after a period of time and should be inspected and adjusted periodically to prevent major engine damage. 2 The number of belts used on a particular vehicle depends on the accessories installed. The main belt transmits power from the crankshaft to the water pump, alternator and the power steering pump. The second belt transmits power from the crankshaft to the air conditioning compressor. 3 With the engine off, open the bonnet and locate the drivebelts. With a flashlight, check each belt for separation of the adhesive rubber on both sides of the core, core separation from the belt side, a severed core, separation of the ribs from the adhesive rubber, cracking or separation of the ribs, and torn or worn ribs or cracks in the inner ridges of the ribs (see illustrations). Also check for fraying and glazing, which gives the belt a shiny appearance. Both sides of the belt should be inspected, which means you will have to twist the belt to check the underside. Use your fingers to feel the belt where you can’t see it. If any of the above conditions are evident, replace the belt (go to paragraph 7). 4 Check the belt tension by pushing firmly on the belt with your thumb at a distance halfway between the pulleys and note how far the belt

can be pushed (deflected). Measure this deflection with a ruler (see illustration). As a rule of thumb, if the distance from pulley centre-to- pulley centre is between 7 and 11 inches, the belt should deflect 1/4-inch. If the belt travels between pulleys spaced 12 to 16 inches apart, the belt should deflect 1/2-inch for a V-belt or 1/4-inch for a serpentine belt.

Adjustment

5 There are two belt tensioning mechanisms. The first one adjusts the air conditioning compressor belt, which is accessible from underneath the car. The second tensioning mechanism is above the alternator - it adjusts the tension on the main belt (the water pump, alternator and power steering pump belt). 6 The air conditioning compressor and the alternator each have a belt tensioning mechanism and pivot bolt(s) which must be loosened slightly to enable you to move the component (see illustrations). 7 After the bolts have been loosened, belt tension can be adjusted by either loosening or tightening the locknuts on the belt tensioning adjustment rod (see illustration 21.6a and b). Move the component away from the engine to

tighten the belt or toward the engine to loosen the belt. 8 Measure the belt tension using the method described in paragraph 4. Repeat this procedure until the drivebelt is adjusted properly.

Renewal

9 To replace a belt, loosen the drivebelt adjustment rod and pivot bolt as described above, slip the belt off the crankshaft pulley and remove it. If you are replacing the alternator/power steering pump belt, you’ll have to remove the air conditioning

1•16 Every 15 000 miles or 12 months

21.3a Small cracks in the underside of a

serpentine belt are acceptable -

lengthwise cracks, or missing pieces, are

cause for replacement

21.3b Here are some of the more common problems associated with V-belts (check

the belts very carefully to prevent an

untimely breakdown)

21.4 Measuring drivebelt deflection with a straightedge and ruler

21.6a To adjust the alternator/power

steering drivebelt, loosen the outer locknut

(arrowed) and the alternator pivot bolt turn the inner locknut anti-clockwise to

loosen or clockwise to tighten the belt

21.6b To adjust the air conditioning

compressor drivebelt, loosen the outer

locknut (arrowed) and the compressor

pivot bolts - turn the inner locknut anti-

clockwise to loosen or clockwise to

tighten the belt

3261 Jaguar XJ6

compressor belt first because of the way they are arranged on the crankshaft pulley. Because of this and because belts tend to wear out more or less together, it is a good idea to replace both belts at the same time. Mark each belt and its appropriate pulley groove so the new belts can be installed in their proper positions. 10 Take the old belts to the parts store in order to make a direct comparison for length, width and design. 11 After replacing a ribbed drivebelt, make sure that it fits properly in the ribbed grooves in the pulleys (see illustration). It is essential that the belt be properly centred. 12 Adjust the belt(s) in accordance with the procedure outlined above.

22 Front wheel bearing check

and adjustment

Check and repack

1 In most cases the front wheel bearings will not need servicing until the brake pads are changed. However, the bearings should be checked whenever the front of the vehicle is raised for any reason. Several items, including a torque wrench and special grease, are required for this procedure (see illustration).

2 With the vehicle securely supported on axle stands, spin each wheel and check for noise, rolling resistance and freeplay. 3 Grasp the top of each tyre with one hand and the bottom with the other. Move the wheel in-and-out on the spindle. If there’s any noticeable movement, the bearings should be checked and then repacked with grease or renewed if necessary.

4 Remove the wheel. 5 Remove the brake caliper (see Chapter 9)

and hang it out of the way on a piece of wire. A wood block of the appropriate width can be slid between the brake pads to keep them separated, if necessary. Also remove the brake disc. 6 Pry the dust cap out of the hub using a screwdriver or a hammer and chisel (see

illustration). 7 Straighten the bent ends of the cotter pin, then pull the cotter pin out of the nut lock (see illustration). Discard the cotter pin and use a

new one during reassembly. 8 Remove the locknut, nut and washer from the end of the spindle. 9 Pull the hub out slightly, then push it back into its original position. This should force the

outer bearing off the spindle enough so it can be removed (see illustration). 10 Pull the hub off the spindle. Note:

Sometimes the inner wheel bearing and grease seal remain attached to the spindle. Grasp the back of the seal with both hands and pull forward to remove them.

11 If the grease seal is not already detached from the hub, use a screwdriver to pry the seal out of the rear of the hub. As this is done, note how the seal is installed. 12 If the inner wheel bearing is not already detached from the hub, remove it at this time. 13 Use solvent to remove all traces of the old grease from the bearings, hub and spindle. A small brush may prove helpful; however make sure no bristles from the brush embed themselves inside the bearing rollers. Allow the parts to air dry. 14 Carefully inspect the bearings for cracks, heat discoloration, worn rollers, etc. Check the bearing races inside the hub for wear and damage. If the bearing races are defective, the hubs should be taken to a machine workshop with the facilities to remove the old races and press new ones in. Note that the bearings and races come as matched sets

Every 15 000 miles or 12 months 1•17

22.1 Tools and materials needed for front wheel bearing maintenance

1 Hammer 2 Grease - High-temperature grease that is

formulated specially for front wheel bearings should be used

3 Wood block - If you have a scrap piece

of 2x4, it can be used to drive the new seal into the hub

4 Needle-nose pliers - Used to straighten

and remove the cotter pin in the spindle

5 Torque wrench - This is very important in

this procedure; if the bearing is too tight, the wheel won’t turn freely - if it’s too loose, the wheel will “wobble” on the spindle. Either way, it could mean extensive damage

6 Screwdriver - Used to remove the seal

from the hub (a long screwdriver is preferred)

7 Socket/breaker bar - Needed to loosen the

nut on the spindle if it’s extremely tight

8 Brush - Together with some clean

solvent, this will be used to remove old grease from the hub and spindle

22.6 Dislodge the dust cap by working around the outer circumference with a

hammer and chisel

22.7 Remove the cotter pin and discard it use a new one when the hub is reinstalled

22.9 Pull the hub assembly forward

slightly - then push it back into position to

dislodge the outer wheel bearing

3261 Jaguar XJ6

21.11 When refitting ribbed (serpentine) drivebelts, make sure the belt is centred

between the pulley edges (arrowed) - it

must not overlap either edge of the pulley

and old bearings should never be installed on new races. 15 Use high-temperature front wheel bearing grease to pack the bearings. Work the grease completely into the bearings, forcing it between the rollers, cone and cage from the back side (see illustration). 16 Apply a thin coat of grease to the spindle at the outer bearing seat, inner bearing seat, shoulder and seal seat. 17 Put a small quantity of grease inboard of each bearing race inside the hub. Using your finger, form a dam at these points to provide extra grease availability and to keep thinned grease from flowing out of the bearing (see

illustration). 18 Place the grease-packed inner bearing

into the rear of the hub and put a little more grease outboard of the bearing. 19 Place a new seal over the inner bearing and tap the seal evenly into place until it’s flush with the hub (see illustration). 20 Carefully place the hub assembly onto the spindle and push the grease-packed outer bearing into position (see illustration).

Adjustment

21 Refit the washer and spindle nut. Tighten the nut only slightly (no more than 16Nm/12 lbf ft of torque). 22 Rotate the hub slowly in a forward direction while tightening the spindle nut to

approximately 27Nm (20 lbf ft) to seat the bearings. Remove any grease or burrs which could cause excessive bearing play later. 23 Loosen the spindle nut 1/4-turn, then using your hand (not a spanner of any kind), tighten the nut until it’s snug. Refit the nut lock and a new cotter pin through the hole in the spindle and the slots in the nut lock. If the nut lock slots don’t line up, remove the nut lock and turn it slightly until they do (see

illustration). 24 Bend the ends of the cotter pin until

they’re flat against the nut. Cut off any extra length which could interfere with the dust cap. 25 Refit the dust cap, tapping it into place with a hammer. 26 Refit the brake disc and caliper in the reverse order of removal (see Chapter 9). 27 Refit the wheel on the hub and tighten the wheel nuts. 28 Grasp the top and bottom of the tyre and check the bearings in the manner described earlier in this Section. 29 Lower the vehicle and tighten the wheel nuts to the torque listed in this Chapter’s Specifications.

23 Propshaft check

1 Referring to Chapter 8, check the propshaft centre bearing, universal joint and flexible coupling for signs of wear or damage and check that the propshaft fixings are tightened to the specified torque.

24 Front wheel alignment check

1 Accurate wheel alignment requires access to specialised test equipment and as such should be entrusted to a suitably equipped Jaguar dealer or a tyre specialist (refer to Chapter 10).

25 Headlight beam check

1 Accurate adjustment of the headlight beam is only possible using optical beam-setting equipment, and this work should therefore be carried out by a Jaguar dealer or garage with the necessary facilities (see Chapter 12).

1•18 Every 15 000 miles or 12 months

22.15 Work the grease completely into the bearing rollers

22.17 Apply a thin layer of grease to the inner and outer bearing races

22.19 After refitting the inner wheel

bearing into the hub - press the grease

seal into place

22.20 Refit the hub assembly onto the

spindle - then push the grease-packed

outer bearing into position

22.23 Position the nut lock on the spindle nut so that it lines up with the cotter pin

hole - DO NOT loosen the spindle nut from

its snug position

3261 Jaguar XJ6

26 Automatic transmission fluid

and filter renewal

1 At the specified time intervals, the transmission fluid should be drained and renewed. Since the fluid will remain hot long after driving, perform this procedure only after the engine has cooled down completely. 2 Before beginning work, purchase the specified transmission fluid and a new filter. 3 Other tools necessary for this job include axle stands to support the vehicle in a raised position, a drain pan capable of holding at least eight pints, newspapers and clean rags.

4 Raise the vehicle and support it securely on axle stands. 5 Place the drain pan under the drain plug in the bottom of the transmission sump pan. Remove the plug and allow the fluid to drain

(see illustration). 6 Refit the drain plug, then move the drain

pan underneath the dipstick tube. Loosen the dipstick tube collar and let the remaining fluid drain (see illustrations). 7 Remove the sump pan mounting bolts and brackets (see illustration). 8 Detach the sump pan from the transmission and lower it, keeping it as horizontal as possible in order not to spill too much of the remaining fluid (see illustration).

9 Drain the remaining fluid from the transmission sump pan, clean it with solvent and dry it with compressed air. Be sure to clean the metal filings from the magnet, if equipped. 10 Remove the screws and detach the filter from the valve body (see illustrations). 11 Refit the new O-ring and filter, being sure to tighten the bolts securely. 12 Carefully clean the fluid pan-totransmission sealing surface. 13 Make sure the gasket surface on the transmission sump pan is completely clean, then refit the gasket. Put the sump pan in place against the transmission and refit the brackets and bolts. working around the sump pan, tighten each bolt a little at a time until the torque listed in this Chapter’s Specifications is reached. Don’t overtighten the bolts! Connect the dipstick tube and tighten the collar securely. 14 Lower the vehicle and add the specified amount of fluid through the filler tube (see Section 8). 15 With the transmission in Park and the handbrake set, run the engine at fast idle, but don’t race it. 16 Move the gear selector through each position, and then back to Park. Check the fluid level. 17 Be sure to check underneath the car for any leaks after the first few miles of driving.

Every 30 000 miles (48 000 km) or 2 years

Every 30 000 miles or 2 years 1•19

26.6a Unscrew the dipstick tube collar 26.6b Detach the tube and let the remaining fluid drain

26.7 Use a socket and extension to

remove the transmission sump pan bolts

and brackets

26.8 Lower the sump pan from the transmission

26.10a Use a Torx-head driver to remove the filter bolts (arrowed) . . .

3261 Jaguar XJ6

26.5 Using an Allen spanner remove the drain plug located in the bottom of the

transmission sump pan

26.10b . . . then remove the fluid filter from the transmission

26.10c Be sure to remove the old O-ring

from the transmission - always use a new

O-ring when replacing the filter

30 Coolant renewal

Warning: Do not allow engine coolant (antifreeze) to come in contact with your skin or painted

surfaces of the vehicle. Rinse off spills immediately with plenty of water. Antifreeze is highly toxic if ingested. Never leave antifreeze laying around in an open container or in puddles on the floor; children and pets are attracted by it’s sweet smell and may drink it. Check with local authorities about disposing of used antifreeze. Your local authority may have collection centres which will see that antifreeze is disposed of safely.

1 Periodically, the cooling system should be drained, flushed and refilled to replenish the antifreeze mixture and prevent formation of rust and corrosion, which can impair the performance of the cooling system and cause engine damage. When the cooling system is serviced, all hoses and the radiator cap should be checked and renewed if necessary.

Draining

2 Apply the handbrake and block the wheels. If the vehicle has just been driven, wait several hours to allow the engine to cool down before beginning this procedure.

3 Remove the expansion tank pressure cap (see illustration). 4 Move a large container under the radiator

drain to catch the coolant. Then using a large

screwdriver, open the radiator drain plug and direct the coolant into the container (see

illustration).

27 Differential oil renewal

1 Drive the car for several miles to warm up the differential lubricant, then raise the car and support it securely on axle stands. 2 Move a drain pan, rags, newspapers and the required tools under the car. 3 Remove the check/fill plug from the differential. If necessary refer to Section 9 for the check/fill plug location. 4 With the drain pan under the differential, use a ratchet and socket to loosen the drain plug (see illustration). Note: A special pipe

plug socket may be required to complete this procedure.

5 Once loosened, carefully unscrew it with your fingers until you can remove it from the case. Since the lubricant will be hot, wear a rubber glove to prevent burns. 6 Allow all of the oil to drain into the pan, then replace the drain plug and tighten it securely. 7 Refer to Section 9 and fill the differential with lubricant.

8 Refit the fill plug and tighten it securely. 9 Lower the vehicle. Check for leaks at the

drain plug after the first few miles of driving.

28 Brake fluid renewal

Warning: Brake fluid can harm your eyes and damage painted surfaces, so use extreme

caution when handling or pouring it. Do not use brake fluid that has been standing open or is more than one

year old. Brake fluid absorbs moisture from the air. Excess moisture can cause a dangerous loss of braking effectiveness.

1 At the specified time intervals, the brake fluid should be drained and renewed. Since the brake fluid may drip or splash when pouring it, place plenty of rags around the master cylinder to protect any surrounding painted surfaces. 2 Before beginning work, purchase the specified type of brake fluid. 3 Remove the cap from the master cylinder reservoir. 4 Using a hand suction pump or similar device, withdraw the fluid from the master cylinder reservoir. 5 Add new fluid to the master cylinder until it rises to the base of the filler neck. 6 Bleed the brake system as described in Chapter 9 at all four brakes until new and uncontaminated fluid flows from the bleed screw. 7 Refill the master cylinder with fluid and check the operation of the brakes. The pedal should feel solid when depressed, with no sponginess.

Warning: Do not drive the car if you are in any doubt about the braking system.

1•20 Every 30 000 miles or 2 years

27.4 The differential drain plug (arrowed)

is accessible through a hole located in the

middle of the differential support brace

30.3 Push the expansion tank pressure

cap downward and rotate anti-clockwise -

never remove it when the engine is hot!

3261 Jaguar XJ6

Every 60 000 miles (96 000 km)

29 Handbrake shoes check

1 Remove the rear discs and inspect the handbrake shoes as described in Chapter 9. If the shoes are worn or damaged they must be renewed.

Warning: The dust created by

the brake system may contain

asbestos, which is harmful to

brake system cleaner only! Try to use nonasbestos replacement parts whenever possible.

Every 2 years, regardless of mileage

5 After the coolant stops flowing out of the

radiator, move the container under the engine block drain plug. Remove the plug and let the coolant in the block to drain (see illustration). 6 While the coolant is draining from the engine block, check the condition of the radiator hoses, heater hoses and clamps (refer to Section 7 if necessary). 7 Replace any damaged clamps or hoses (see Chapter 3).

Flushing

8 Once the system is completely drained, flush the radiator with fresh water from a

garden hose until water runs clear at the drain. The flushing action of the water will remove sediments from the radiator but will not remove more serious rust and scale from the engine and cooling tube surfaces. 9 These deposits can be removed by using proprietary chemical cleaners. It should be stressed, however, that these should only need to be used if the system has been neglected. Follow the procedure outlined in their manufacturer’s instructions. If the radiator is severely corroded, damaged or leaking, it should be removed (see Chapter 3) and taken to a radiator repair workshop.

10 On 1988 and 1989 models remove the overflow hose from the coolant recovery reservoir. Drain the reservoir and flush it with clean water, then reconnect the hose (see Chapter 3).

Refilling

11 Close and tighten the radiator drain. Refit and tighten the engine block drain plugs. 12 Make sure the heater temperature control is in the maximum heat position. 13 Slowly refill the expansion tank with a mixture of antifreeze and water until the coolant reaches the base of the filler neck. 14 Leave the expansion tank pressure cap off and run the engine in a well-ventilated area until the thermostat opens (coolant will begin flowing through the radiator and the upper radiator hose will become hot). Race the engine two or three times under no load. 15 Turn the engine off and let it cool. Add more coolant mixture to bring the level back up to the base of the filler neck. 16 Squeeze the upper radiator hose to expel air, then add more coolant mixture if necessary. Refit the expansion tank pressure cap. 17 Start the engine, allow it to reach normal operating temperature and check for leaks.

Every 2 years 1•21

3261 Jaguar XJ6

30.4 The radiator drain fitting (arrowed) located at the bottom of the radiator

30.5 The block drain plug (arrowed) is located on the right side of the block

3261 Jaguar XJ6

Chapter 2 Part A

Engine in-car repair procedures

General

Cylinder numbers (front to rear) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2-3-4-5-6

Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5-3-6-2-4

Displacement:

3.2 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3239 cc

3.6 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3590 cc

4.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3980 cc

Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.0 mm (3.583 inches)

Stroke:

3.2 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.0 mm (3.268 inches)

3.6 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.0 mm (3.622 inches)

4.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.0 mm (4.016 inches)

Camshafts and lifters

Journal diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26.9370 to 26.9494 mm (1.0605 to 1.0610 inches)

Bearing oil clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.037 to 0.063 mm (0.0014 to 0.0024 inch)

Runout limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0406 mm (0.0016 inch)

Lobe lift (maximum variation between lobes) . . . . . . . . . . . . . . . . . . . . . 0.0127 mm (0.005 inch)

Valve lifter

Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.34 to 33.35 mm (1.3126 to 1.3130 inches)

Oil clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.020 to 0.050 mm (0.0008 to 0.0020 inch)

Valve clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 to 0.36 mm (0.012 to 0.014 inch)

Oil pump

Outer rotor to body clearance, maximum . . . . . . . . . . . . . . . . . . . . . . . 0.2 mm (0.0079 inch)

Outer rotor OD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69.774 to 69.825 mm (2.7470 to 2.7490 inches)

Rotor thickness, inner and outer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.962 to 27.975 mm (1.1008 to 1.1013 inches)

Clearance over rotors, maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 mm (0.0039 inch)

Auxiliary shaft - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Camshafts and lifters - removal, inspection and refitting . . . . . . . . . 10

CHECK ENGINE light . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6

Crankshaft front oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Crankshaft rear oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Cylinder compression check . . . . . . . . . . . . . . . . . . . . See Chapter 2B

Cylinder head - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 11

Drivebelt check, adjustment and renewal . . . . . . . . . . . See Chapter 1

Driveplate - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Engine mounts - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . 16

Engine oil and filter change . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Engine overhaul - general information . . . . . . . . . . . . . See Chapter 2B

Engine - removal and refitting . . . . . . . . . . . . . . . . . . . See Chapter 2B

Exhaust manifolds - removal and refitting . . . . . . . . . . . . . . . . . . . . . 6

General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Intake manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 5

Sump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Oil pump - removal, inspection and refitting . . . . . . . . . . . . . . . . . . . 13

Repair operations possible with the engine in the vehicle . . . . . . . . 2

Spark plug renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Timing chains and sprockets - removal, inspection and refitting . . . 8

Top Dead Centre (TDC) for number one piston - locating . . . . . . . . . 3

Valve cover - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Valves - servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 2B

Water pump - removal and refitting . . . . . . . . . . . . . . . . See Chapter 3

2A•1

Specifications

Contents

Easy, suitable for

novice with little experience

Fairly easy, suitable for beginner with some experience

Fairly difficult,

suitable for competent DIY mechanic

Difficult, suitable for experienced DIY mechanic

Very difficult,

suitable for expert DIY or professional

Degrees of difficulty

Torque wrench settings* Nm lbf ft

Camshaft bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Camshaft sprocket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Crankshaft damper-to-crankshaft bolt

3.2 and 3.6 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 151

4.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 to 220 133 to 162

Crankshaft pulley to damper bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Crankshaft rear oil seal retainer bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Crankshaft sensor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Cylinder head bolts

Step 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 44

Step 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tighten an additional 90° (1/4 turn)

Driveplate bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 to 149 91 to 110

Engine mounts

To engine block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 to 66 36 to 39

To chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 24 16 to 18

Exhaust manifold heat shield fasteners . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Exhaust manifold nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Intake manifold nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Oil pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Sump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Sump bolts, adapter to pan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 to 54 36 to 40

Timing chain cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 to 27 16 to 20

Valve cover screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 to 12 7 to 9

*Note: Refer to Part B for additional specifications

2A•2 Engine in-car repair procedures

3261 Jaguar XJ6

1 General information

This Part of Chapter 2 is devoted to in-car repair procedures for the in-line six-cylinder engines. All information concerning engine removal and refitting and engine block and cylinder head overhaul can be found in Part B of this Chapter.

The following repair procedures are based on the assumption that the engine is installed in the car. If the engine has been removed from the car and mounted on a stand, many of the steps outlined in this Part of Chapter 2 will not apply. We have photographed some incar engine procedures with the engine on a stand for photographic purposes.

The Specifications included in this Part of Chapter 2 apply only to the procedures contained in this Part. Part B of Chapter 2 includes the Specifications necessary for cylinder head and engine block rebuilding.

2 Repair operations possible

with the engine in the car

Many repair operations can be accomplished without removing the engine from the car.

Clean the engine compartment and the exterior of the engine with some type of degreaser before any work is done. It will make the job easier and help keep dirt out of the internal areas of the engine.

Depending on the components involved, it

may be helpful to remove the bonnet to improve access to the engine as repairs are performed (refer to Chapter 11 if necessary). Cover the wings to prevent damage to the paint. Special pads are available, but an old bedspread or blanket will also work.

If vacuum, exhaust, oil or coolant leaks develop, indicating a need for gasket or seal renewal, the repairs can generally be made with the engine in the car. The intake and exhaust manifold gaskets, crankshaft oil seals and cylinder head gasket are all accessible with the engine in place (although rear oil seal renewal involves removal of the transmission). The sump is difficult for a home mechanic to replace without a hoist and other specialised equipment, since the front suspension, steering and crossmember must be lowered to allow enough clearance for sump removal. If such equipment is not available, the alternative would be to remove the engine for renewal of the sump or oil pump. Note: We

assume that the home mechanic does not have access to the specialised equipment, and have photographed our subject engine out of the car for some procedures.

Exterior engine components, such as the intake and exhaust manifolds, the water pump, the starter motor, the alternator, the distributor and the fuel system components can be removed for repair with the engine in place.

Since the cylinder head can be removed with the engine in-car, camshaft and valve component servicing can also be accomplished. Renewal of the timing chains and sprockets is also possible with the engine in-car.

3 Top Dead Centre (TDC) for

number one piston - locating

Note: The following procedure is based on the assumption that the distributor is correctly installed. If you are trying to locate TDC to refit the distributor correctly, piston position must be determined by feeling for compression at the number one spark plug hole, then aligning the ignition timing marks (see paragraph 8).

1 Top Dead Centre (TDC) is the highest point in the cylinder that each piston reaches as it travels up the cylinder bore. Each piston reaches TDC on the compression stroke and again on the exhaust stroke, but TDC generally refers to piston position on the compression stroke. 2 Positioning the piston(s) at TDC is an essential part of many procedures such as camshaft and timing chain/sprocket removal and distributor removal. 3 Before beginning this procedure, be sure to place the transmission in Neutral and apply the handbrake or block the rear wheels. Also, disable the ignition system by detaching the coil wire from the centre terminal of the distributor cap and grounding it on the engine block with a jumper wire. Remove the spark plugs (see Chapter 1). 4 In order to bring any piston to TDC, the crankshaft must be turned using one of the methods outlined below. When looking at the timing chain end of the engine, normal crankshaft rotation is clockwise.

a) The preferred method is to turn the

crankshaft with a socket and ratchet

attached to the bolt threaded into the front of the crankshaft. Apply pressure on the bolt in a clockwise direction only. Never turn the bolt anti-clockwise.

b) A remote starter switch, which may save

some time, can also be used. Follow the instructions included with the switch. Once the piston is close to TDC, use a socket and ratchet as described in the previous paragraph.

c) If an assistant is available to turn the

ignition switch to the Start position in short bursts, you can get the piston close to TDC without a remote starter switch. Make sure your assistant is out of the car, away from the ignition switch, then use a socket and ratchet as described in Paragraph a) to complete the procedure.

5 Note the position of the terminal for the number one spark plug lead on the distributor cap. If the terminal isn’t marked, follow the plug lead from the number one cylinder spark plug to the cap. 6 Use a felt-tip pen or chalk to make a mark on the distributor body directly under the number one terminal (see Chapter 5). 7 Detach the cap from the distributor and set it aside (see Chapter 1 if necessary). 8 Turn the crankshaft until the small triangle cast into the front edge of the crankshaft sensor ring is aligned with the bottom edge of the timing pointer located at the front of the engine (see illustration). 9 Look at the distributor rotor - it should be pointing directly at the mark you made on the distributor body. If so, you are at TDC for number 1 cylinder. 10 If the rotor is 180° off, the number one piston is at TDC on the exhaust stroke. 11 To get the piston to TDC on the compression stroke, turn the crankshaft one complete revolution (360°) clockwise. The rotor should now be pointing at the mark on the distributor. When the rotor is pointing at the number one spark plug lead terminal in the distributor cap and the ignition timing marks are aligned, the number one piston is at

TDC on the compression stroke. Note: If it’s

impossible to align the ignition timing marks when the rotor is pointing at the mark on the distributor body, the timing chain may have jumped the teeth on the pulleys or may have been installed incorrectly.

12 After the number one piston has been positioned at TDC on the compression stroke, TDC for any of the remaining cylinders can be located by turning the crankshaft and following the firing order. Mark the remaining spark plug lead terminal locations on the distributor body just like you did for the number one terminal, then number the marks to correspond with the cylinder numbers. As you turn the crankshaft, the rotor will also turn. When it’s pointing directly at one of the marks on the distributor, the piston for that particular cylinder is at TDC on the compression stroke.

4 Valve cover -

removal and refitting

Removal

1 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make

sure you have the correct activation code before disconnecting the battery.

2 Detach the PCV hose from the valve cover (see illustration). 3 Remove the spark plug leads from the

spark plugs, handling them by the boots and not pulling on the wires. 4 Remove the valve cover mounting screws, then detach the valve cover and gasket from the cylinder head. If the valve cover is stuck to the cylinder head, bump the end with a wood block and a hammer to jar it loose. If that doesn’t work, try to slip a flexible putty knife between the cylinder head and valve cover to break the seal.

Caution: Don’t pry at the valve cover-tocylinder head joint or damage to the sealing surfaces may occur, leading to oil leaks after the valve cover is reinstalled.

Refitting

5 The mating surfaces of the cylinder head and valve cover must be clean when the valve cover is installed. If there’s residue or oil on the mating surfaces when the valve cover is installed, oil leaks may develop. 6 Apply RTV sealant around the two halfcircle rubber plugs at the rear of the cylinder head (see illustration). 7 Using a new gasket and spark plug tube seals, refit the valve cover (see illustration).

Engine in-car repair procedures 2A•3

4.6 Apply RTV sealant to the half-circle plugs and insert them into the cylinder

head before refitting the valve cover

4.7 Press the valve cover gasket into the groove around the valve cover and fit a

new set of spark plug tube seals (arrowed)

3261 Jaguar XJ6

3.8 Align the mark on the crankshaft sensor ring (arrowed) with the bottom edge of the pointer on the front cover

4.2 Disconnect the PCV hose (arrowed) from the valve cover, then pull the spark plug leads out by their boots, not the leads

8 Tighten the screws to the torque listed in

this Chapter’s Specifications in three or four equal steps. 9 Refit the remaining components, start the engine and check for oil leaks.

5 Intake manifold -

removal and refitting

Removal

1 Disconnect the negative cable from the battery.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Refer to Chapter 4 to remove the accelerator and cruise-control linkage, safely relieve the fuel system pressure, and disconnect the fuel supply lines. 3 Label or mark and detach the PCV and vacuum hoses connected to the intake manifold, (see illustration). 4 The intake manifold can be removed with the injectors and fuel rail still in place. Disconnect the electrical connectors at each injector (label them first for reassembly). If the injectors are to be removed from the intake manifold, refer to Chapter 4. 5 Refer to Chapter 4 and remove the throttle body.

6 Remove the three nuts retaining the oil filler tube bracket, then pull the tube up as far as possible (see illustrations). 7 Remove the ground strap and intake manifold mounting nuts/bolts, then detach the intake manifold from the engine (see illustrations).

Refitting

8 Clean the mating surfaces of the intake manifold and the cylinder head mounting surface with lacquer thinner or acetone. If the gasket shows signs of leaking, have the manifold checked for warpage at an automotive machine workshop and resurfaced if necessary. 9 Refit a new gasket, then position the intake manifold on the cylinder head and refit the nuts/bolts (see illustration). 10 Tighten the nuts/bolts in three or four equal steps to the torque listed in this Chapter’s Specifications. Work from the centre out towards the ends to avoid warping the manifold. 11 Refit the remaining parts in the reverse order of removal. 12 Before starting the engine, check the throttle linkage for smooth operation. 13 Run the engine and check for coolant and vacuum leaks. 14 Road test the car and check for proper operation of all accessories, including the cruise control system.

6 Exhaust manifolds -

removal and refitting

Warning: The engine must be completely cool before beginning this procedure.

Removal

1 Disconnect the negative cable from the battery.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 On 1990 and later models, disconnect the EGR pipe and remove the EGR valve from the top of the exhaust manifold (see Chapter 6). 3 Apply penetrating oil to the exhaust manifold mounting nuts/bolts, and the nuts retaining the exhaust pipes to the manifolds. After the nuts have soaked, remove the nuts retaining the exhaust pipes to the manifolds and the lower bolt from the heat shield (see

illustration). 4 Remove the heat shield from the exhaust manifolds (see illustration). 5 Disconnect the electrical connector to the

oxygen sensor. Unless the oxygen sensor is being renewed, leave the sensor in place. 6 Remove the nuts/bolts and detach the manifolds and gaskets (see illustration).

2A•4 Engine in-car repair procedures

5.3 The various hoses should be marked to ensure correct refitting

5.6a Remove the oil filler tube bracket nuts (arrowed) . . .

5.6b . . . pull the tube up to dislodge it from the housing - it won’t come out, but can be removed with the intake manifold

5.7a Remove the ground strap from the

front stud (arrowed), and the engine wiring

harness clips from the other studs

5.7b Remove the intake manifold bolts/

nuts and remove the intake manifold - the

upper fasteners are studs/nuts, while the

lower row are bolts (two arrowed)

5.9 Refit the new intake manifold gasket

over the studs (arrowed) refit the manifold

3261 Jaguar XJ6

Refitting

7 Use a scraper to remove all traces of old gasket material and carbon deposits from the manifold and cylinder head mating surfaces. If the gasket was leaking, have the manifold checked for warpage at an automotive machine workshop and resurfaced if necessary. 8 Position new gaskets over the cylinder head studs (see illustration). Note: The

marks on the gasket should face out (away from the cylinder head) and the arrow should point toward the rear of the engine.

9 Refit the manifolds and thread the mounting nuts/bolts into place. 10 Working from the centre out, tighten the nuts/bolts to the torque listed in this Chapter’s Specifications in three or four equal steps. 11 Refit the remaining parts in the reverse order of removal. 12 Run the engine and check for exhaust leaks.

7 Crankshaft front oil seal -

renewal

1 Disconnect the negative cable from the battery.

Caution: If the stereo in your vehicle is

equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Refer to Chapter 1 and remove the accessory drive belts. 3 Refer to Chapter 3 and remove the fan shroud and fan clutch assembly. 4 Remove the crankshaft damper bolt with a socket and large breaker bar (see illustration). To hold the crankshaft stationary, remove the flywheel inspection cover (see Chapter 8) and wedge a large screwdriver into the flywheel ring gear teeth.

Warning: The damper bolt is under considerable torque, so be sure the socket is firmly in place and that your hands are

not in danger of hitting anything sharp.

5 Use a bolt-type damper puller (available at most car accessory outlets) to remove the crankshaft damper (see illustration). 7 Remove the Woodruff key from the crankshaft keyway (see illustration). 8 Carefully pry the seal out of the front cover with a screwdriver or seal-removal tool (see illustration). Don’t scratch the bore or

Engine in-car repair procedures 2A•5

6.3 Remove nuts (small arrows) retaining the exhaust pipe to the manifold flanges;

two for each pipe - larger arrow indicates

one heat shield bolt accessible from below

6.4 Remove the upper heat shield bolts (arrowed)

6.6 Remove the bolts and nuts and remove the front and rear exhaust

manifolds

6.8 Refit new gaskets in position over the studs with the markings facing out

7.7 Carefully tap one end the Woodruff key up and out from the crankshaft keyway,

then grasp it with a pair of locking pliers

and pull it the rest of the way out - be

careful not to damage the key or keyway

7.8 Remove the crankshaft seal with a

screwdriver or seal puller - there are two

slots (arrowed) in the cover which allow

you to pry behind the seal

7.4 Use a large breaker bar and the

appropriate size socket to remove the

crankshaft pulley bolt

7.5 After removing the centre bolt, remove the crankshaft damper with a two-bolt

puller - be careful not to damage the

sensor ring

3261 Jaguar XJ6

damage the crankshaft in the process (if the crankshaft is damaged, the new seal will end up leaking). 9 The crankshaft seal rides on a spacer that slips over the front of the crankshaft. Slip the spacer off and clean the varnish off the seal surface (see illustration). 10 Clean the bore in the cover and coat the outer edge of the new seal with engine oil or multi-purpose grease. Apply moly-base grease to the seal lip. 11 Lubricate the spacer with clean engine oil and refit it onto the crankshaft. Using a socket with an outside diameter slightly smaller than the outside diameter of the seal, carefully drive the new seal into place with a hammer (see illustration). Make sure it’s installed squarely and driven in to the same depth as the original. If a socket isn’t available, a short section of large-diameter pipe will also work.

Note: The new seal comes with a plastic installer guide. Do not remove this guide until refitting is completed. The guide keeps the seal lip properly oriented over the crankshaft.

12 Refit the Woodruff key, then refit the damper. Tighten the damper bolt to the torque listed in this Chapter’s Specifications.

Note: The damper bolt can be used to pull the damper back onto the crankshaft, but make sure the damper is perfectly aligned with the Woodruff key.

13 The rest of the assembly is the reverse of the removal procedure. 14 Run the engine and check for oil leaks at the front seal.

8 Timing chains

and sprockets - removal,

inspection and refitting

Caution: If the timing chain broke during engine operation, the valves may have come in contact with the pistons, causing

damage. Check the valve clearance (see Section 10) before removal of the cylinder head - bent valves usually will have excessive clearance, indicating damage that will require machine workshop work to repair.

Note 1: This procedure requires that the sump be removed (see Section 12). In a professional workshop, this would be performed as an incar procedure with specialised tools to remove the front suspension. Given the equipment available to the average home mechanic, this alternate procedure requires removal of the engine from the car. Note 2: If your engine is a 4.0 litre, built after serial number 9J160552, and you’re experiencing an engine rattle on cold starts that disappears after the engine is warmed up, the problem could be a defective upper tensioner. A newly designed replacement upper tensioner is available from the dealer and should solve the problem. It can be installed easily without pulling the cylinder head or front cover, or can be installed during a chain removal procedure.

Removal

1 Disconnect the negative cable from the battery.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Block the rear wheels and set the handbrake. 3 Refer to Part B of this Chapter for engine removal procedures. 4 Refer to Section 4 and remove the valve cover. 5 Refer to Section 3 and position the engine at TDC for cylinder number 1, then mark and remove the distributor (see Chapter 5). 6 Refer to Section 11 and remove the cylinder head. After cylinder head removal, the upper

timing chain will be loosely retained by the two upper chain guides, which are retained by refitting a large rubber band (see Section 10).

Caution: Do not rotate the crankshaft with the upper timing chain disconnected and the cylinder head and camshafts in place, or damage could result from piston-tovalve contact.

7 Some models may be equipped with a hydraulic pump used for the brake servo/hydraulic self-levelling suspension system. If equipped, it will be mounted to the front cover. Models not equipped with this option will have a flat block-off plate over the hole. If equipped with the pump, refer to Chapters 9 and 10 for procedures to reduce the high pressure in the brake servo system and to depressurise the self-levelling system. Before removing the engine, unbolt the pump from the front cover and set it aside without disconnecting the hoses (see illustration). 8 Refer to Section 7 and remove the crankshaft pulley and damper. Refer to Section 12 for removal of the sump. 9 If equipped with the hydraulic pump, remove the coupling disc and unbolt the drive coupling from the intermediate shaft (see illustrations).

2A•6 Engine in-car repair procedures

8.7 Unbolt the hydraulic pump (arrowed) from the front cover, without

disconnecting the hoses

3261 Jaguar XJ6

7.9 Remove the spacer from the end of the crankshaft and clean it thoroughly

7.11 Drive the new seal squarely into the front cover with a large socket or section of pipe - do not remove the plastic refitting

guide (arrowed) until the seal is installed

10 Remove the front cover-to-engine block

bolts (see illustration). Note: Two of the front cover bolts are water pump assembly bolts. Refer to Chapter 3 for water pump removal, although only the two bolts that attach to the engine block need be removed.

11 Release the rubber band from the upper tensioners and remove the upper timing chain

(see illustration). 12 Remove the upper chain guides (see illustration). 13 Unbolt and remove the lower timing chain tensioner (see illustration). 14 Refer to Section 13 for removal of the oil

pump sprocket and drive chain. 15 Remove the lower timing chain from the

intermediate sprocket, auxiliary shaft sprocket and the crankshaft sprocket (see illustration). 16 Before proceeding any further, apply timing marks on the crankshaft and the engine block, allowing you to locate TDC position without the crankshaft pulley in place (see illustration).

Inspection

17 Examine the sprockets for signs of wear or damage. Renew the timing chain if obvious wear or damage is noted or if it is the least bit questionable. Note: If there is wear or damage

noticed in any of the sprockets or chains, the entire set must be renewed, i.e. new chains and new sprockets.

18 Correct any problems which contributed to chain failure prior to refitting of a new chain. 19 Check the chain guides for grooves, chips or wear in the contact surface. Clean and inspect the upper and lower tensioners.

Refitting

20 Remove all dirt, oil and grease from the timing chain area at the front of the engine. 21 Recheck the crankshaft timing marks to be sure they are properly aligned (see

illustration 8.16). 22 Refit the lower timing chain on the

crankshaft, intermediate-shaft and auxiliaryshaft sprockets. The chain should be lubricated with engine oil.

Engine in-car repair procedures 2A•7

8.9a Pull the hydraulic pump coupling disc (arrowed) off the drive coupling . . .

8.9b . . . and unbolt the drive coupling (arrowed) from the intermediate shaft

8.10 Remove the front cover-to-engine block and the sump-to-cover bolts

(arrowed)

8.11 Remove the upper timing chain from the intermediate sprocket (arrowed)

8.12 Unbolt and remove the upper chain guide (right arrow) and the upper chain

tensioner guide (left arrow)

8.13 Remove the two bolts and remove

the lower timing chain tensioner (arrowed)

3261 Jaguar XJ6

8.15 Remove the lower timing chain from

the intermediate sprocket (A), the auxiliary

shaft sprocket (B) and the crankshaft

sprocket (C)

8.16 Apply paint marks on the crankshaft, crankshaft sprocket and the engine block

(arrowed) to indicate TDC position

23 Clean and lubricate the lower tensioner.

Fill the lower tensioner oil reservoir with engine oil and refit it on the engine block, aligning the notch in the tensioner with the lug on the back of the guide (see illustrations). This should remove all slack from the lower timing chain. If not, push the lower tensioner guide back and forth a few times to prime the tensioner. 24 Refit the upper chain tensioner guide and mounting bracket to the engine block.

Caution: Before fully tightening the mounting bracket to the engine block, make sure the mount and chain guide are clear of the lower chain, auxiliary sprocket and intermediate sprocket. If necessary, position the mount for clearance before tightening the mounting bolts.

25 Refit the oil pump drive chain and sprocket to the crankshaft (see Section 13). 26 Refit the upper chain fixed guide to the engine block and place the upper timing chain over the intermediate sprocket and auxiliary shaft sprocket, draping the excess chain over the top of the fixed guide. Lubricate the chain and sprockets with clean engine oil.

27 Gather the loose portion of the upper timing chain and place it between the upper guides. Use a large rubber band to hold the two guides snugly around the chain (see

Section 11). 28 If necessary, renew the intermediate shaft seal (see illustrations). 29 Apply a thin coat of RTV sealant to the

engine side of the front cover and RTV sealant to the oil-pan mating surface (bottom of the front cover), then refit the front cover. Note:

Make sure the top surface of the cover aligns with the top surface of the engine block, by checking with a straightedge (see illustration).

30 Refer to Section 11 for refitting of the cylinder head and Section 10 for refitting of the camshafts and connection of the upper timing chain to the two camshaft sprockets. 31 The remainder of the refitting is the reverse of the removal procedure. If your car is equipped with the hydraulic/self-levelling suspension, refit the drive coupling and coupling disc to the intermediate shaft (see illustrations 8.9a and 8.9b). Coat the mounting surface of the pump with RTV

sealant and make sure the tang on the pump aligns with the slot in the intermediate shaft before bolting the pump to the front cover. Refer to Section 7 for refitting of the crankshaft spacer, damper and puller.

Caution: DO NOT start the engine until you’re absolutely certain that the timing chains are installed correctly. Serious and costly engine damage could occur if the chains are installed wrong.

32 Run the engine and check for proper operation.

9 Auxiliary shaft - renewal

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

1 Refer to Chapter 10 and remove the power steering pump, without disconnecting the hoses. Remove the plastic power steering pump drive coupling disc.

2A•8 Engine in-car repair procedures

8.28a Drill a small hole in the intermediate shaft seal, thread a sheet metal screw into

it and use a small slide-hammer pull the

seal out of the cover

8.28b Drive the new seal in with a seal-

driver or socket, to the same depth as the

original seal

8.29 Bolt the front cover on hand tight, use

a straightedge to make sure the cover’s

top surface is level with the top of the

engine block, then tighten the cover bolts

3261 Jaguar XJ6

8.23a Add oil to the reservoir in the lower tensioner . . .

8.23b . . . and refit the tensioner against the guide -

after it’s installed, push the tensioner guide back and forth

a few times to prime the tensioner

2 Refer to Section 8 and remove the front

cover and upper and lower timing chains. 3 Remove the power steering drive coupling from the auxiliary shaft (see illustration). 4 Use a small drill to drill holes in the oil seal, then use a slide-hammer puller to remove the seal from the rear of the auxiliary shaft housing (see illustration).

Caution: Drill straight and carefully to avoid damaging the auxiliary shaft.

5 Use a pair of snap-ring pliers to remove the snap ring from the rear of the auxiliary shaft

(see illustration). 6 Pull the auxiliary shaft out toward the front

of the engine. 7 Remove the three internal hex-head bolts and the auxiliary shaft housing. 8 Examine the surface of the auxiliary shaft, it’s sprocket, and the distributor drive-gear. If there is noticeable wear or damage, replace the auxiliary shaft assembly with a new one

(see illustration). 9 If the auxiliary shaft housing has been

removed, clean it, scrape away the old gasket material from the housing and the engine block and refit the housing with a new gasket

(see illustration). 10 Clean the auxiliary shaft, lubricate it with

engine oil and refit it through the front of the block, then refit the washer (see illustration). Refit the snap-ring (refer to illustration 9.4).

11 The new oil seal for the rear of the auxiliary shaft comes with a plastic refitting sleeve that keeps the seal lip from folding back during refitting. Keep this sleeve in place until the seal is fully installed. Tap the new seal into the housing with a hammer and appropriate-size socket until the seal is flush, then remove the plastic sleeve (see illustration). 12 The remainder of the refitting is the reverse of removal. Note: When refitting the

distributor (see Chapter 5), use a new O-ring to prevent oil leaks at the distributor.

13 Run the engine and check for oil leaks at the power steering pump-to-housing interface.

10 Camshafts and valve lifters -

removal, inspection and refitting

Removal

Note: The renewal of the camshafts requires the use of several special tools. Read through the procedure and acquire the special tools, or their equivalent, before beginning work.

1 Remove the valve cover (see Section 4). 2 Refer to Section 3 and position the engine

at TDC for number 1 cylinder. 3 Refer to Chapter 5 and remove the distributor cap and set it aside along with the spark plug leads. Mark the positions of the distributor body and rotor. 4 Using a feeler gauge, measure and record the clearance between the intake and exhaust camshaft lobes and the lifters for cylinder number 1 (see illustration). Rotate the crankshaft until the next cylinder in the firing order is at TDC and check and record the valve clearance for that cylinder. Following the firing order, check and record the valve clearance for the remaining valves with the appropriate cylinder at TDC. 5 Return the engine to TDC for cylinder number 1. Using the special tool (Jaguar tool no. 18G 1433), check the position of each

Engine in-car repair procedures 2A•9

9.3 Use a screwdriver to hold the drive coupling (arrowed) stationary while

removing the bolt

9.4 Remove the auxiliary shaft seal with a small slide-hammer puller

9.5 Use snap-ring pliers to remove the

snap ring (arrowed) from the shaft - note

the three internal hex-head bolts retaining

the housing to the engine block

9.8 Inspect these areas of the auxiliary shaft for wear

A Oil seal surface B Bearing journal

C Sprocket D Distributor drive

9.9 Refit the auxiliary shaft rear housing with a new gasket, aligning the oil slot

(arrowed) with the housing

3261 Jaguar XJ6

9.10 Refit the washer before replacing the snap-ring

9.11 Tap the seal squarely into the bore with a socket until the seal is flush

with the housing, then remove the

plastic fitting sleeve

camshaft to ensure that they are truly at TDC (see illustration). It may be necessary to rotate the crankshaft slightly, to allow the tool to fit into the slot. Once the camshafts are positioned, DO NOT rotate the crankshaft further. 6 Check the TDC marks made on the distributor body and refer to Chapter 5 for removal of the distributor. Note: Plug the distributor hole with a rag to keep out dirt.

7 Locate the upper timing chain tensioner on the right front of the cylinder head. Loosen the bolt on the clamp and swing the clamp away from the tensioner return valve, then remove the valve (see illustration). 8 Remove the tensioner bolts and pull out the tensioner. 9 The camshaft bearing caps are each retained by three bolts (the two front caps on each camshaft have only two bolts), of which

one is a cylinder head bolt that threads into the engine block. If the camshafts are being removed as a step in cylinder head removal, the following steps involving spacer blocks are not required, just remove the bolts and caps, then remove the camshafts. If the procedure is being used for camshaft removal or adjustment of the lifter shims, the procedure must be followed exactly to maintain the cylinder head gasket seal. 10 To maintain a good seal on the cylinder head gasket, if the cylinder head is not being removed, a spacer block (Jaguar tool no. 18G 1435) is used to replace each camshaft bearing cap as it is removed. Begin by unbolting and removing intake cap no. 2. Remove the large cylinder head bolt first, then the cap bolts. Without delay, refit a spacer block, with the cylinder head bolt, and tighten it to 53 Nm (39 lbf ft) (see illustrations). 11 Repeat paragraph 10 with the remainder of the intake camshaft caps in sequence. After cap 5 in the sequence, loosen the front and rear caps alternately until valve spring pressure is relieved from the camshaft (see

illustrations). Note: No spacer blocks are required with the number 1 camshaft caps.

2A•10 Engine in-car repair procedures

10.7 Loosen this bolt (arrowed) and swing the clamp away from the tensioner, then

use pliers to pull the valve out

10.10a As each cap is removed . . . 10.10b . . . replace it with the special spacer block (arrowed) and tighten the

cylinder head bolt to 53 Nm (39 lbf ft)

3261 Jaguar XJ6

10.4 Measure the valve clearance with a feeler gauge inserted between the heel of the camshaft lobe and the lifter

10.5 Position the camshaft alignment tool over each camshaft - the projection on the tool only fits into the slot on the camshafts when

they are at TDC - flip the tool over to check the other camshaft

10.11a Each of the camshaft bearing caps are stamped with I (intake) or E (exhaust)

and a number (arrowed)

10.11b After cap no. 2 is replaced with a spacer, repeat the procedure for the other caps in the sequence shown - after cap 5, loosen caps 6 and 7 alternately until valve

spring pressure is relieved

12 Remove the four bolts in each camshaft

inner sprocket (see illustration). The bolts are secured by sheetmetal “washer” plates. Bend down the locking tabs with a hammer and screwdriver tip to remove the bolts.

Caution: Stuff rags below the sprockets while removing the bolts to prevent a bolt from falling down into the front cover.

13 Remove the two bolts retaining the upper chain guide to the cylinder head (see

illustration). 14 Pull the inner sprockets from each

camshaft (see illustration). Each camshaft sprocket is comprised of an inner and outer, each with a set of fine splines that lock them together. The outer sprockets, with the teeth, can rotate on the camshafts until the inner sprocket bolts are tightened. 15 Pull the outer sprockets from the camshafts and allow the chain slacken. 16 At this point the camshafts can be carefully lifted straight up and off the cylinder head. Take care not to nick any of the lobes or journals during removal. 17 Use a magnet to remove the lifters, keeping them in order in a divided, numbered box (see illustration). They must be returned to their original location if reusing the original camshafts! 18 Removing the lifters exposes the adjusting shims, sitting in a pocket in each

valve spring retainer (see illustration). Keep the shims with their matching lifters. Measure the thickness of each shim with a micrometer and record the measurements.

Inspection

19 After the camshaft has been removed from the engine, cleaned with solvent and dried, inspect the bearing journals for uneven wear, pitting and evidence of seizure. If the journals are damaged, the bearing surfaces in the cylinder head and caps may be damaged as well, requiring renewal of the cylinder head. 20 Measure the bearing journals with a micrometer to determine if they are excessively

worn or out-of-round (see illustration). Compare the measurements to Specifications. 21 Check the camshaft lobes for heat discolouration, score marks, chipped areas, pitting and uneven wear. Measure the lobe heights with a micrometer and record the measurements (see illustrations). If there is variance of more than 0.005-inch, the camshaft and lifters must be renewed. If the lobes are in good condition, the camshaft can be reused. 22 Inspect the top, bottom and side surfaces of the lifters for wear, grooving or scoring. If the lifters are damaged, the camshaft and its lifters must be renewed as a set.

Engine in-car repair procedures 2A•11

10.13 Remove the two bolts and the upper timing chain guide (arrowed)

10.14 Pull the inner sprocket from the outer sprocket of each camshaft

10.17 A magnet can be used to remove the lifters (arrowed)

10.18 The valve adjustment shims

(arrowed) fit into a pocket in the valve

spring retainer - use a magnet to remove

the shims and keep them with their

respective lifters

10.20 Measure the bearing journals with a micrometer to check diameter - measure

at several places around the journal to

check for taper or out-of-round

3261 Jaguar XJ6

10.12 Bend back the locking tabs

(arrowed) and remove the camshaft

sprocket bolts

10.21a Measure the camshaft lobe at its greatest dimension . . .

10.21b . . . and subtract the camshaft lobe diameter at its smallest dimension to

obtain the lobe lift

Refitting

23 If the valve clearance for any valve is incorrect, as measured in paragraph 4, refit a thicker or thinner shim on that valve. For example, if the clearance had been too large by 0.004-inch (compared to the recommended clearance in the Specifications), replace the existing shim there with a new one that is

0.004-inch thicker. If the clearance was too small, use a shim that is smaller than the original. Shims are identified alphabetically, in sizes from 0.085-inch (designated size A, the smallest) to 0.108-inch (designated size X, the thickest). 24 Lubricate the lifters with a thin coat of moly-based lubricant on the top, bottom and sides and refit them in their original positions. 25 Lubricate the camshafts with moly-based grease on the journals and lobes and lay them carefully in their bearing saddles. 26 Using NEW cylinder head bolts, replace the spacers, one at a time, with the bearing caps and bolts. Tighten the cap bolts, then the cylinder head bolts to the torque listed in this Chapter’s Specifications. The front cap

should be installed first, then cap number 7, then alternately tighten the first and last caps to bring the camshaft down evenly. Next refit caps 4, 2, 3, 5, and 6. 27 Align the intake camshaft with the special camshaft positioning tool as described in paragraph 5. Engage the outer sprocket with the chain, slip the sprocket over the end of the camshaft, then turn it until there is no slack in the chain to the right of the camshaft sprocket (facing the front of the engine). Now align the inner sprocket with the camshaft until the bolt holes align and mesh the splines between the two sprocket halves (see illustrations). Tighten the inner sprocket bolts to the camshaft and bend the locking sheetmetal tabs over the bolts. 28 Keeping the slack in the chain to the left of the exhaust camshaft, refit the exhaust camshaft outer sprocket, meshed with the chain, over the end of the exhaust camshaft. Insert the timing chain tensioner tool (Jaguar tool no. 18G 1436) at the upper tensioner mounting point (see illustration). Note: The

chain tensioner tool applies pressure to the upper timing chain to simulate the effect of the

tensioner, which is operated by engine oil pressure when the engine is running.

29 Align the exhaust camshaft to TDC with the special timing gauge tool. Tighten the centre bolt in the tensioner tool to 4 to 6 Nm. When the chain is tensioned, align the inner exhaust sprocket with the bolt holes in the camshaft, engage the splines between the two sprocket halves and secure the sprocket with the bolts and locking tabs. Refit the clip to secure the two sprocket halves together. 30 Clean the tensioner gasket surface, fit a new gasket and O-rings, push the ratchet down and twist it to maintain the fully retracted position, and refit the tensioner in place of the tensioning tool (see illustration).

Note: Align the slot in the end of the tensioner straight up and down to fit over the tang on the back of the chain tensioner guide.

31 Rotate the engine and recheck that all valve clearance measurements are now correct (see paragraph 4). 32 The remainder of refitting is the reverse of the removal procedure. Note: When refitting

the distributor, use a new O-ring where it fits into the engine block.

2A•12 Engine in-car repair procedures

3261 Jaguar XJ6

10.27a Each camshaft sprocket is comprised of two sections, an inner (A) and outer (B) that are splined together

10.27b Push the outer sprocket over the intake camshaft until it

locks in place - then turn the sprocket left to remove chain slack

at the right

10.28 The special tensioning tool simulates the operation of the oil-driven tensioner - apply 4 to 6 Nm (36 to 48 inch-pounds)

pressure on the centre bolt (arrowed)

10.30 Upper timing chain tension components

A Notch (to align

with tang on guide)

B Tensioner ratchet C O-ring

D Gasket E valve (with O-rings)

11 Cylinder head -

removal and refitting

Note: The engine must be completely cool before beginning this procedure.

Removal

1 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Drain the coolant from the engine block and radiator (see Chapter 1). 3 Drain the engine oil and remove the oil filter (see Chapter 1). 4 Remove the bonnet for easier access, if necessary (see Chapter 11).

5 Remove the intake manifold (see Section 5). 6 Remove the exhaust manifolds (Section 6). 7 Remove the valve cover (see Section 4). 8 Refer to Section 3 and Position the engine

at TDC for cylinder number 1. Remove the distributor (see Chapter 5). 9 Remove the camshafts and sprockets (see Section 10). Place the upper chain between the two upper chain guides and wrap a large rubber band around the two guides, retaining the chain and guides. 10 Remove the coolant housing from the cylinder head (see illustration). 11 Remove the cylinder head-to-front cover bolts (see illustration). 12 Using a socket and breaker bar, loosen the cylinder head bolts in quarter-turn increments until they can be removed by hand. Loosen the cylinder head bolts using the opposite of the recommended tightening sequence (see illustration 11.23) to avoid warping or cracking the cylinder head. 13 Lift the cylinder head off the engine block. If it’s stuck, very carefully pry up at the transmission end, beyond the gasket surface.

Caution: Though the cylinder head is aluminium, it is still heavy, large and

awkward to handle. To avoid damaging the body during removal, use an engine hoist to lift the cylinder head out of the engine compartment, or have an assistant help you.

14 With the cylinder head on a workbench, remove all external components from the cylinder head to allow for thorough cleaning and inspection. See Chapter 2, Part B, for cylinder head servicing procedures.

Refitting

15 The mating surfaces of the cylinder head and engine block must be perfectly clean when the cylinder head is installed. 16 Use a gasket scraper to remove all traces of carbon and old gasket material, then clean the mating surfaces with lacquer thinner or acetone. If there’s oil on the mating surfaces when the cylinder head is installed, the gasket may not seal correctly and leaks could develop. When working on the engine block, stuff the cylinders with clean workshop rags to keep out debris. Use a vacuum cleaner to remove material that falls into the cylinders.

Caution: Use care when cleaning the cylinder head gasket surface. The cylinder head and engine block are aluminium and can be easily damaged by using sharp

scraping tools. Gasket removal solvents are available from car accessory outlets and may be useful for safe removal of gasket material.

17 Check the engine block and cylinder head mating surface for nicks, deep scratches and damage from coolant corrosion. If damage is slight, it can be removed with a file; if it’s excessive, machining may be the only alternative. See Part B of this Chapter for procedures and criteria concerning the repair of corrosion damage. 18 Use a tap of the correct size to chase the threads in the cylinder head bolt holes, then clean the holes with compressed air - make sure that nothing remains in the holes.

Warning: Wear eye protection when using compressed air!

19 Remove the rear cover from the cylinder head. Clean the gasket surface and refit the cover with a new gasket (see illustration). Place the side of the gasket with the sealer bead against the cylinder head, do not use sealant on this gasket. 20 Fabricate two alignment studs from the old head bolts. Cut off the heads, then slot the ends with a hacksaw (see illustration). New cylinder head bolts must be used when refitting the head.

Engine in-car repair procedures 2A•13

11.19 Remove the rear cover from the

cylinder head, clean the gasket surfaces

and refit the cover with a new gasket

(arrowed) - note that the printed-on sealer

bead is placed against the cylinder head

11.20 Fabricate two alignment studs from old cylinder head bolts and refit them in

the engine block - after the cylinder head

is installed, remove the two studs

3261 Jaguar XJ6

11.10 Disconnect the hoses and remove the bolts to separate the coolant housing (arrowed) from the cylinder head

11.11 Remove the bolts (arrowed) securing the cylinder head to the front cover

21 There are variations in cooling holes in

some models. Before refitting the cylinder head gasket, carefully check all of the passages and bolt holes in the new cylinder head gasket to be sure it matches your engine block. Also make sure the new cylinder head gasket you’re using is equipped with the improved oil transfer hole seal (see illustration). Position the cylinder head gasket over the dowel pins in the engine block, make sure TOP is facing up (see illustration). 22 Carefully place the cylinder head on the engine block without disturbing the gasket. 23 Refit NEW cylinder head bolts and following the recommended sequence, tighten the bolts in two steps to the torque listed in this Chapter’s Specifications (see illustration). Step 2 of the tightening sequence requires the bolts to be tightened and additional 90°. An angle-torque attachment for your torque wrench is available at car accessory outlets. This tool provides precision when the angle-torque method is required and its use is highly recommended. If the tool is not available, paint a mark on the edge of each cylinder head bolt and tighten the bolt until the mark is 90¡ from the starting

point. After the cylinder head bolts are tightened, tighten the cylinder head-to-timingcover bolts. 24 The remaining refitting steps are the reverse of removal. Refer to Section 10 for replacing the camshaft sprockets and adjusting the timing chain and tensioner. Refill the cooling system (see Chapter 1). 25 Run the engine and check for oil or coolant leaks. Adjust the ignition timing (see Chapter 5) and road test the car.

12 Sump - removal and refitting

Removal

1 Note: The sump cannot be removed with the engine in the chassis without lowering the front suspension and crossmember. This is a difficult procedure for the home mechanic without a vehicle hoist and some other specialised tools. The other alternative requires the engine be removed from the car and mounted on a stand, as we have

illustrated here. Refer to Part B of this Chapter for engine removal procedures.

2 Drain the engine oil and remove the oil filter (see Chapter 1).

3 Remove the bolts and detach the sump (see illustration). 4 If it’s stuck, pry it loose very carefully with a small screwdriver or putty knife (see illustration). Don’t damage the mating

surfaces of the pan and engine block or oil leaks could develop.

2A•14 Engine in-car repair procedures

3261 Jaguar XJ6

11.21a Only use a head gasket with the improved oil transfer seal (right arrow) - the older style (left arrow) is prone to oil leaks

11.21b Place the new head gasket over the dowels in the engine block - note the markings for UP or TOP printed on the gasket

11.23 Cylinder head bolt TIGHTENING sequence 12.3 Remove the sump bolts (arrowed)

12.4 Pry at the recess in the front of the sump to break the gasket seal - insert a

putty knife, if necessary, between the

sump and engine block

Refitting

5 Remove all traces of old gasket material and sealant from the engine block and sump. Clean the mating surface with lacquer thinner or acetone.

Caution: Do not use a sharp scraping tool. Both the sump and the engine block are aluminium and could be easily damaged.

6 Make sure the threaded bolt holes in the engine block and bellhousing are clean. 7 Inspect the flange of the sump for any cracks, pits or scratches that could cause an oil leak. 8 Remove the baffle plate at the rear of the sump (see illustration). Clean the sump area and the baffle, then refit the baffle. 9 Inspect the oil pump pickup tube for cracks, or foreign material blocking the screen

(see illustration). 10 Apply a bead of RTV sealant to the sump

flange (see illustration). Note: The sump must be installed within 5 minutes of sealer application.

11 Carefully position the sump on the engine block and push it toward the transmission adapter plate as you press it against the engine block. Loosely refit four bolts, two on each side of the sump. Tighten the four bolts in a criss-cross pattern to the torque listed in this Chapter’s Specifications, then loosen each bolt 90°. 12 Refit the two engine adapter-to-sump bolts. Tighten the two bolts to the torque listed in this Chapter’s Specifications, then loosen each one 180°. 13 Refit the remainder of the sump-to-engine block bolts hand tight until all are installed, then tighten them to the torque listed in this Chapter’s Specifications. Lastly, tighten the two adapter-to-sump bolts to the torque listed in this Chapter’s Specifications.

Caution: Failure to follow this tightening procedure could stress or possibly crack the adapter plate.

14 The remainder of refitting is the reverse of removal. Be sure to add oil and refit a new oil filter. 15 Run the engine and check for oil pressure and leaks.

13 Oil pump - removal,

inspection and refitting

Removal

1 Remove the sump (see Section 12). 2 Unbolt the oil pickup tube and oil transfer housing from the engine block (see illustration). Note: Have a drain pan under the

transfer housing, as oil may drip out when the housing is loosened from the engine block.

3 Carefully pull the transfer housing and transfer tubes to the rear to separate them from the oil pump body. 4 Bend back the locking tabs and remove the

three bolts retaining the oil pump drive sprocket to the oil pump (see illustration). Pull the chain and sprocket from the front of the pump. Note: There are shims between the

sprocket and the pump. Collect them while pulling off the sprocket.

5 Remove the bolts and detach the oil pump from the engine. 6 Remove all traces of sealant and old gasket material from the oil pump body and engine block, then clean the mating surfaces with lacquer thinner or acetone. 7 Remove the screws and separate the front and rear pump covers from the body. Lift out the drive and driven rotors (see illustrations).

Note: Mark the front face of each rotor before removing them.

Engine in-car repair procedures 2A•15

12.8 Remove the bolts (arrowed) and the sheetmetal baffle plate - clean the sump

area of the sump with the baffle removed

12.9 Lubrication system components

A Oil pump B Transfer tubes

C Transfer housing D Oil pump pickup

12.10 Apply a bead of RTV sealant around the perimeter of the sump mounting

flange, be sure to run the bead around the

outside all bolt the holes

13.7a Remove the bolts and separate the front and rear pump covers

13.7b Remove the outer rotor (A) and inner rotor (B)

13.2 Unbolt the oil pump pickup (A) and the bolts (B) retaining the transfer

assembly (C) to the engine block

13.4 Pry back the locking tabs and remove the three bolts retaining the oil pump drive

sprocket to the pump

3261 Jaguar XJ6

Inspection

8 Clean and dry the pump body and both rotors. Measure the outside diameter of the outer rotor and thickness of both rotors. 9 Place the outer rotor into the pump body and use feeler gauges to measure the clearance between the outer rotor and the body (see illustration). 10 Place a straightedge across the pump body and measure between the straightedge and the rotors to check the over-the-rotor clearance (see illustration). Compare your measurements to this Chapter’s Specifications and renew the oil pump if any are beyond the maximum allowable. 11 Remove the oil pressure relief valve cap. Remove and clean the relief valve components

(see illustration). 12 Clean all components with solvent and

inspect them for wear and damage. If excessive wear, damage or if any clearance is beyond the Specifications, renew the entire pump as an assembly. 13 Check the oil pressure relief valve piston sliding surface and valve spring. If either the spring or the valve is damaged, they must be renewed as a set.

Refitting

14 Lubricate the drive and driven rotors with clean engine oil and place them in the case

with the marks facing out. Apply a thin coat of anaerobic sealant (Loctite 510 or 518) to the gasket flange and refit the cover (see

illustration). 15 Lubricate the oil pressure relief valve

piston with clean engine oil and refit the valve components into the oil pump body (see

illustration 13.11). 16 Apply a thin coat of anaerobic sealant

(Loctite 510 or 518) to the oil pump-to-engine block-mounting surface, position the oil pump body against the engine block and refit the mounting bolts, tightening the bolts to the torque listed in this Chapter’s Specifications. Follow a criss-cross pattern when tightening the bolts to avoid warping the oil pump body. 17 If using the original oil pump, refit the original sprocket shim pack (see illustration). If a new pump is installed, start off with a

0.38 mm (0.015-inch) thick shim pack, refit the drive sprocket and align the sprocket as follows. 18 Use a straightedge to check the alignment of the oil pump sprocket with the crankshaft sprocket (see illustration). If they are not aligned, increase or decrease the shim pack at the oil pump sprocket until alignment is correct, then secure the oil pump sprocket bolts by bending up the sheetmetal tabs. Note: You

may be able to use all or part of the original shim pack from the original oil pump (if a new pump is being fitted). If required, shims are

available in 0.127 mm (0.005 inch), 0.254 mm (0.010 inch) and 0.508 mm (0.020 inch) sizes.

19 Fit new O-rings to each end of the transfer tubes and refit the tubes into the transfer housing. Note: Use petroleum jelly to lubricate the O-rings. 20 Apply a thin coat of RTV sealant to the engine block-mounting surface of the transfer housing. Lift the transfer housing and tubes into place and push the front of the tubes in the back of the oil pump, until you can start the transfer housing-to-engine block bolts. Tighten the bolts to the torque listed in this Chapter’s Specifications. 21 Refit the remaining parts in the reverse order of removal. 22 Add oil, start the engine and check for oil pressure and leaks.

23 Recheck the engine oil level.

14 Driveplate -

removal and refitting

Removal

1 Raise the car and support it securely on axle stands, then refer to Chapter 7 and remove the transmission. If it’s leaking, now would be a very good time to renew the front pump seal/O-ring.

2A•16 Engine in-car repair procedures

13.9 Measure the outer rotor-to-body

clearance with feeler gauges (arrowed)

13.10 With a straightedge held tight to the

pump surface, measure the clearance over

the rotors with feeler gauges

13.11 Oil pressure relief valve components

A Relief valve cap B Tube

C Spring D Valve

13.14 Apply a thin coat anaerobic sealant (Loctite 510 or 518) to the pump cover

sealing surface

13.17 Refit the original shim pack

(arrowed) if the original pump is being

used - if a new pump is being installed,

refit a 0.38 mm (0.015-inch) shim pack

3261 Jaguar XJ6

13.18 Check the oil pump and crankshaft sprocket alignment with a straightedge -

add or subtract shims until the sprockets

are aligned for smooth chain operation

2 Use a centre punch or paint to make

alignment marks on the driveplate and crankshaft to ensure correct alignment during refitting (see illustration). 3 Remove the bolts that secure the driveplate to the crankshaft. If the crankshaft turns, wedge a screwdriver through a hole in the driveplate to keep it from turning (see

illustration). 4 Remove the driveplate from the crankshaft. A spacer is located behind the driveplate (see illustration). Pry it off and store it with the

driveplate.

Warning: The ring-gear teeth may be sharp, wear gloves to protect your hands when handling the driveplate.

Refitting

5 Clean the driveplate to remove grease and oil. Inspect the surface for cracks. Check for cracked and broken ring gear teeth. Note: If

there is any damage to the driveplate, replace the driveplate with a new driveplate, a new spacer and new bolts. Improved parts are available as a set from the dealer.

6 Clean and inspect the mating surfaces of the driveplate and the crankshaft. If the crankshaft rear seal is leaking, renew it before refitting the driveplate (see Section 15). 7 Position the driveplate against the crankshaft. Be sure to align the marks made during removal. Some models may have an alignment dowel or staggered bolt holes to ensure correct refitting. Before refitting the bolts, apply thread-locking compound to the bolt threads. 8 Wedge a screwdriver in the ring gear teeth to keep the driveplate from turning and tighten the bolts to the torque listed in this Chapter’s Specifications. Follow a criss-cross pattern and work up to the final torque in three or four steps. 9 The remainder of refitting is the reverse of the removal procedure.

15 Crankshaft rear oil seal -

renewal

1 The transmission adapter plate and driveplate must be removed from the car for this procedure (see Chapter 7). 2 Remove the bolts, and detach the oil seal retainer. Remove the gasket material from the block and the seal retainer (see illustration). 3 Position the oil seal and retainer assembly between two wood blocks on a workbench and drive the old seal out from the backside

(see illustration). 4 The new seal must be driven into the

retainer plate from the engine side. Drive the

new seal into the retainer with a wood block or a section of pipe slightly smaller in diameter than the outside diameter of the seal (see illustration). The seal should be driven in only until it is flush with the transmission side of the retainer.

Caution: The new seal comes with a special plastic refitting sleeve inserted in the seal. It is designed to allow the seal to slide over the end of the crankshaft without displacing the seal lip. Do NOT remove this plastic sleeve until the retainer and seal have been installed on the engine.

5 Lubricate the seal area of the crankshaft with engine oil. Apply a bead of RTV sealant to the sealing surface of the retainer (see illustration).

Engine in-car repair procedures 2A•17

14.2 Mark the driveplate and the

crankshaft so they can be reassembled in

the same relative position

14.3 Use a screwdriver to secure the flywheel while the bolts are removed

14.4 Pry off the driveplate spacer - if a

driveplate is replaced, the spacer should

be replaced also

15.2 Remove the bolts (arrowed) and the crankshaft rear oil seal retainer from the

back of the engine block

15.3 After removing the retainer assembly from the engine block, support it between

two wood blocks and drive out the old seal

with a drift punch and hammer

15.4 Drive the new seal into the retainer with a wood block

3261 Jaguar XJ6

15.5 Apply RTV sealant to the sealing surface

6 Slowly and carefully press the seal and retainer squarely onto the crankshaft (see illustration). The plastic sleeve may be

pushed out as the retainer seats on the engine block. Remove the plastic sleeve. 7 Refit and tighten the retainer bolts to the torque listed in this Chapter’s Specifications. 8 The remaining steps are the reverse of removal.

16 Engine mounts -

check and renewal

1 Engine mounts seldom require attention, but broken or deteriorated mounts should be renewed immediately or the added strain placed on the driveline components may cause damage or wear.

Check

2 During the check, the engine must be raised to remove the weight from the mounts.

3 Raise the car and support it securely on axle stands, then position a jack under the engine sump. Place a large wood block between the jack head and the sump, then carefully raise the engine just enough to take the weight off the mounts. Do not position the wood block under the drain plug.

Warning: DO NOT place any part of your body under the engine when it’s supported by a jack!

4 Check the front mounts to see if the rubber is cracked, hardened or separated from the metal plates. Sometimes the rubber will split down the centre. 5 Check for relative movement between the mount plates and the engine or frame (use a large screwdriver or pry bar to attempt to move the mounts). If movement is noted, lower the engine and tighten the mount fasteners. 6 Rubber preservative should be applied to the mounts to slow deterioration.

Renewal

7 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

8 Raise the car and support it securely on axle stands. Support the engine as described in paragraph 3.

Caution: Ensure the cooling fan doesn’t hit the shroud as the engine is raised.

9 To remove either engine mount, remove the nut from the engine bracket, then raise the engine (see illustration). 10 From underneath the car, lower the steering gear (see Chapter 10) for access to the nut retaining the insulator to the chassis bracket. 11 Refitting is the reverse of removal. Use thread-locking compound on the mount bolts/nuts and be sure to tighten them securely. 12 See Chapter 7 for transmission mount renewal.

2A•18 Engine in-car repair procedures

3261 Jaguar XJ6

15.6 Refit the retainer and oil seal onto the crankshaft

16.9 Front engine mount (A)

and retaining nut to engine bracket (B)

3261 Jaguar XJ6

Chapter 2 Part B

Engine removal and overhaul procedures

General

Cylinder compression pressure @ 300 rpm, warm

Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6 to 11.3 bar (150 to 160 psi)

High compression models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 to 12.1 bar (160 to 170 psi)

Maximum variation between cylinders . . . . . . . . . . . . . . . . . . . . . . . . 0.8 bar (10 psi)

Oil pressure (engine warm)

At idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 bar (30 psi) minimum

At 4000 rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 bar (70 psi) minimum

Cylinder head

Resurfacing limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 mm (0.010 inch) maximum

Minimum thickness (see text)

3.6 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129.6 mm (5.101 inches)

3.2 and 4.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129.7 mm (5.108 inches)

Valves and related components

Valve stem-to-guide clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.038 to 0.076 mm (0.0015 to 0.0030 inch)

Valve springs, free length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40.13 mm (1.580 inches)

Valve lifter

Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.34 to 33.35 mm (1.3126 to 1.3130 inches)

Lifter-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 to 0.05 mm (0.0008 to 0.0020 inch)

Crankshaft and connecting rods

Connecting rod journal

Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.97 to 52.99 mm (2.0856 to 2.0861 inches)

Taper and out-of-round limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.008 mm (0.0003 inch) maximum

Bearing oil clearance

3.6 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.083 mm (0.0016 to 0.0033 inch)

3.2 and 4.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 to 0.0068 mm (0.0010 to 0.0027 inch)

Connecting rod side clearance (endplay) . . . . . . . . . . . . . . . . . . . . . . . . 0.127 to 0.228 mm (0.005 to 0.009 inch)

Main bearing journal

Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.217 to 76.233 mm (3.0007 to 3.0012 inches)

Taper and out-of-round limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.008 mm (0.0003 inch) maximum

Bearing oil clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.083 mm (0.0016 to 0.0033 inch)

Crankshaft endplay (standard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.101 to 0.254 mm (0.004 to 0.010 inch)

CHECK ENGINE light . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6

Crankshaft - inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Crankshaft - refitting and main bearing oil clearance check . . . . . . . 23

Crankshaft - removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Cylinder head - cleaning and inspection . . . . . . . . . . . . . . . . . . . . . . 10

Cylinder head - dismantling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Cylinder head - reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Cylinder compression check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Cylinder honing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Engine block - cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Engine block - inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Engine overhaul - dismantling sequence . . . . . . . . . . . . . . . . . . . . . . 8

Engine overhaul - general information . . . . . . . . . . . . . . . . . . . . . . . . 2

Engine overhaul - reassembly sequence . . . . . . . . . . . . . . . . . . . . . . 21

Engine rebuilding alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Engine - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Engine removal - methods and precautions . . . . . . . . . . . . . . . . . . . 5

General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Initial start-up and running-in after overhaul . . . . . . . . . . . . . . . . . . . 26

Main and connecting big-end bearings - inspection and selection . 20

Pistons/connecting rods - inspection . . . . . . . . . . . . . . . . . . . . . . . . 18

Pistons/connecting rods - refitting and big-end bearing

oil clearance check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Pistons/connecting rods - removal . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Piston rings - refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Rear main oil seal refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Vacuum gauge diagnostic checks . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Valves - servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2B•1

Specifications

Contents

Easy, suitable for

novice with little experience

Fairly easy, suitable for beginner with some experience

Fairly difficult,

suitable for competent DIY mechanic

Difficult, suitable for experienced DIY mechanic

Very difficult,

suitable for expert DIY or professional

Degrees of difficulty

Engine block

Deck warpage limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.076 mm (0.003 inch)

Cylinder bore diameter

Standard

Size group A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90.990 to 91.003 mm (3.5823 to 3.5828 inches)

Size group B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.005 to 91.018 mm (3.5829 to 3.5834 inches)

Oversize

0.25 mm (0.010 inch) OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.259 to 91.272 mm (3.5929 to 3.5934 inches)

0.50 mm (0.020 inch) OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.513 to 91.526 mm (3.6029 to 3.6034 inches)

Pistons and rings

Piston-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.017 to 0.043 mm (0.0007 to 0.0017 inch)

Piston ring end gap

No.1 (top) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 to 0.66 mm (0.016 to 0.026 inch)

No.2 (middle) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 to 0.66 mm (0.016 to 0.026 inch)

Oil ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 to 0.55 mm (0.012 to 0.022 inch)

Piston ring groove clearance

No. 1 (top) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.076 mm (0.0016 to 0.0030 inch)

No. 2 (middle) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.076 mm (0.0016 to 0.0030 inch)

Torque wrench settings Nm lbf ft

Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 to 142 100 to 105

Connecting rod cap nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 to 60 37 to 44

* Note: Refer to Part A for additional torque specifications.

2B•2 Engine removal and overhaul procedures

3261 Jaguar XJ6

1 General information

Included in this portion of Chapter 2 are the general overhaul procedures for the cylinder head and internal engine components.

The information ranges from advice concerning preparation for an overhaul and the purchase of replacement parts to detailed, step-by-step procedures covering removal and refitting of internal engine components and the inspection of parts.

The following Sections have been written based on the assumption that the engine has been removed from the vehicle. For information concerning in-vehicle engine repair, as well as removal and refitting of the external components necessary for the overhaul, see Part A of this Chapter.

The Specifications included in this Part are only those necessary for the inspection and overhaul procedures which follow. Refer to Part A for additional Specifications.

2 Engine overhaul -

general information

It’s not always easy to determine when, or if, an engine should be completely overhauled, as a number of factors must be considered.

High mileage is not necessarily an indication that an overhaul is needed, while low mileage doesn’t preclude the need for an overhaul. Frequency of servicing is probably the most important consideration. An engine that’s had regular and frequent oil and filter changes, as well as other required maintenance, will most likely give many thousands of miles of reliable

service. Conversely, a neglected engine may require an overhaul very early in its life.

Excessive oil consumption is an indication that piston rings, valve seals and/or valve guides are in need of attention. Make sure that oil leaks aren’t responsible before deciding that the rings and/or guides are bad. Perform a cylinder compression check to determine the extent of the work required (see Section 4). Also check the vacuum readings under various conditions (see Section 3).

Check the oil pressure with a gauge installed in place of the oil pressure sender unit (see illustrations) and compare it to this Chapter’s Specifications. If it’s extremely low, the bearings and/or oil pump are probably worn out.

Loss of power, rough running, knocking or metallic engine noises, excessive valve train noise and high fuel consumption rates may also point to the need for an overhaul, especially if they’re all present at the same time. If a complete tune-up doesn’t remedy the situation, major mechanical work is the only solution.

An engine overhaul involves restoring the internal parts to the specifications of a new engine. During an overhaul, the piston rings are replaced and the cylinder walls are reconditioned (rebored and/or honed). If a rebore is done by an automotive machine workshop, new oversize pistons will also be installed. The main bearings, big-end bearings and camshaft bearings are generally replaced with new ones and, if necessary, the crankshaft may be reground to restore the journals. Generally, the valves are serviced as well, since they’re usually in less-than-perfect condition at this point. While the engine is being overhauled, other components, such as the distributor, starter and alternator, can be rebuilt as well. The end result should be a like new engine that will give many trouble free miles. Note: Critical cooling system

components such as the hoses, drivebelts, thermostat and water pump should be replaced with new parts when an engine is overhauled. The radiator should be checked carefully to ensure that it isn’t clogged or leaking (see Chapter 3). If you purchase a

2.4a The oil pressure sender unit (arrowed) is located in the right front corner of the

engine block, near the oil filter

2.4b The oil pressure can be checked by removing the sender unit and refitting a

pressure gauge in its place

rebuilt engine or short block, some rebuilders will not warranty their engines unless the radiator has been professionally flushed. Also, we don’t recommend overhauling the oil pump - always refit a new one when an engine is rebuilt.

Before beginning the engine overhaul, read through the entire procedure to familiarise yourself with the scope and requirements of the job. Overhauling an engine isn’t difficult, but it is time-consuming. Plan on the vehicle being tied up for a minimum of two weeks, especially if parts must be taken to an automotive machine workshop for repair or reconditioning. Check on availability of parts and make sure that any necessary special tools and equipment are obtained in advance. Most work can be done with typical hand tools, although a number of precision measuring tools are required for inspecting parts to determine if they must be renewed. Often an automotive machine workshop will handle the inspection of parts and offer advice concerning reconditioning and renewal. Note: Always wait until the engine

has been completely dismantled and all components, especially the engine block, have been inspected before deciding what service and repair operations must be performed by an automotive machine workshop. Since the engine block’s condition

will be the major factor to consider when determining whether to overhaul the original engine or buy a rebuilt one, never purchase parts or have machine work done on other components until the engine block has been thoroughly inspected. As a general rule, time is the primary cost of an overhaul, so it doesn’t pay to refit worn or substandard parts.

If it turns out that a number of major components are beyond reconditioning, it may be cost effective to buy a factory-rebuilt engine from a Jaguar dealership.

As a final note, to ensure maximum life and minimum trouble from a rebuilt engine, everything must be assembled with care in a spotlessly-clean environment.

3 Vacuum gauge

diagnostic checks

A vacuum gauge provides valuable information about what is going on in the engine at a low cost. You can check for worn rings or cylinder walls, leaking cylinder head or intake manifold gaskets, incorrect carburettor adjustments, restricted exhaust, stuck or burned valves, weak valve springs, improper ignition or valve timing and ignition problems.

Unfortunately, vacuum gauge readings are easy to misinterpret, so they should be used with other tests to confirm the diagnosis.

Both the absolute readings and the rate of needle movement are important for accurate interpretation. Most gauges measure vacuum

in inches of mercury (in-Hg). As vacuum increases (or atmospheric pressure decreases), the reading will decrease. Also, for every 1000 foot increase in elevation above sea level; the gauge readings will decrease about one inch of mercury.

Connect the vacuum gauge directly to intake manifold vacuum, not to ported (above the throttle plate) vacuum (see illustration). Be sure no hoses are left disconnected during the test or false readings will result.

Before you begin the test, allow the engine to warm up completely. Block the wheels and set the handbrake. With the transmission in Park, start the engine and allow it to run at normal idle speed.

Warning: Carefully inspect the fan blades for cracks or damage before starting the engine. Keep

your hands and the vacuum tester clear of the fan and do not stand in front of the vehicle or in line with the fan when the engine is running.

Read the vacuum gauge; an average, healthy engine should normally produce between 17 and 22 inches of vacuum with a fairly steady needle.

Refer to the following vacuum gauge readings and what they indicate about the engines condition: 1 A low steady reading usually indicates a leaking gasket between the intake manifold and carburettor or throttle body, a leaky vacuum hose, late ignition timing or incorrect camshaft timing. Check ignition timing with a timing light and eliminate all other possible causes, utilising the tests provided in this Chapter before you remove the timing belt cover to check the timing marks. 2 If the reading is three to eight inches below normal and it fluctuates at that low reading, suspect an intake manifold gasket leak at an intake port or a faulty injector. 3 If the needle has regular drops of about two to four inches at a steady rate the valves are probably leaking. Perform a compression or leak-down test to confirm this. 4 An irregular drop or down-flick of the needle can be caused by a sticking valve or an ignition misfire. Perform a compression or leak-down test and read the spark plugs.

5 A rapid vibration of about four in-Hg vibration at idle combined with exhaust smoke indicates worn valve guides. Perform a leak-down test to confirm this. If the rapid vibration occurs with an increase in engine speed, check for a leaking intake manifold gasket or cylinder head gasket, weak valve springs, burned valves or ignition misfire. 6 A slight fluctuation, say one inch up and down, may mean ignition problems. Check all the usual tune-up items and, if necessary, run the engine on an ignition analyser. 7 If there is a large fluctuation, perform a compression or leak-down test to look for a weak or dead cylinder or a blown cylinder head gasket. 8 If the needle moves slowly through a wide range, check for a clogged PCV system, incorrect idle fuel mixture, throttle body or intake manifold gasket leaks. 9 Check for a slow return after revving the engine by quickly snapping the throttle open until the engine reaches about 2,500 rpm and let it shut. Normally the reading should drop to near zero, rise above normal idle reading (about 5 in.-Hg over) and then return to the previous idle reading. If the vacuum returns slowly and doesn’t peak when the throttle is snapped shut, the rings may be worn. If there is a long delay, look for a restricted exhaust system (often the silencer or catalytic converter). An easy way to check this is to temporarily disconnect the exhaust ahead of the suspected part and redo the test.

4 Cylinder compression check

1 A compression check will tell you what mechanical condition the upper end (pistons, rings, valves, cylinder head gasket) of your engine is in. Specifically, it can tell you if the compression is down due to leakage caused by worn piston rings, defective valves and seats or a blown cylinder head gasket. Note:

The engine must be at normal operating temperature and the battery must be fully charged for this check.

2 Begin by cleaning the area around the spark plugs before you remove them (compressed air should be used, if available, otherwise a small brush or even a bicycle tyre pump will work). The idea is to prevent dirt from getting into the cylinders as the compression check is being done. 3 Remove all of the spark plugs from the engine (see Chapter 1).

4 Block the throttle wide open. 5 Detach the coil wire from the centre of the

distributor cap and ground it on the engine block. Use a jumper wire with alligator clips on each end to ensure a good earth. Also, remove the fuel pump relay (see Chapter 4) to disable the fuel pump during the compression test.

Engine removal and overhaul procedures 2B•3

3.4 The vacuum gauge is easily attached to a port on the intake manifold, and can

tell a lot about an engine’s state of tune

3261 Jaguar XJ6

6 Refit the compression gauge in the spark plug hole (see illustration). 7 Crank the engine over at least seven compression strokes and watch the gauge. The compression should build up quickly in a healthy engine. Low compression on the first stroke, followed by gradually increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which doesn’t build up during successive strokes, indicates leaking valves or a blown cylinder head gasket (a cracked cylinder head could also be the cause). Deposits on the undersides of the valve heads can also cause low compression. Record the highest gauge reading obtained. 8 Repeat the procedure for the remaining cylinders and compare the results to this Chapter’s Specifications. 9 Add some engine oil (about three squirts from a plunger-type oil can) to each cylinder, through the spark plug hole, and repeat the test. 10 If the compression increases after the oil is added, the piston rings are definitely worn. If the compression doesn’t increase significantly, the leakage is occurring at the valves or cylinder head gasket. Leakage past the valves may be caused by burned valve seats and/or faces or warped, cracked or bent valves. 11 If two adjacent cylinders have equally low compression, there’s a strong possibility that the cylinder head gasket between them is blown. The appearance of coolant in the combustion chambers or the crankcase would verify this condition. 12 If one cylinder is 20 percent lower than the others, and the engine has a slightly rough idle, a worn exhaust lobe on the camshaft could be the cause. 13 If the compression is unusually high, the combustion chambers are probably coated with carbon deposits. If that’s the case, the cylinder head(s) should be removed and decarbonised. 14 If compression is way down or varies greatly between cylinders, it would be a good

idea to have a leak-down test performed by an automotive repair workshop. This test will pinpoint exactly where the leakage is occurring and how severe it is.

5 Engine removal -

methods and precautions

If you’ve decided that an engine must be removed for overhaul or major repair work, several preliminary steps should be taken.

Locating a suitable place to work is extremely important. Adequate work space, along with storage space for the vehicle, will be needed. If a workshop or garage isn’t available, at the very least a flat, level, clean work surface made of concrete or asphalt is required.

Cleaning the engine compartment and engine before beginning the removal procedure will help keep tools clean and organised.

An engine hoist or A-frame will also be necessary. Make sure the equipment is rated in excess of the combined weight of the engine and transmission. Safety is of primary importance, considering the potential hazards involved in lifting the engine out of the vehicle.

If the engine is being removed by a novice, a helper should be available. Advice and aid from someone more experienced would also be helpful. There are many instances when one person cannot simultaneously perform all of the operations required when lifting the engine out of the vehicle.

Plan the operation ahead of time. Arrange for or obtain all of the tools and equipment you’ll need prior to beginning the job. Some of the equipment necessary to perform engine removal and refitting safely and with relative ease are (in addition to an engine hoist) a heavy duty trolley jack, complete sets of spanners and sockets as described in the front of this manual, wooden blocks and plenty of rags and cleaning solvent for mopping up spilled oil, coolant and petrol. If the hoist must be rented, make sure that you arrange for it in advance and perform all of the operations possible without it beforehand. This will save you money and time.

Plan for the vehicle to be out of use for quite a while. A machine workshop will be required to perform some of the work which the do-it-yourselfer can’t accomplish without special equipment. These shops often have a busy schedule, so it would be a good idea to consult them before removing the engine in order to accurately estimate the amount of time required to rebuild or repair components that may need work.

Always be extremely careful when removing and refitting the engine. Serious injury can result from careless actions. Plan ahead, take your time and a job of this nature, although major, can be accomplished successfully.

6 Engine - removal and refitting

Note: Read through the entire Section before beginning this procedure. It is recommended to remove the engine and transmission from the top as a unit, then separate the engine from the transmission on the workshop floor. If the transmission is not being serviced, it is possible to leave the transmission in the vehicle and remove the engine from the top by itself, by removing the crankshaft damper and tilting up the front end of the engine for clearance, but access to the upper bellhousing bolts is only practical when the rear transmission mount and driveshaft have been removed and the transmission is angled down with a trolley jack.

Removal

1 Relieve the fuel system pressure (see Chapter 4). 2 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

3 Place protective covers on the wings and cowl and remove the bonnet (see Chapter 11).

4 Remove the battery and battery tray. 5 Remove the air cleaner assembly (see

Chapter 4). 6 Raise the vehicle and support it securely on axle stands. Drain the cooling system and engine oil and remove the drivebelts (see Chapter 1). 7 Clearly label, then disconnect all vacuum lines, coolant and emissions hoses, wiring harness connectors and earth straps. Masking tape and/or a touch up paint applicator work well for marking items (see illustration). Take instant photos or sketch the locations of components and brackets. 8 Remove the cooling fan(s) and radiator (see Chapter 3).

9 Disconnect the heater hoses. 10 Release the residual fuel pressure in the

tank by removing the petrol cap, then detach the fuel lines connecting the engine to the chassis (see Chapter 4). Plug or cap all open fittings.

2B•4 Engine removal and overhaul procedures

4.6 A compression gauge with a threaded fitting for the spark plug hole is preferred over the type that requires hand pressure

to maintain the seal - be sure to block

open the throttle valve as far as possible

during the compression check!

6.7 Label both ends of each wire and hose before disconnecting it

3261 Jaguar XJ6

11 Disconnect the throttle linkage, transmission linkage (and dipstick tube) and speed control cable, if equipped, from the engine (see Chapters 4 and 7). 12 Refer to Part A of this Chapter and remove the intake and exhaust manifolds. 13 Unbolt the power steering pump (see Chapter 10). Tie the pump aside without disconnecting the hoses. Refer to Part A for removal of the hydraulic pump (if equipped) from the timing chain cover. 14 On air-conditioned models, unbolt the compressor and set it aside. Do not disconnect the refrigerant hoses. Note: Wire

the compressor out of the way with a coat hanger, don’t let the compressor hang on the hoses.

15 Refer to Part A of this Chapter and remove the drivebelts, water pump pulley and crankshaft pulley. 16 Attach a lifting sling to the engine. Position a hoist and connect the sling to it. Take up the slack until there is slight tension on the hoist. 17 With a trolley jack and piece of wood supporting the bottom of the transmission sump, refer to Chapter 8 and remove the driveshaft and rear transmission mount.

Warning: Do not place any part of your body under the engine/transmission when it’s supported only by a hoist or other lifting device.

18 With the hoist taking the weight of the engine, unbolt the engine mounts (see Part A of this Chapter). 19 Recheck to be sure nothing is still connecting the engine or transmission to the vehicle. Disconnect and label anything still remaining. 20 Slowly lift the engine/transmission out of the vehicle (see illustration). It may be necessary to pry the mounts away from the frame brackets.

21 Move the engine away from the vehicle and carefully lower the hoist until the engine/transmission can be set on the floor. Refer to Chapter 7 and remove the transmission and converter. Refer to Part A of this Chapter for removal of the flywheel. With the flywheel removed, remove the four large bolts and the transmission adapter plate from the engine (see illustration). 22 Refer to Part A of this Chapter for removal of the rear main seal retainer plate from the back of the engine, then lift the engine to a position where it can be attached to a sturdy engine stand.

Refitting

23 Check the engine/transmission mounts. If they’re worn or damaged, renew them. 24 Attach the hoist and remove the engine from the stand. Refer to Part A of this Chapter and renew the rear main seal and retainer plate, then reattach the transmission adapter plate and refer to Chapter 7 for mounting the converter and transmission. 25 Carefully lower the engine into the vehicle with the hoist. An assistant is helpful to guide the engine clear of accessories in the engine compartment as the engine is lowered into place. 26 Refit the engine mount bolts and tighten them securely. Raise the back of the transmission with the trolley jack and reattach the transmission mount, driveshaft and shift linkage. 27 Refit the remaining components and fasteners in the reverse order of removal. 28 Add coolant, oil, power steering and transmission fluids as needed (see Chapter 1). 29 Run the engine and check for proper operation and leaks. Shut off the engine and recheck the fluid levels.

7 Engine rebuilding

alternatives

The do-it-yourselfer is faced with a number of options when performing an engine overhaul. The decision to renew the engine block, piston/connecting rod assemblies and crankshaft depends on a number of factors, with the number one consideration being the condition of the engine block. Other considerations are cost, access to machine workshop facilities, parts availability, time required to complete the project and the extent of prior mechanical experience on the part of the do-it-yourselfer.

Some of the rebuilding alternatives include:

Individual parts - If the inspection procedures reveal that the engine block and most engine components are in reusable condition, purchasing individual parts may be the most economical alternative. The engine block, cylinder head, crankshaft, and piston/connecting rod assemblies should all be inspected carefully. Even if the engine block shows little wear, the cylinder bores should be surface honed.

Short block - A short block consists of an engine block with a crankshaft and piston/connecting rod assemblies already installed. All new bearings are incorporated and all clearances will be correct. The existing camshafts, valve train components, cylinder head and external parts can be bolted to the short block with little or no machine workshop work necessary.

Long block - A long block consists of a short block plus an oil pump, sump, cylinder head, valve cover, camshaft and valve train components, timing sprockets and chain or gears and timing cover. All components are installed with new bearings, seals and gaskets

Engine removal and overhaul procedures 2B•5

3261 Jaguar XJ6

6.20 Lift the engine high enough to clear the vehicle, tilting it up at the front to clear the front crossmember, then move it away

and lower the hoist

6.21 With the engine on the floor but still supported by the hoist, remove the four large bolts (arrowed) and pull off the

transmission adapter plate

incorporated throughout. The refitting of manifolds and external parts is all that’s necessary. Engines in this rebuilt form are available from Jaguar dealers, and some independent rebuilders.

Give careful thought to which alternative is best for you and discuss the situation with local automotive machine shops, auto parts dealers and experienced rebuilders before ordering or purchasing replacement parts.

8 Engine overhaul -

dismantling sequence

1 It’s much easier to dismantle and work on the engine if it’s mounted on a portable engine stand. A stand can often be rented quite cheaply from an equipment rental yard. Before the engine is mounted on a stand, the driveplate and rear oil seal retainer should be removed from the engine. 2 If a stand isn’t available, it’s possible to dismantle the engine with it blocked up on the floor. Be extra careful not to tip or drop the engine when working without a stand. 3 If you’re going to obtain a rebuilt engine, all external components must come off first, to be transferred to the replacement engine, just as they will if you’re doing a complete engine overhaul yourself. These include:

Alternator and brackets Emissions control components Distributor, spark plug leads and spark plugs Thermostat and housing cover Water pump EFI components Intake/exhaust manifolds Oil filter Engine mounts Driveplate Transmission adapter plate

Note: When removing the external components from the engine, pay close attention to details that may be helpful or important during refitting. Note the installed position of gaskets, seals, spacers, pins, brackets, washers, bolts and other small items.

4 If you’re obtaining a short block, which consists of the engine block, crankshaft, pistons and connecting rods all assembled, then the cylinder head, sump and oil pump will have to be removed as well from your engine so that your short-block can be turned in to the rebuilder as a core. See Engine rebuilding alternatives for additional information regarding the different possibilities to be considered. 5 If you’re planning a complete overhaul, the engine must be dismantled and the internal components removed in the following order:

Intake and exhaust manifolds Valve cover Upper timing chain and camshaft sprockets

Camshafts Timing chain cover Cylinder head Sump Oil pump Piston/connecting rod assemblies Crankshaft rear oil seal retainer Crankshaft and main bearings

6 Before beginning the dismantling and overhaul procedures, make sure the following items are available. Also, refer to Section 21 for a list of tools and materials needed for engine reassembly.

Common hand tools Small cardboard boxes or plastic bags for storing parts Gasket scraper Ridge reamer Micrometers Telescoping gauges Dial indicator set Valve spring compressor Cylinder surfacing hone Piston ring groove-cleaning tool Electric drill motor Tap and die set Wire brushes Oil gallery brushes Cleaning solvent

Special Jaguar tools

Engine lifting brackets (18G 1465) Timing damper simulator (18E 1436) Camshaft TDC tool (18G 1433)

9 Cylinder head - dismantling

Note: New and rebuilt cylinder heads are available from Jaguar and some independent rebuilders. Due to the fact that some specialised tools are necessary for the dismantling and inspection procedures, and replacement parts may not be readily available, it may be more practical and economical for the home mechanic to purchase a replacement cylinder head rather than taking the time to dismantle, inspect and recondition the original.

1 Cylinder head dismantling involves removal of the intake and exhaust valves and related components. It’s assumed that the lifters and camshafts have already been removed (see Part A as needed). 2 Before the valves are removed, arrange to label and store them, along with their related components, so they can be kept separate and reinstalled in the same valve guides they are removed from (see illustration). 3 Compress the springs on the first valve with a spring compressor and remove the keepers (see illustration). Carefully release the valve spring compressor and remove the retainer, the spring and the spring seat (if used). Note:

If your spring compressor does not have an end (such as the one shown) with cut-outs on the side, an adapter is available to use with a standard spring compressor.

Caution: Be very careful not to nick or otherwise damage the lifter bores when compressing the valve springs.

4 Pull the valve out of the cylinder head, then remove the oil seal from the guide. If the valve binds in the guide (won’t pull through), push it back into the cylinder head and deburr the area around the keeper groove with a fine file or whetstone. 5 Repeat the procedure for the remaining valves. Remember to keep all the parts for each valve together so they can be reinstalled in the same locations. 6 Once the valves and related components have been removed and stored in an organised manner, the cylinder head should be thoroughly cleaned and inspected. If a complete engine overhaul is being done, finish the engine dismantling procedures before beginning the cylinder head cleaning and inspection process.

10 Cylinder head -

cleaning and inspection

1 Thorough cleaning of the cylinder head(s) and related valve train components, followed by a detailed inspection, will enable you to decide how much valve service work must be

2B•6 Engine removal and overhaul procedures

9.2 A small plastic bag, with an appropriate label, can be used to store the valve train

components so they can be kept together

and reinstalled in the correct guide

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9.3 Compress the spring until the keepers can be removed with a small magnetic

screwdriver or needle-nose pliers - use a valve spring compressor with an adapter

(arrowed) to remove the keepers

done during the engine overhaul. Note: If the engine was severely overheated, the cylinder head is probably warped (see paragraph 12).

Cleaning

2 Scrape all traces of old gasket material and sealing compound off the cylinder head gasket, intake manifold and exhaust manifold sealing surfaces. Be very careful not to gouge the cylinder head. Special gasket-removal solvents that soften gaskets and make removal much easier are available at car accessory outlets. 3 Remove all built up scale from the coolant passages. 4 Run a stiff wire brush through the various holes to remove deposits that may have formed in them. If there are heavy deposits in the water passages, the bare head should be professionally cleaned at a machine workshop. 5 Run an appropriate-size tap into each of the threaded holes to remove corrosion and any thread sealant that may be present. If compressed air is available, use it to clear the holes of debris produced by this operation.

Warning: Wear eye protection when using compressed air!

6 Clean the exhaust and intake manifold stud threads with a wire brush. 7 Clean the cylinder head with solvent and dry it thoroughly. Compressed air will speed the drying process and ensure that all holes and recessed areas are clean. Note: Decarbonising

chemicals are available and may prove very useful when cleaning cylinder heads and valve train components. They are very caustic and should be used with caution. Be sure to follow the instructions on the container.

8 Clean the lifters with solvent and dry them

thoroughly. Compressed air will speed the drying process and can be used to clean out the oil passages. Don’t mix them up during cleaning - keep them in a box with numbered compartments. 9 Clean all the valve springs, spring seats, keepers and retainers with solvent and dry them thoroughly. Work on the components from one valve at a time to avoid mixing up the parts. 10 Scrape off any heavy deposits that may have formed on the valves, then use a motorised wire brush to remove deposits from the valve heads and stems. Again, make sure that the valves don’t get mixed up.

Inspection

Note: Be sure to perform all of the following inspection procedures before concluding that machine workshop work is required. Make a

list of the items that need attention. The inspection procedures for the lifters and camshafts, can be found in Part A.

Cylinder head

11 Inspect the cylinder head very carefully for

cracks, evidence of coolant leakage and other damage. If cracks are found, check with an automotive machine workshop concerning repair. If repair isn’t possible, a new cylinder head should be obtained. 12 A common problem on aluminium engines is erosion of the cylinder head or engine block coolant passages due to improper sealing. Using a new cylinder head gasket held against the cylinder head, trace the bolt holes and coolant passage outlines in pencil on the cylinder head. Use the gasket to trace the same on the top of the engine block (see illustration). If the top of the engine block has eroded outside of the pattern around the

water passages or cylinder head bolt holes, the engine block must be renewed; the manufacturer doesn’t recommend resurfacing it. If the cylinder head has eroded outside of the water passage holes but the erosion is away from the combustion chamber, the eroded area can be built up with metalimpregnated epoxy and machined flat again. 13 Using a straightedge and feeler gauge, check the cylinder head gasket mating surface (on the engine block and cylinder head) for warpage (see illustration). If the warpage exceeds the limit found in this Chapter’s Specifications, it can be resurfaced at an automotive machine workshop, but no more then 0.010-inch of material should be removed. If the cylinder head had been overheated, take it to the machinist for inspection before proceeding further. It’s possible that the overheating could have annealed (softened) the aluminium of the cylinder head, making it unsuitable for machine work. In this case, a new cylinder head is required.

Note 1: To check if a cylinder head has been machined previously, measure the height between the cylinder head gasket surface and the valve cover mounting surface with a large micrometer or vernier caliper and compare with Specifications. Note 2: Jaguar aluminium cylinder heads require precision machine work. It is best to find a machine workshop that has considerable experience in servicing Jaguar cylinder heads.

14 Examine the valve seats in each of the combustion chambers. If they’re pitted, cracked or burned, the cylinder head will require valve service that’s beyond the scope of the home mechanic.

Engine removal and overhaul procedures 2B•7

3261 Jaguar XJ6

10.12 Place the new head gasket on the engine block, and trace

around the water passages and bolt holes - make sure there is no

erosion of the aluminium beyond these lines

10.13 Check the cylinder head and engine block gasket surfaces for warpage by trying to slip a feeler gauge under a precision

straightedge (see the Specifications for the maximum warpage

allowed and use a feeler gauge of that thickness) - check both the

cylinder head and engine block (shown)

15 Check the valve stem-to-guide clearance

with a small hole gauge and micrometer, or a small dial bore gauge (see illustration). Also, check the valve stem deflection with a dial indicator attached securely to the cylinder head. The valve must be in the guide and approximately 1/16-inch off the seat. The total valve stem movement indicated by the gauge needle must be noted, then divided by two to obtain the actual clearance value. If it exceeds the stem-to-guide clearance limit found in this Chapter’s Specifications, the valve guides should be renewed. After this is done, if there’s still some doubt regarding the condition of the valve guides they should be checked by an automotive machine workshop (the cost should be minimal).

Valves

16 Carefully inspect each valve face for

uneven wear, deformation, cracks, pits and burned areas. Check the valve stem for scuffing and galling and the neck for cracks. Rotate the valve and check for any obvious indication that it’s bent. Look for pits and excessive wear on the end of the stem. The presence of any of these conditions indicates the need for valve service by an automotive machine workshop.

17 Measure the margin width on each valve (see illustration). Any valve with a margin

narrower than 1/32-inch will have to be replaced with a new valve.

Valve components

18 Check each valve spring for wear (on the

ends) and pits. Measure the free length and compare it to this Chapter’s Specifications (see illustration). Any springs that are shorter than specified have sagged and should not be re-used. The tension of all springs should be pressure checked with a special fixture before deciding that they’re suitable for use in a rebuilt engine (take the springs to an automotive machine workshop for this check).

Note: If any valve springs are found broken on 1988 or 1989 engines, all springs should be replaced with the improved springs used in 1990 (after VIN 9EPCLA120245) and later engines. They are identified with a white stripe. If your engine has springs with whitestripes, they have already been replaced, and only broken ones need be replaced.

19 Stand each spring on a flat surface and check it for squareness (see illustration). If any of the springs are distorted or sagged, renew all of the springs. 20 Check the spring retainers and keepers for obvious wear and cracks. Any questionable parts should be renewed, as extensive damage will occur if they fail during engine operation. 21 If the inspection process indicates that the valve components are in generally poor condition and worn beyond the limits specified, which is usually the case in an engine that’s being overhauled, reassemble the valves in the cylinder head and refer to Section 11 for valve servicing recommendations.

11 Valves - servicing

1 Because of the complex nature of the job and the special tools and equipment needed, servicing of the valves, the valve seats and the valve guides, commonly known as a valve job, should be done by a professional. 2 The home mechanic can remove and dismantle the cylinder head(s), do the initial cleaning and inspection, then reassemble and deliver them to a dealer service department or an automotive machine workshop for the actual service work. Doing the inspection will enable you to see what condition the cylinder head(s) and valvetrain components are in and will ensure that you know what work and new parts are required when dealing with an automotive machine workshop. 3 The dealer service department, or automotive machine workshop, will remove the valves and springs, will recondition or renew the valves and valve seats, recondition the valve guides, check and renew the valve springs, spring retainers and keepers (as necessary), replace the valve seals with new ones, reassemble the valve components and make sure the installed spring height is correct. The cylinder head gasket surface will also be resurfaced if it’s warped. 4 After the valve job has been performed by a professional, the cylinder head(s) will be in like new condition. When the cylinder heads are returned, be sure to clean them again before refitting on the engine to remove any metal particles and abrasive grit that may still be present from the valve service or cylinder head resurfacing operations. Use compressed air, if available, to blow out all the oil holes and passages.

12 Cylinder head - reassembly

1 Regardless of whether or not the cylinder head was sent to an automotive machine workshop for valve servicing, make sure it’s clean before beginning reassembly. Renew the cylinder head rear plate gasket any time that the engine is overhauled or the cylinder head is reconditioned (see Part A of this Chapter for renewal procedure). 2 If the cylinder head was sent out for valve servicing, the valves and related components will already be in place. Begin the reassembly procedure with paragraph 8. 3 Refit new seals on each of the valve guides. Gently push each valve seal into place until it’s seated on the guide.

Caution: Don’t hammer on the valve seals once they’re seated or you may damage them. Don’t twist or cock the seals during refitting or they won’t seat properly on the valve stems.

2B•8 Engine removal and overhaul procedures

10.15 Use a small dial bore gauge to

determine the inside diameter of the valve

guides - subtract the valve stem diameter to determine the stem-to-guide clearance

10.17 The margin width on each valve

must be as specified (if no margin exists,

the valve cannot be re-used)

10.18 Measure the free length of each

valve spring with a dial or vernier caliper

10.19 Check each valve spring for squareness

3261 Jaguar XJ6

4 Beginning at one end of the cylinder head, lubricate and refit the first valve. Apply molybase grease or clean engine oil to the valve stem. 5 Place the spring seat or shim(s) over the valve guide and set the valve spring and retainer in place. 6 Compress the springs with a valve spring compressor and carefully refit the keepers in the upper groove, then slowly release the compressor and make sure the keepers seat properly. Apply a small dab of grease to each keeper to hold it in place if necessary (see

Haynes Hint). 7 Repeat the procedure for the remaining

valves. Be sure to return the components to their original locations - don’t mix them up!

13 Pistons/connecting rods -

removal

Note : Prior to removing the piston/connecting rod assemblies, remove the cylinder head(s), the sump and the oil pump transfer tubes by referring to Chapter 2A.

1 Use your fingernail to feel if a ridge has formed at the upper limit of ring travel (about 1/4-inch down from the top of each cylinder). If carbon deposits or cylinder wear have produced ridges, they must be completely removed with a special tool (see illustration). Follow the manufacturer’s instructions provided with the tool. Failure to remove the ridges before attempting to remove the piston/connecting rod assemblies may result in piston damage. 2 After the cylinder ridges have been removed, turn the engine upside-down so the crankshaft is facing up. Remove the screws and the front and rear baffle plates from the bottom of the engine block (see illustration). 3 Before the connecting rods are removed, check the endplay with a feeler gauge. Slide the blade between the first connecting rod and the crankshaft throw until the play is removed (see illustration). The endplay is equal to the thickness of the feeler gauge(s). If the endplay exceeds the specified service limit, new connecting rods will be required. If

new rods (or a new crankshaft) are installed, the endplay may fall under the service limit (if it does, the rods will have to be machined to restore it - consult an automotive machine workshop for advice if necessary). Repeat the procedure for the remaining connecting rods. 4 Check the connecting rods and caps for identification marks. If they aren’t plainly marked, use a small centre punch to make the appropriate number of indentations on each rod and cap (1, 2, 3, etc, depending on the cylinder they’re associated with) (see illustration). 5 Loosen each of the connecting rod cap nuts 1/2-turn at a time until they can be removed by hand. Remove the number one connecting rod cap and bearing insert. Don’t drop the bearing insert out of the cap. Note: These engines use

special connecting rod and main bearing cap bolts that are designed to be used one time only. They can be used during Plastigage checks, but must be replaced with new bolts when the engine is finally reassembled.

6 Slip a short length of plastic or rubber hose over each connecting rod cap bolt to protect the crankshaft journal and cylinder wall as the piston is removed (see illustration). 7 Remove the bearing insert and push the connecting rod/piston assembly out through the top of the engine. Use a wooden hammer handle to push on the upper bearing surface in the connecting rod. If resistance is felt, double-check to make sure that all of the ridge was removed from the cylinder.

Engine removal and overhaul procedures 2B•9

13.2 Remove the screws (arrowed) and remove the front and rear baffle plates

13.3 Check the connecting rod side

clearance with a feeler gauge as shown

13.4 The connecting rods and caps should be marked by cylinder number - if they

aren’t, mark them with a centre punch to

avoid confusion during reassembly

13.6 To prevent damage to the crankshaft

journals and cylinder walls, slip sections of

hose over the connecting rod bolts before

removing the pistons

3261 Jaguar XJ6

13.1 A ridge reamer is required to remove the ridge from the top of each cylinder -

do this before removing the pistons!

The keepers are easier to fit if a small amount of grease is applied to keep them in place

8 Repeat the procedure for the remaining cylinders. Note: Turn the crankshaft as

needed to position the piston/connecting rod assembly to be removed close to parallel with the cylinder bore - i.e. don’t try to drive it out while at a large angle to the bore.

9 After removal, reassemble the connecting rod caps and bearing inserts in their respective connecting rods and refit the cap nuts/bolts finger tight. Leaving the old bearing inserts in place until reassembly will help prevent the big-end bearing surfaces from being accidentally nicked or gouged. 10 Don’t separate the pistons from the connecting rods (see Section 18 for additional information).

14 Crankshaft - removal

Note: The rear main oil seal and retainer must be removed from the engine block before proceeding with crankshaft removal (see Part

A of this Chapter). 1 Before the crankshaft is removed, check the endplay. Mount a dial indicator to the front of the engine with the stem in line with, and just touching, the end of the crankshaft (see

illustration).

2 Push the crankshaft all the way to the rear

and zero the dial indicator. Next, pry the crankshaft to the front as far as possible and check the reading on the dial indicator. The distance that it moves is the endplay. If it’s greater than that specified in this Chapter’s Specifications, check the crankshaft thrust surfaces for wear. If no wear is evident, new thrust washers should correct the endplay. 3 If a dial indicator isn’t available, feeler gauges can be used. Gently pry or push the crankshaft all the way to the front of the engine. Slip feeler gauges between the crankshaft and the front face of the number 4 (thrust) main bearing to determine the clearance (see illustration). 4 Check the main bearing caps to see if they’re marked to indicate their locations. They should be numbered consecutively from the front of the engine to the rear. If they aren’t, mark them with number stamping dies or a centre punch. Main bearing caps generally have a cast-in arrow, which points to the front of the engine. Loosen the main bearing cap bolts 1/4-turn at a time each, stating at the ends and working toward the centre, until they can be removed by hand. 5 The main bearing caps are numbered on the right side with corresponding numbers stamped into the sump rail on the same side (see illustration). Gently tap the caps with a

soft-face hammer, then separate them from the engine block. If necessary, use the bolts as levers to remove the main bearing caps. Try not to drop the bearing inserts if they come out with the caps. Note: The number

four main bearing is the thrust bearing and is not numbered.

6 Carefully lift the crankshaft out of the engine. It may be a good idea to have an assistant available, since the crankshaft is quite heavy. With the bearing inserts in place in the engine block and main bearing caps, return the main bearing caps to their respective locations on the engine block and tighten the bolts finger tight.

15 Engine block - cleaning

Caution: The core plugs (also known as freeze or soft plugs) may be difficult or impossible to retrieve if they’re driven completely into the engine block coolant passages.

1 Using the blunt end of a punch, tap in on the outer edge of the core plug to turn the plug sideways in the bore. Then using pliers, pull the core plug from the engine block (see illustrations).

2B•10 Engine removal and overhaul procedures

14.5 The right side of each main bearing

cap is stamped with a number (left arrow)

that corresponds to the stamped number

on the pan rail (right arrow)

15.1a A hammer and a large punch can be used to knock the core plugs sideways in

their bores

15.1b Pull the core plugs from the engine block with pliers

3261 Jaguar XJ6

14.1 Checking crankshaft endplay with a dial indicator 14.3 Checking crankshaft endplay with a feeler gauge

2 Using a gasket scraper, remove all traces of

gasket material from the engine block. Be very careful not to nick or gouge the gasket sealing surfaces. 3 Remove the main bearing caps and separate the bearing inserts from the caps and the engine block. Tag the bearings, indicating which cylinder they were removed from and whether they were in the cap or the engine block, then set them aside. 4 Remove all of the threaded oil gallery plugs from the engine block. The plugs are usually very tight - they may have to be drilled out and the holes retapped. Use new plugs when the engine is reassembled. 5 If the engine is extremely dirty, it should be taken to an automotive machine workshop to be steam cleaned or hot tanked. 6 After the engine block is returned, clean all oil holes and oil galleries one more time. Brushes specifically designed for this purpose are available at most car accessory outlets. Flush the passages with warm water until the water runs clear, dry the engine block thoroughly and wipe all machined surfaces with a light, rust preventive oil. If you have access to compressed air, use it to speed the drying process and to blow out all the oil holes and galleries.

Warning: Wear eye protection when using compressed air!

7 If the engine block isn’t extremely dirty or sludged up, you can do an adequate cleaning job with hot soapy water and a stiff brush. Take plenty of time and do a thorough job. Regardless of the cleaning method used, be sure to clean all oil holes and galleries very thoroughly, dry the engine block completely and coat all machined surfaces with light oil. 8 The threaded holes in the engine block must be clean to ensure accurate torque readings during reassembly. Run the proper size tap into each of the holes to remove rust, corrosion, thread sealant or sludge and restore damaged threads (see illustration). If possible, use compressed air to clear the holes of debris produced by this operation. 9 Refit the main bearing caps and tighten the bolts finger tight. 10 After coating the sealing surfaces of the new core plugs with suitable sealant, refit them in the engine block (see illustration). Make sure they’re driven in straight and seated properly or leakage could result. Special tools are available for this purpose, but a large socket, with an outside diameter that will just slip into the core plug, a 1/2-inch

drive extension and a hammer will work just as well. 11 Apply non-hardening sealant (such as Permatex no. 2 or Teflon pipe sealant) to the new oil gallery plugs and thread them into the holes in the engine block. Make sure they’re tightened securely. 12 If the engine isn’t going to be reassembled right away, cover it with a large plastic trash bag to keep it clean.

16 Engine block - inspection

1 Before the engine block is inspected, it should be cleaned as described in Section 15. 2 Visually check the engine block for cracks, rust and corrosion (see illustration 10.12). Look for stripped threads in the threaded holes. It’s also a good idea to have the engine block checked for hidden cracks by an automotive machine workshop that has the special equipment to do this type of work, especially if the vehicle had a history of overheating or using coolant. If defects are found, have the engine block repaired, if possible, or renewed. If the top of the engine block has been eroded by coolant leakage and the erosion is near the cylinder bores, the engine block must be renewed. 3 Check the cylinder bores for scuffing and scoring. 4 Check the cylinders for taper and out-ofround conditions as follows (see illustrations): 5 Measure the diameter of each cylinder at the top (just under the ridge area), centre and bottom of the cylinder bore, parallel to the crankshaft axis. 6 Next, measure each cylinder’s diameter at the same three locations perpendicular to the crankshaft axis. 7 The taper of each cylinder is the difference between the bore diameter at the top of the cylinder and the diameter at the bottom. The out-of-round specification of the cylinder bore

Engine removal and overhaul procedures 2B•11

16.4a Measure the diameter of each

cylinder at 90° to engine centreline (A), and

parallel to engine centreline (B) - out-of-

round is the difference between A and B;

taper is the difference between A and B at

the top of the cylinder and A and B at the

bottom of the cylinder

16.4b The ability to “feel” when the

telescoping gauge is at the correct point

will be developed over time, so work

slowly and repeat the check until you’re

satisfied that the bore measurement is

accurate

3261 Jaguar XJ6

15.8 All bolt holes in the engine block particularly the main bearing cap and

cylinder head bolt holes - should be

cleaned and restored with a tap (remove

debris from holes after this is done)

15.10 A large socket on an extension can be used to drive the new core plugs into

the bores

16.4c The gauge is then measured with a micrometer to determine the bore size

is the difference between the parallel and perpendicular readings. Compare your results to this Chapter’s Specifications. 8 If the cylinder walls are badly scuffed or scored, or if they’re out-of-round or tapered beyond the limits given in this Chapter’s Specifications, have the engine block rebored and honed at an automotive machine workshop. If a rebore is done, oversize pistons and rings will be required. 9 Using a precision straightedge and feeler gauge, check the engine block deck (the surface that mates with the cylinder head) for distortion (see illustration 10.13). If it’s distorted beyond the specified limit, it can be resurfaced by an automotive machine workshop. 10 If the cylinders are in reasonably good condition and not worn to the outside of the limits, and if the piston-to-cylinder clearances can be maintained properly, then they don’t have to be rebored. Honing is all that’s necessary (refer to Section 17).

17 Cylinder honing

1 Prior to engine reassembly, the cylinder bores must be honed so the new piston rings will seat correctly and provide the best possible combustion chamber seal. Note: If

you don’t have the tools or don’t want to tackle the honing operation, most automotive machine shops will do it for a reasonable fee.

2 Before honing the cylinders, refit the main bearing caps (without bearing inserts) and tighten the bolts to the specified torque. 3 Two types of cylinder hones are commonly available - the flex hone or “bottle brush” type and the more traditional surfacing hone with spring-loaded stones. Both will do the job, but for the less-experienced mechanic the “bottle brush” hone will probably be easier to use. You’ll also need some paraffin or honing oil, rags and a variable-speed electric drill motor. The drill motor should be operated at a steady, slow speed. Proceed as follows:

a) Mount the hone in the drill motor,

compress the stones and slip it into the first cylinder (see illustration).

Warning: Be sure to wear safety goggles or a face shield!

b) Lubricate the cylinder with plenty of

honing oil, turn on the drill and move the hone up-and-down in the cylinder at a pace that will produce a fine crosshatch pattern on the cylinder walls. Ideally, the crosshatch lines should intersect at approximately a 60° angle (see illustration). Be sure to use plenty of lubricant and don’t take off any more material than is absolutely necessary to produce the desired finish. Note: Piston ring manufacturers may specify a smaller

crosshatch angle than the traditional 60° read and follow any instructions included with the new rings.

c) Don’t withdraw the hone from the cylinder

while it’s running. Instead, shut off the drill and continue moving the hone up-anddown in the cylinder until it comes to a complete stop, then compress the stones and withdraw the hone. If you’re using a “bottle brush” type hone, stop the drill motor, then turn the chuck in the normal direction of rotation while withdrawing the hone from the cylinder.

d) Wipe the oil out of the cylinder and repeat

the procedure for the remaining cylinders.

4 After the honing job is complete, chamfer the top edges of the cylinder bores with a small file so the rings won’t catch when the pistons are installed. Be very careful not to nick the cylinder walls with the end of the file. 5 The entire engine block must be washed again very thoroughly with warm, soapy water to remove all traces of the abrasive grit produced during the honing operation. Note:

The bores can be considered clean when a lint-free white cloth - dampened with clean engine oil - used to wipe them out doesn’t pick up any more honing residue, which will show up as grey areas on the cloth. Be sure to run a brush through all oil holes and galleries and flush them with running water.

6 After rinsing, dry the engine block and apply a coat of light rust preventive oil to all machined surfaces. Wrap the engine block in a plastic bag to keep it clean and set it aside until reassembly.

18 Pistons/connecting rods -

inspection

1 Before the inspection process can be carried out, the piston/connecting rod assemblies must be cleaned and the original piston rings removed from the pistons. Note:

Always use new piston rings when the engine is reassembled.

2 Using a piston ring refitting tool, carefully remove the rings from the pistons. Be careful not to nick or gouge the pistons in the process. 3 Scrape all traces of carbon from the top of the piston. A hand-held wire brush or a piece of fine emery cloth can be used once the majority of the deposits have been scraped away. Do not, under any circumstances, use a wire brush mounted in a drill motor to remove deposits from the pistons. The piston material is soft and may be eroded away by the wire brush. 4 Use a piston ring groove-cleaning tool to remove carbon deposits from the ring grooves. If a tool isn’t available, a piece broken off the old ring will do the job. Be very careful to remove only the carbon deposits don’t remove any metal and do not nick or scratch the sides of the ring grooves (see

illustrations). 5 Once the deposits have been removed,

clean the piston/connecting rod assemblies with solvent and dry them with compressed air (if available). Make sure the oil return holes

2B•12 Engine removal and overhaul procedures

17.3a A “bottle brush” hone will produce better results if you have never done

cylinder honing before

17.3b The cylinder hone should leave a

smooth, crosshatch pattern with the lines

intersecting at approximately a 60° angle

18.4a The piston ring grooves can be

cleaned with a special tool, as shown . . .

18.4b . . . or a section of a broken ring

3261 Jaguar XJ6

in the back sides of the ring grooves and the oil hole in the lower end of each rod are clear. 6 If the pistons and cylinder walls aren’t damaged or worn excessively, and if the engine block is not rebored, new pistons won’t be necessary. Normal piston wear appears as even vertical wear on the piston thrust surfaces and slight looseness of the top ring in its groove. New piston rings, however, should always be used when an engine is rebuilt. 7 Carefully inspect each piston for cracks around the skirt, at the pin bosses and at the ring lands.

Caution: Some early 1988 3.6 litre engines (before engine no. 9D 121113) have incorrectly-stamped pistons. On these, the word FRONT is actually stamped on the rear of the pistons. Correct pistons will have the cast arrows on the inside of the skirt to your left when facing the word FRONT.

8 Look for scoring and scuffing on the thrust faces of the skirt, holes in the piston crown and burned areas at the edge of the crown. If the skirt is scored or scuffed, the engine may have been suffering from overheating and/or abnormal combustion, which caused excessively high operating temperatures. The cooling and lubrication systems should be checked thoroughly. A hole in the piston crown is an indication that abnormal combustion (pre-ignition) was occurring. Burned areas at the edge of the piston crown are usually evidence of spark knock (detonation). If any of the above problems exist, the causes must be corrected or the damage will occur again. The causes may include intake air leaks, incorrect air/fuel mixture, incorrect ignition timing and EGR system malfunctions. 9 Corrosion of the piston, in the form of small pits, indicates that coolant is leaking into the combustion chamber and/or the crankcase. Again, the cause must be corrected or the problem may persist in the rebuilt engine. 10 Measure the piston ring groove clearance by laying a new piston ring in each ring groove and slipping a feeler gauge in beside it (see illustration). Check the clearance at three or four locations around each groove. Be sure to

use the correct ring for each groove - they are different. If the clearance is greater than that listed in this Chapter’s Specifications, new pistons will have to be used. 11 Check the piston-to-bore clearance by measuring the bore (see Section 16) and the piston diameter. Make sure the pistons and bores are correctly matched. Measure the piston across the skirt, at a 90° angle to the piston pin (see illustration). Subtract the piston diameter from the bore diameter to obtain the clearance. If it’s greater than specified, the engine block will have to be rebored and new pistons and rings installed. 12 Check the piston-to-rod clearance by twisting the piston and rod in opposite directions. Any noticeable play indicates excessive wear, which must be corrected. 13 If the pistons must be removed from the connecting rods for any reason, the rods should be taken to an automotive machine workshop, to be checked for bend and twist, since automotive machine shops have special equipment for this purpose. 14 Check the connecting rods for cracks and other damage. Temporarily remove the rod caps, lift out the old bearing inserts, wipe the connecting rod and cap bearing surfaces clean and inspect them for nicks, gouges and scratches. After checking the connecting rods, renew the old bearings, slip the caps into place and tighten the nuts finger tight.

Note: If the engine is being rebuilt because of a connecting rod knock, be sure to refit new rods.

19 Crankshaft - inspection

1 Clean the crankshaft with solvent and dry it with compressed air (if available). Be sure to clean the oil holes with a stiff brush and flush them with solvent. 2 Check the main and connecting rod bearing journals for uneven wear, scoring, pits and cracks. 3 Remove all burrs from the crankshaft oil holes with a stone, file or scraper.

4 Check the remainder of the crankshaft for cracks and other damage. It should be magnafluxed to reveal hidden cracks - an automotive machine workshop will handle the procedure. 5 Using a micrometer, measure the diameter of the main and connecting rod journals and compare the results to this Chapter’s Specifications (see illustration). By measuring the diameter at a number of points around each journal’s circumference, you’ll be able to determine whether or not the journal is out-of-round. Take the measurement at each end of the journal, near the crank throws, to determine if the journal is tapered. Crankshaft runout should be checked also, but large Vblocks and a dial indicator are needed to do it correctly. If you don’t have the equipment, have a machine workshop check the runout. 6 If the crankshaft journals are damaged, tapered, out-of-round or worn beyond the limits given in the Specifications, have the crankshaft reground by an automotive machine workshop. Be sure to use the correct size bearing inserts if the crankshaft is reconditioned. 7 Check the oil seal journals at each end of the crankshaft for wear and damage. If the seal has worn a groove in the journal, or if it’s nicked or scratched, the new seal may leak when the engine is reassembled. In some cases, an automotive machine workshop may be able to repair the journal by pressing on a thin sleeve. If repair isn’t feasible, a new or different crankshaft should be installed. 8 Refer to Section 20 and examine the main and big-end bearing inserts.

20 Main and big-end bearings -

inspection and selection

Inspection

1 Even though the main and big-end bearings should be replaced with new ones during the engine overhaul, the old bearings should be retained for close examination, as they may

Engine removal and overhaul procedures 2B•13

19.5 Measure the diameter of each

crankshaft journal at several points to

detect taper and out-of-round conditions

3261 Jaguar XJ6

18.10 Check the ring groove clearance with a feeler gauge at several points

around the groove

18.11 Measure the piston diameter at a

90° angle to the piston pin, at the bottom

of the piston pin area - a precision caliper

may be used if a micrometer isn’t available

reveal valuable information about the condition of the engine (see illustration). 2 Bearing failure occurs because of lack of lubrication, the presence of dirt or other foreign particles, overloading the engine and corrosion. Regardless of the cause of failure, it must be corrected before the engine is reassembled to prevent it from happening again. 3 When examining the bearings, remove them from the engine block, the main bearing caps, the connecting rods and the rod caps and lay them out on a clean surface in the same general position as their location in the engine. This will enable you to match any bearing problems with the corresponding crankshaft journal. 4 Dirt and other foreign particles get into the engine in a variety of ways. It may be left in the engine during assembly, or it may pass through filters or the PCV system. It may get into the oil, and from there into the bearings. Metal chips from machining operations and normal engine wear are often present. Abrasives are sometimes left in engine components after reconditioning, especially when parts are not thoroughly cleaned using the proper cleaning methods. Whatever the source, these foreign objects often end up embedded in the soft bearing material and are easily recognised. Large particles will not embed in the bearing and will score or gouge the bearing and journal. The best prevention for this cause of bearing failure is to clean all parts thoroughly and keep everything spotlessly clean during engine assembly. Frequent and regular engine oil and filter changes are also recommended.

5 Lack of lubrication (or lubrication breakdown) has a number of interrelated causes. Excessive heat (which thins the oil), overloading (which squeezes the oil from the bearing face) and oil leakage or throw off (from excessive bearing clearances, worn oil pump or high engine speeds) all contribute to lubrication breakdown. Blocked oil passages, which usually are the result of misaligned oil holes in a bearing shell, will also oil starve a bearing and destroy it. When lack of lubrication is the cause of bearing failure, the bearing material is wiped or extruded from the steel backing of the bearing. Temperatures may increase to the point where the steel backing turns blue from overheating. 6 Driving habits can have a definite effect on bearing life. Low speed operation in too high a gear (labouring the engine) puts extremely high loads on bearings, which tends to squeeze out the oil film. These loads cause the bearings to flex, which produces fine cracks in the bearing face (fatigue failure). Eventually the bearing material will loosen in pieces and tear away from the steel backing. Short trip driving leads to corrosion of bearings because insufficient engine heat is produced to drive off the condensed water and corrosive gases. These products collect in the engine oil, forming acid and sludge. As the oil is carried to the engine bearings, the acid attacks and corrodes the bearing material. 7 Incorrect bearing refitting during engine assembly will lead to bearing failure as well. Tight-fitting bearings leave insufficient bearing oil clearance, and this will lead to oil

starvation. Dirt or foreign particles trapped behind a bearing insert result in high spots on the bearing which lead to failure.

Selection

8 If the original bearings are worn or damaged, or if the oil clearances are incorrect (see Sections 23 or 25), the following procedures should be used to select the correct new bearings for engine reassembly. However, if the crankshaft has been reground, new undersize bearings must be installed the following procedure should not be used if undersize bearings are required! The automotive machine workshop that reconditions the crankshaft will provide or help you select the correct-size bearings. Regardless of how the bearing sizes are determined, use the oil clearance, measured with Plastigage, as a guide to ensure the bearings are the right size. 9 If you need to use a STANDARD size main or big-end bearing, refit one that has the same number as the original bearing. Note: 4.0 litre

engines after #164637 have sized crankshafts and bearings in three grades, indicated by colour and letter. The codes are stamped into the front throw of the crankshaft (see illustration). Match replacement bearings by the colour codes: pink (P), white (W) or green (G) for main bearings; red (R), yellow (Y) or blue (B) for the three grades of big-end bearings.

10 Remember, the oil clearance is the final judge when selecting new bearing sizes. If you have any questions or are unsure which bearings to use, get help from a dealer parts or service department.

2B•14 Engine removal and overhaul procedures

3261 Jaguar XJ6

20.1 When inspecting the main and big-end bearings, look for these problems

20.9 Later model 4.0 litre engines have graded journals and bearings, with the markings indicated on the front throw of the crankshaft - “A” indicates the front of the engine, “B” indicates

the codes for the main journals/bearings, and “C” indicates the

connecting rod journal grades

21 Engine overhaul -

reassembly sequence

1 Before beginning engine reassembly, make sure you have all the necessary new parts, gaskets and seals as well as the following items on hand:

Common hand tools A 1/2-inch drive torque wrench Piston ring refitting tool Piston ring compressor Short lengths of rubber or plastic hose to fit over connecting rod bolts Plastigauge Feeler gauges A fine-tooth file New engine oil Engine assembly lube or moly-base grease Gasket sealer Thread locking compound

Special Jaguar tools:

Engine lifting brackets (18G 1465) Timing damper simulator (18E 1436) Camshaft TDC tool (18G 1433)

2 In order to save time and avoid problems, engine reassembly must be done in the following general order:

Piston rings (Part B) Crankshaft and main bearings (Part B) Piston/connecting rod assemblies (Part B) Rear main (crankshaft) oil seal (Part B) Auxiliary shaft (Part A) Timing chains and sprockets (Part A) Oil pump (Part A) Timing chain cover (Part A) Cylinder head and lifters (Part A) Camshafts (Part A) Oil pick-up (Part A) Sump (Part A) Intake and exhaust manifolds (Part A) Valve cover (Part A) Flywheel/driveplate (Part A)

22 Piston rings - refitting

1 Before refitting the new piston rings, the ring end gaps must be checked. It’s assumed that the piston ring groove clearance has been checked and verified correct (see Section 18). 2 Lay out the piston/connecting rod assemblies and the new ring sets so the ring sets will be matched with the same piston and cylinder during the end gap measurement and engine assembly. 3 Insert the top (number one) ring into the first cylinder and square it up with the cylinder walls by pushing it in with the top of the piston (see illustration). The ring should be near the bottom of the cylinder, at the lower limit of ring travel. 4 To measure the end gap, slip feeler gauges between the ends of the ring until a gauge equal to the gap width is found (see illustration). The feeler gauge should slide between the ring ends with a slight amount of drag. Compare the measurement to that found in this Chapter’s Specifications. If the gap is larger or smaller than specified, double-check to make sure you have the correct rings before proceeding. 5 If the gap is too small, it must be enlarged or the ring ends may come in contact with each other during engine operation, which can cause serious damage to the engine. The end gap can be increased by filing the ring ends very carefully with a fine file. Mount the

file in a vice equipped with soft jaws, slip the ring over the file with the ends contacting the file face and slowly move the ring to remove material from the ends (see illustration).

Caution: When performing this operation, file only from the outside in, and after the correct gap is achieved, deburr the filed ends of the rings with a fine whetstone.

6 Excess end gap isn’t critical unless it’s greater than Specifications. Again, doublecheck to make sure you have the correct rings for your engine. 7 Repeat the procedure for each ring that will be installed in the first cylinder and for each ring in the remaining cylinders. Remember to keep rings, pistons and cylinders matched. 8 Once the ring end gaps have been checked/corrected, the rings can be installed on the pistons. 9 The oil control ring (lowest one on the piston) is usually installed first. It’s composed of three separate components. Slip the spacer/expander into the groove (see illustration). If an anti-rotation tang is used, make sure it’s inserted into the drilled hole in the ring groove. Next, refit the lower side rail. Don’t use a piston ring refitting tool on the oil ring side rails, as they may be damaged. Instead, place one end of the side rail into the groove between the spacer/expander and the ring land, hold it firmly in place and slide a finger around the piston while pushing the rail into the groove (see illustrations). Next, refit the upper side rail in the same manner. 10 After the three oil ring components have been installed, check to make sure that both

Engine removal and overhaul procedures 2B•15

22.3 When checking piston ring end gap, the ring must be square in the cylinder

bore (this is done by pushing the ring down

with the top of a piston as shown)

22.4 With the ring square in the cylinder, measure the end gap with a feeler gauge

22.5 If the end gap is too small, clamp a

file in a vice and file the ring ends (from the

outside in only) to enlarge the gap slightly

22.9a Refit the spacer/expander in the oil control ring groove

22.9b DO NOT use a piston ring refitting tool when refitting the oil ring side rails

3261 Jaguar XJ6

the upper and lower side rails can be turned smoothly in the ring groove. 11 The number two (middle) ring is installed next. It’s usually stamped with a mark which must face up, toward the top of the piston.

Note: Always follow the instructions on the ring package or box - different manufacturers may require different approaches. Do not mix up the top and middle rings, as they have different cross sections.

12 Use a piston ring refitting tool and make sure the ring’s identification mark is facing the top of the piston, then slip the ring into the middle groove on the piston (see illustration). Don’t expand the ring any more than necessary to slide it over the piston. 13 Refit the number one (top) ring in the same manner. Make sure the mark is facing up. Be careful not to confuse the number one and number two rings. 14 Repeat the procedure for the remaining pistons and rings.

23 Crankshaft - refitting and

main bearing oil clearance check

1 Crankshaft refitting is the first major step in engine reassembly. It’s assumed at this point that the engine block and crankshaft have been cleaned, inspected and repaired or reconditioned. 2 Position the engine with the bottom facing up. 3 Remove the main bearing cap bolts and lift out the caps. Lay the caps out in the proper order. 4 If they’re still in place, remove the old bearing inserts from the engine block and the main bearing caps. Wipe the main bearing surfaces of the engine block and caps with a clean, lint free cloth. They must be kept spotlessly clean!

Main bearing oil clearance check

5 Clean the back sides of the new main bearing inserts and lay the bearing half with the oil groove in each main bearing saddle in

the engine block. Lay the other bearing half from each bearing set in the corresponding main bearing cap. Make sure the tab on each bearing insert fits into the recess in the engine block or cap. Also, the oil holes in the block must line up with the oil holes in the bearing insert.

Caution: Do not hammer the bearings into place and don’t nick or gouge the bearing faces. No lubrication should be used at this time.

6 The thrust bearings (washers) must be installed in the number four main bearing cap and saddle. 7 Clean the faces of the bearings in the engine block and the crankshaft main bearing journals with a clean, lint free cloth. Check or clean the oil holes in the crankshaft, as any dirt here can go only one way - straight through the new bearings. 8 Once you’re certain the crankshaft is clean, carefully lay it in position in the main bearings. 9 Before the crankshaft can be permanently installed, the main bearing oil clearance must be checked. 10 Trim several pieces of the appropriate size Plastigauge (they must be slightly shorter than the width of the main bearings) and place one piece on each crankshaft main bearing journal, parallel with the journal axis (see

illustration). 11 Clean the faces of the bearings in the

caps and refit the caps in their respective positions (don’t mix them up) with the arrows pointing toward the front of the engine. Don’t disturb the Plastigauge. Apply a light coat of oil to the bolt threads and the undersides of the bolt heads, then refit them. Note: Use the

old bolts for this step (save the new bolts for final refitting).

12 Tighten the main bearing cap bolts, in three steps, to the torque listed in this Chapter’s Specifications. Don’t rotate the crankshaft at any time during this operation! 13 Remove the bolts and carefully lift off the main bearing caps or cap assembly. Keep them in order. Don’t disturb the Plastigauge or rotate the crankshaft. If any of the main bearing caps are difficult to remove, tap them gently from side-to-side with a soft-face hammer to loosen them.

14 Compare the width of the crushed Plastigauge on each journal to the scale printed on the Plastigauge envelope to obtain the main bearing oil clearance (see illustration). Check the Specifications to make sure it’s correct. 15 If the clearance is not as specified, the bearing inserts may be the wrong size (which means different ones will be required - see Section 20). Before deciding that different inserts are needed, make sure that no dirt or oil was between the bearing inserts and the caps or engine block when the clearance was measured. If the Plastigauge is noticeably wider at one end than the other, the journal may be tapered (see Section 19). 16 Carefully scrape all traces of the Plastigauge material off the main bearing journals and/or the bearing faces. Don’t nick or scratch the bearing faces.

Final crankshaft refitting

17 Carefully lift the crankshaft out of the engine. Clean the bearing faces in the engine block, then apply a thin, uniform layer of clean moly-base grease or engine assembly lube to each of the bearing surfaces. Coat the thrust washers as well. 18 Lubricate the crankshaft surfaces that contact the oil seals with moly-base grease, engine assembly lube or clean engine oil. 19 Make sure the crankshaft journals are clean, then lay the crankshaft back in place in the engine block. Clean the faces of the bearings in the main bearing caps, then apply lubricant to them. Refit the main bearing caps in their respective positions with the arrows pointing toward the front of the engine. Note:

Be sure to refit the thrust washers (lubricated) with the number 4 main journal. The upper

(block side) thrust washers can be rotated into position around the crankshaft with the crankshaft installed in the engine block, with the thrust washer grooves facing OUT. The lower thrust washers should be placed on the main bearing caps with their grooves OUT. 20 For the final assembly, use only new bolts, for both the main bearings and the

2B•16 Engine removal and overhaul procedures

23.10 Lay the Plastigauge strips on the main bearing journals, parallel to the

crankshaft centreline

23.14 Compare the width of the crushed

Plastigauge to the scale on the envelope to

determine the main bearing oil clearance

(always take the measurement at the

widest point of the Plastigauge). Be sure to

use the correct scale - imperial and metric

scales are included

3261 Jaguar XJ6

22.12 Refit the compression rings with a ring expander - the mark must face up

connecting rods. Apply a light coat of oil to the bolt threads and the under sides of the bolt heads, then refit them. Tighten all main bearing cap bolts to the torque listed in this Chapter’s Specifications, starting in the centre and working out to the ends. 21 Rotate the crankshaft a number of times by hand to check for any obvious binding. 22 Check the crankshaft endplay with a feeler gauge or a dial indicator as described in Section 14. The endplay should be correct if the crankshaft thrust faces aren’t worn or damaged and new thrust washers have been installed. Note: If the end-play is too great,

even with the new thrust bearings, oversized thrust bearings are available. There are two sizes, 0.005-inch and 0.010-inch oversize.

23 Refit a new rear main oil seal, then bolt the retainer to the engine block (see Section 24).

24 Rear main oil seal refitting

1 The crankshaft must be installed first and the main bearing caps bolted in place, then the new seal should be installed in the retainer and the retainer bolted to the engine block. 2 Check the seal contact surface on the crankshaft very carefully for scratches and nicks that could damage the new seal lip and cause oil leaks. If the crankshaft is damaged, the only alternative is a new or different crankshaft. 3 Refer to Part A of this Chapter for refitting of the new rear seal, using the plastic alignment tool supplied with the engine overhaul gasket set.

25 Pistons/connecting rods -

refitting and big-end bearing oil clearance check

1 Before refitting the piston/connecting rod assemblies, the cylinder walls must be perfectly clean, the top edge of each cylinder must be chamfered, and the crankshaft must be in place. 2 Remove the cap from the end of the number one connecting rod (refer to the marks made during removal). Remove the original bearing inserts and wipe the bearing surfaces of the connecting rod and cap with a clean, lint-free cloth. They must be kept spotlessly clean.

Big-end bearing oil clearance check

3 Clean the back side of the new upper bearing insert, then lay it in place in the connecting rod. Make sure the tab on the bearing fits into the recess in the rod so the oil holes line up. Don’t hammer the bearing insert into place and be very careful not to nick or gouge the bearing face. Don’t lubricate the bearing at this time.

4 Clean the back side of the other bearing insert and refit it in the rod cap. Again, make sure the tab on the bearing fits into the recess in the cap, and don’t apply any lubricant. It’s critically important that the mating surfaces of the bearing and connecting rod are perfectly clean and oil free when they’re assembled. 5 Position the piston ring gaps at staggered intervals around the piston (see illustration). 6 Slip a section of plastic or rubber hose over each connecting rod cap bolt. 7 Lubricate the piston and rings with clean engine oil and attach a piston ring compressor to the piston. Leave the skirt protruding about 1/4-inch to guide the piston into the cylinder. The rings must be compressed until they’re flush with the piston. 8 Rotate the crankshaft until the number one connecting rod journal is at BDC (bottom dead centre) and apply a coat of engine oil to the cylinder wall. 9 With the word FRONT (or the arrow) on top of the piston facing the front of the engine (see illustration), gently insert the piston/ connecting rod assembly into the number one cylinder bore and rest the bottom edge of the ring compressor on the engine block. 10 Tap the top edge of the ring compressor to make sure it’s contacting the engine block around its entire circumference.

11 Gently tap on the top of the piston with the end of a wooden hammer handle (see illustration) while guiding the end of the connecting rod into place on the crankshaft journal. The piston rings may try to pop out of the ring compressor just before entering the cylinder bore, so keep some downward pressure on the ring compressor. Work slowly, and if any resistance is felt as the piston enters the cylinder, stop immediately. Find out what’s hanging up and fix it before proceeding.

Caution: Do not, for any reason, force the piston into the cylinder - you might break a ring and/or the piston.

12 Once the piston/connecting rod assembly is installed, the big-end bearing oil clearance must be checked before the rod cap is permanently bolted in place. 13 Cut a piece of the appropriate size Plastigauge slightly shorter than the width of the big-end bearing and lay it in place on the number one connecting rod journal, parallel with the journal axis (see illustration). 14 Clean the connecting rod cap bearing face, remove the protective hoses from the connecting rod bolts and refit the rod cap. Make sure the mating mark on the cap is on the same side as the mark on the connecting rod. Check the cap to make sure the front mark is facing the timing chain of the engine. 15 Apply a light coat of oil to the under sides of the nuts, then refit and tighten them to the torque listed in this Chapter’s Specifications,

Engine removal and overhaul procedures 2B•17

25.13 Lay the Plastigauge strips on each big-end bearing journal, parallel to the

crankshaft centreline

3261 Jaguar XJ6

25.5 Stagger the ring end gaps around the piston as shown

25.9 Pistons must be installed with the arrow (right arrow) or FRONT facing the front of the engine - left arrow indicates

piston size letter

25.11 The piston can be driven (gently) into the cylinder bore with the end of a

wooden or plastic hammer handle

A Oil ring rail gaps B Second compression ring gap C Oil ring spacer gap D Top compression ring gap

working up to it in three steps. Note: Use the old bolts for this step (save the new bolts for final refitting). Use a thin-wall socket to avoid

erroneous torque readings that can result if the socket is wedged between the rod cap and nut. If the socket tends to wedge itself between the nut and the cap, lift up on it slightly until it no longer contacts the cap. Do not rotate the crankshaft at any time during this operation. 16 Remove the nuts and detach the rod cap, being careful not to disturb the Plastigauge. 17 Compare the width of the crushed Plastigauge to the scale printed on the envelope to obtain the oil clearance (see illustration). Compare it to this Chapter’s Specifications to make sure the clearance is correct. 18 If the clearance is not as specified, the bearing inserts may be the wrong size (which means different ones will be required). Before deciding that different inserts are needed, make sure that no dirt or oil was between the bearing inserts and the connecting rod or cap when the clearance was measured. Also, recheck the journal diameter. If the Plastigauge was wider at one end than the other, the journal may be tapered (refer to Section 19).

Final connecting rod refitting

19 Carefully scrape all traces of the Plastigauge material off the rod journal and/or bearing face. Be very careful not to scratch

the bearing, use your fingernail or the edge of a credit card to remove the Plastigauge. 20 Make sure the bearing faces are perfectly clean, then apply a uniform layer of clean moly-base grease or engine assembly lube to both of them. You’ll have to push the piston higher into the cylinder to expose the face of the bearing insert in the connecting rod, be sure to slip the protective hoses over the connecting rod bolts first. 21 At this time, remove the original connecting rod bolts/nuts and replace them with new bolts/nuts. They are of a design which requires they be used only once. The old ones are OK for Plastigauge checking, but for final assembly use only new connecting rod bolts/nuts. Refit the rod cap and tighten the nuts to the torque listed in this Chapter’s Specifications. Again, work up to the torque in three steps. 22 Repeat the entire procedure for the remaining pistons/connecting rod assemblies. 23 The important points to remember are:

a) Keep the back sides of the bearing inserts

and the insides of the connecting rods and caps perfectly clean during assembly..

b) Make sure you have the correct piston/

connecting rod assembly for each cylinder.

c) The dimple on the piston must face the

front of the engine. d) Lubricate the cylinder walls with clean oil. e) Lubricate the bearing faces when refitting

the rod caps after the oil clearance has

been checked.

24 After all the piston/connecting rod assemblies have been properly installed, rotate the crankshaft a number of times by hand to check for any obvious binding. 25 As a final step, the connecting rod endplay must be checked. Refer to Section 13 for this procedure. 26 Compare the measured endplay to this Chapter’s Specifications to make sure it’s correct. If it was correct before dismantling and the original crankshaft and connecting rods were reinstalled, it should still be right. However, if new connecting rods or a new crankshaft were installed, the endplay may be

inadequate. If so, the connecting rods will have to be removed and taken to an automotive machine workshop for resizing.

26 Initial start-up

and running-in after overhaul

Warning: Have a suitable fire extinguisher handy when starting the engine for the first time.

1 Once the engine has been installed in the vehicle, double-check the engine oil and coolant levels. 2 With the spark plugs out of the engine and the ignition system and fuel pump disabled, crank the engine until oil pressure registers on the gauge or the light goes out. 3 Refit the spark plugs, hook up the plug leads and restore the ignition system and fuel pump functions. 4 Start the engine. It may take a few moments for the fuel system to build up pressure, but the engine should start without a great deal of effort. 5 After the engine starts, it should be allowed to warm up to normal operating temperature. While the engine is warming up, make a thorough check for fuel, oil and coolant leaks. 6 Shut the engine off and recheck the engine oil and coolant levels. 7 Drive the vehicle to an area with no traffic, accelerate from 30 to 50 mph, then allow the vehicle to slow to 30 mph with the throttle closed. Repeat the procedure 10 or 12 times. This will load the piston rings and cause them to seat properly against the cylinder walls. Check again for oil and coolant leaks. 8 Drive the vehicle gently for the first 500 miles (no sustained high speeds) and keep a constant check on the oil level. It is not unusual for an engine to use oil during the running-in period. 9 At approximately 500 to 600 miles, change the oil and filter. 10 For the next few hundred miles, drive the vehicle normally. Do not pamper it or abuse it. 11 After 2000 miles, change the oil and filter again and consider the engine run-in.

2B•18 Engine removal and overhaul procedures

25.17 Measure the width of the crushed Plastigauge to determine the big-end

bearing oil clearance

3261 Jaguar XJ6

Chapter 3

Cooling, heating and air conditioning systems

General

Radiator cap pressure rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.5 to 117.5 psi

Thermostat rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 to 207° F

Torque wrench settings Nm lbf ft

Coolant pipe to block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21

Fan assembly-to-drive hub nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21

Fan clutch-to-fan blade bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21

Thermostat cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21

Thermostat housing-to-block bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21

Water pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21

Air conditioning and heating system - check and maintenance . . . . 13

Air conditioning compressor - removal and refitting . . . . . . . . . . . . . 15

Air conditioning condenser - removal and refitting . . . . . . . . . . . . . . 16

Air conditioning evaporator and expansion valve - removal

and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Air conditioning receiver/drier - removal and refitting . . . . . . . . . . . . 14

Antifreeze/coolant - general information . . . . . . . . . . . . . . . . . . . . . . 2

Coolant level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Coolant temperature sender unit - check and renewal . . . . . . . . . . . .9

Cooling system check . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Cooling system draining, flushing and refilling . . . . . . . . See Chapter 1

Drivebelt check, adjustment and renewal . . . . . . . . . . . See Chapter 1

Engine cooling fans - check and renewal . . . . . . . . . . . . . . . . . . . . . 4

Engine oil cooler - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Heater and air conditioning blower motors -circuit check

and component renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Heater and air conditioning control assembly -

check, removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Heater core - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Radiator, expansion tank and coolant reservoir -

removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Thermostat - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Underbonnet hose check and renewal . . . . . . . . . . . . . . See Chapter 1

Water pump - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Water pump and pipes - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3•1

Specifications

Contents

Easy, suitable for

novice with little experience

Fairly easy, suitable for beginner with some experience

Fairly difficult,

suitable for competent DIY mechanic

Difficult, suitable for experienced DIY mechanic

Very difficult,

suitable for expert DIY or professional

Degrees of difficulty

1 General information

Engine cooling system

All vehicles covered by this manual employ a pressurised engine cooling system with thermostatically-controlled coolant circulation. An impeller type water pump mounted on the front of the block pumps coolant through the engine. The coolant flows around each cylinder and toward the rear of the engine. Cast-in coolant passages direct coolant around the intake and exhaust ports, near the spark plug areas and in proximity to the exhaust valve guides.

A wax-pellet type thermostat is located in the thermostat housing at the front of the engine. During warm up, the closed thermostat prevents coolant from circulating through the radiator. When the engine reaches normal operating temperature, the thermostat opens and allows hot coolant to travel through the radiator, where it is cooled before returning to the engine.

The cooling system is sealed by a pressuretype radiator cap. This raises the boiling point of the coolant, and the higher boiling point of the coolant increases the cooling efficiency of the radiator. If the system pressure exceeds the cap pressure-relief value, the excess pressure in the system forces the springloaded valve inside the cap off its seat and allows the coolant to escape through the overflow tube into a coolant reservoir. When

the system cools, the excess coolant is automatically drawn from the reservoir back into the radiator. This type of cooling system is known as a closed design because coolant that escapes past the pressure cap is saved and reused.

The Jaguar cooling system on 1988 and 1989 models has both a manifold tank and a coolant recovery tank. The manifold tank is the highest point in the cooling system and is the location of the “radiator” cap (the cap is not on the radiator). The recovery tank down in the passenger’s footwell collects heated coolant as described above. Models from 1990 to 1994 do not have a coolant recovery tank, but have an enlarged manifold tank. In all models, the recovery tank has a sensor in it to detect a low coolant level, and the instrument panel has a warning light to that effect.

Heating system

The heating system consists of two blower fans, one under the dash on the right and one on the left, and a heater core located within the heater/air conditioning assembly which is under the dash and behind the console. Hoses connect the heater core to the engine cooling system. Heater function is controlled by the heater/air conditioning control head on the dashboard. Hot engine coolant is circulated through the heater core. When the heater mode is activated, a flap door opens to expose the heater box to the passenger compartment. A fan switch on the control head activates the blower motor, which forces air through the core, heating the air.

Air conditioning system

The air conditioning system consists of a condenser mounted in front of the radiator, an evaporator mounted in the heat/air conditioning assembly behind the console and under the centre of the dash, a compressor mounted on the engine, a filter-drier which contains a high pressure relief valve and the plumbing connecting all of the above.

A blower fan forces the warmer air of the passenger compartment through the evaporator core (sort of a radiator-in-reverse), transferring the heat from the air to the refrigerant. The liquid refrigerant boils off into low pressure vapour, taking the heat with it when it leaves the evaporator. The compressor keeps refrigerant circulating through the system, pumping the warmed coolant through the condenser where it is cooled and then circulated back to the evaporator.

2 Antifreeze/coolant -

general information

Warning: Do not allow antifreeze to come in contact with your skin or painted surfaces of the

vehicle. Rinse off spills immediately with

plenty of water. Antifreeze is highly toxic if ingested. Never leave antifreeze lying around in an open container or in puddles on the floor; children and pets are attracted by it’s sweet smell and may drink it. Check with local authorities about disposing of used antifreeze. Many communities have collection centres which will see that antifreeze is disposed of safely. Never dump used antifreeze on the ground or into drains.

Note: Non-toxic antifreeze is now manufactured and available at local car accessory outlets, but even these types should be disposed of properly.

The cooling system should be filled with a water/ethylene-glycol based antifreeze solution, which will prevent freezing down to at least -20° F, or lower if local climate requires it. It also provides protection against corrosion and increases the coolant boiling point.

The cooling system should be drained, flushed and refilled every 24,000 miles or every two years (see Chapter 1). The use of antifreeze solutions for periods of longer than two years is likely to cause damage and encourage the formation of rust and scale in the system. If your tap water is “hard”, i.e. contains a lot of dissolved minerals, use distilled water with the antifreeze.

Before adding antifreeze to the system, check all hose connections, because antifreeze tends to leak through very minute openings. Engines do not normally consume coolant. Therefore, if the level goes down, find the cause and correct it.

The exact mixture of antifreeze-to-water you should use depends on the relative weather conditions. The mixture should contain at least 50-percent antifreeze, but should never contain more than 70-percent antifreeze. Consult the mixture ratio chart on the antifreeze container before adding coolant. Hydrometers are available at most car accessory outlets to test the ratio of antifreeze to water (see illustration). Use antifreeze which meets the vehicle manufacturer’s specifications.

3 Thermostat -

check and renewal

Warning: Do not attempt to remove the radiator cap, coolant or thermostat until the engine has cooled completely.

Check

1 Before assuming the thermostat is responsible for a cooling system problem, check the coolant level (Chapter 1), drivebelt tension (Chapter 1) and temperature gauge (or light) operation. 2 If the engine takes a long time to warm up (as indicated by the temperature gauge or heater operation), the thermostat is probably stuck open. Renew the thermostat. 3 If the engine runs hot, use your hand to check the temperature of the lower radiator hose.

Warning: Do this check with the engine off. Do not get your hands near the fan blades. If the

hose is not hot, but the engine is, the thermostat is probably stuck in the closed position, preventing the coolant inside the engine from travelling through the radiator. Renew the thermostat. Do not drive the vehicle without a thermostat. The computer may stay in open loop and emissions and fuel economy will suffer.

4 If the lower radiator hose is hot, it means that the coolant is flowing and the thermostat is open. Consult the Troubleshooting section at the front of this manual for further diagnosis.

Renewal

5 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

6 Drain the coolant from the radiator (see Chapter 1). 7 Remove the bolts from the thermostat cover (see illustration). If the cover doesn’t

3•2 Cooling, heating and air conditioning systems

3261 Jaguar XJ6

2.4 An inexpensive hydrometer can be

used to test the condition of your coolant

3.7 Remove the two bolts (small arrows) holding the thermostat cover to the

housing (large arrow)

pull loose, tap it with a soft-faced hammer. Do not use a screwdriver between the cover and the thermostat housing. 8 Remove the thermostat, noting the direction in which it was installed in the housing, and thoroughly clean the sealing surfaces.

9 Refit a new O-ring onto the thermostat (see illustration). Make sure it is evenly fitted all

the way around. 10 Apply a bead of RTV sealant to the thermostat housing. Refit the thermostat and housing, positioning the jiggle pin at the highest point. Note: The thermostat is usually

marked TOP on the radiator side for proper orientation.

11 Tighten the cover fasteners to the torque listed in this Chapter’s Specifications. 12 Refill the cooling system, run the engine and check for leaks and proper operation.

4 Engine cooling fans -

check and renewal

Mechanical fan (1988 to 1992 models)

Warning: Keep hands, hair, tools and clothing away from the fan when the engine is running. To

avoid injury or damage DO NOT operate the engine with a damaged fan. Do not attempt to repair fan blades - renew a damaged fan .

Check

Warning: In order to check the fan clutch, the engine will need to be at operating temperature,

so while going through checks prior to Step 6 be careful that the ignition is NOT switched on. Severe personal injury can result!

1 Symptoms of failure of the fan clutch are continuous noisy operation, looseness, vibration and evidence of silicone fluid leaks. 2 Rock the fan back and forth by hand to check for excessive bearing play. 3 With the engine cold, turn the blades by hand. The fan should turn freely. 4 Visually inspect for substantial fluid leakage from the fan clutch assembly, a deformed bimetal spring or grease leakage from the cooling fan bearing. If any of these conditions exist, renew the fan clutch. 5 When the engine is fully warmed up, turn off the ignition switch and disconnect the cable from the negative battery terminal. Turn the fan by hand. Some resistance should be felt. If the fan turns easily, renew the fan clutch.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make

sure you have the correct activation code before disconnecting the battery.

Removal and refitting

6 Leave the battery cable disconnected (see

the Caution in Step 5).

7 Remove the fan’s drivebelt (see Chapter 1). 8 Remove the nuts holding the fan assembly to the water pump (see illustration). Note:

You’ll have to “walk” the fan assembly forward as you loosen the nuts. There is not enough room to remove them all the way at one time.

9 The fan can be removed without removing the shroud, if you are only renewing the fan or clutch (see illustration). Be careful not to allow the blades contact the radiator fins. 10 Remove the two fan shroud mounting clips at the top of the shroud (see illustration). 11 Lift the shroud up and out of the engine compartment. The bottom of the fan shroud does not have any fasteners. It has two tangs on the bottom that slip out of slots in the body when pulled up. 12 The fan clutch can be unbolted from the fan blade assembly for renewal (see illustration).

Caution: To prevent silicone fluid from draining from the clutch assembly into the fan drive bearing and ruining the lubricant, DON’T place the clutch in a position with the rear pointing down. Store the clutch in its upright position if possible.

Cooling, heating and air conditioning systems 3•3

4.9 The fan can be removed with the shroud in place by angling it out of

the shroud

4.10 Pry out the two clips (arrow indicates the left one) at the top of the fan shroud

and lift out the shroud

3261 Jaguar XJ6

3.9 The thermostat is fitted with the spring end towards the

cylinder head - use a new O-ring (A) and position jiggle pin (B) up

4.8 Remove the four nuts (arrows indicate three shown here)

holding the fan/clutch assembly to the front of the water pump

4.12 Separate the fan clutch from the fan by removing the four bolts (arrowed)

13 Refitting is the reverse of removal. Tighten

the fan clutch-to-fan blade bolts and the fan assembly-to-drive hub nut to the torque listed in this Chapter’s Specifications.

Electric fans

Check

Warning: Keep your hands or clothing away from the fan blades at all times.

14 On 1988 through 1992 models, a single electric fan is mounted in front of the radiator, controlled by a thermostatic switch. Access to the fan is with the grille removed. The 1993 and 1994 models have a fan shroud assembly that includes two electric fans, and a “twin” thermostatic switch, with the assembly mounted on the engine side of the radiator. 15 If the electric fan does not come on at any time, bypass the thermostatic switch by disconnecting the electrical connector at the switch and connecting the two pins with a jumper wire (see illustration). If the fan now operates, renew the thermostatic switch. If the fan doesn’t operate, the problem is either the fan relay or the fan motor. On 1993 and 1994 models with twin electric fans, jumpering one set of connections in the plug from the switch should make both fans operate at slow speed (fans in series) and jumpering the other two should run both fans at higher speed (fans in parallel). In normal operation, the fans operate at the higher-speed only when the air conditioning is on, or when coolant temperature exceeds 212° F. When the coolant cools down to below 200° F, the fans revert to the normal speed. 16 To renew a defective thermostatic switch, allow the vehicle to cool off and drain the coolant (see Chapter 1). Remove the switch from the radiator and refit the new switch. Connect the electrical connector and test again for proper fan operation.

17 To test an inoperative fan motor (one that doesn’t come on when the engine gets hot or when the air conditioner is on), first check the fuses and/or fusible links (see Chapter 12). Then disconnect the electrical connector at the motor (refer to Chapter 11 for removal of the grille for access on front-mounted-fan models) and use fused jumper wires to connect the fan directly to the battery and to chassis ground (see illustration). If the fan still does not work, renew the fan motor.

Warning: Do not allow the test clips to contact each other or any metallic part of the vehicle.

18 If the motor tested OK in the previous test but is still inoperative, then the fault lies in the relay, fuse, or wiring. The fan relay can be tested for continuity (see Chapter 12).

Renewal

19 Disconnect the negative battery cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

20 Access the 1988 through 1992 single electric fan with the grille removed (see Chapter 11 for grille removal). Disconnect the electrical connector and remove the bolts holding the fan assembly to the body (see

illustration). 21 On 1993 and 1994 models, remove the

two bolts holding the fan shroud to the top of the radiator and lift the shroud/fans assembly from the vehicle. 22 If the fan on 1988 to 1992 models must be renewed, renew the fan, motor and shroud as a unit. The fan is separate from the shroud on later models. 23 Refitting is the reverse of removal. If the thermostatic switch was renewed, refill the cooling system.

5 Radiator, expansion tank

and coolant reservoir -

removal and refitting

Warning: Do not start this procedure until the engine is completely cool.

Radiator

Removal

1 Disconnect the negative battery cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Drain the coolant into a container (see Chapter 1). 3 Remove both the upper and lower radiator hoses, and the small expansion tank hose from the top left of the radiator (see illustration). 4 Remove the cooling fan and shroud (see Section 4).

3•4 Cooling, heating and air conditioning systems

4.20 Disconnect the fan’s electrical

connector (large arrow) and remove the

bolts (small arrows) on single-fan models -

grille is removed here

3261 Jaguar XJ6

4.15 Disconnect the electrical connector (A) from the

thermostatic switch (B) in the radiator and bypass it with a

jumper wire (C) - the fan should operate now with the ignition on

4.17 Disconnect the fan wiring connector and connect jumper wires from there directly to the positive and negative terminals of the battery - the purple wire’s terminal should receive the battery

power and the black wire’s terminal should be earthed

5 If equipped with an automatic transmission,

disconnect the cooler lines from the radiator (see illustrations). Disconnect the cooling fan switch connector (see illustration 4.15). Place a drip pan to catch the fluid and cap the fittings. Note: The transmission oil cooler lines

enter the radiator on the left, while the power steering cooler lines attach on the right side of the radiator. On 1993 and 1994 models, the cooler fittings require a spring-lock coupling tool, normally used on fuel lines or air conditioning lines.

6 Remove the four bolts from the radiator cowl panel and take off the panel (see

illustration). 7 Lift out the radiator. Be aware of dripping

fluids and the sharp fins. Take care not to damage the radiator fins by contact with other parts. 8 With the radiator removed, it can be inspected for leaks, damage and internal blockage. If repairs are necessary, have a radiator specialist or dealer service department perform the work, as special techniques are required. Check the rubber mounting pads on the bottom of the radiator (see illustration). If they’re cracked or damaged, get new ones before refitting the radiator. 9 Bugs and dirt can be cleaned from the radiator with compressed air and a soft brush. Don’t bend the cooling fins as this is done.

Warning: Wear eye protection.

Refitting

10 Refitting is the reverse of the removal

procedure. Be sure the rubber mounts are in place on the bottom of the radiator. 11 After refitting, fill the cooling system with the proper mixture of antifreeze and water. Refer to Chapter 1 if necessary. 12 Start the engine and check for leaks. Allow the engine to reach normal operating temperature, indicated by both radiator hoses becoming hot. Recheck the coolant level and add more if required. 13 On automatic transmission equipped models, check and add fluid as needed and check the power steering fluid level as well.

Expansion tank and coolant reservoir, removal and refitting

14 The expansion tank is located at the top of the left-hand side inner wing. With the cooling system drained below the level of the expansion tank, remove the hoses, the coolant level probe and the two screws mounting it to the body (see illustration). 15 Wash out and inspect the reservoir for cracks and chafing. Renew it if damaged.

16 If the low-coolant level light has been showing on the instrument panel, even when the coolant level is correct, disconnect the sensor’s connector and test it with an ohmmeter (see illustration). The sensor should be renewed if the resistance at the connections is over 150 ohms.

Caution: Using a long-necked funnel to add coolant can damage the sensor, which is just below the expansion tank filler neck.

Cooling, heating and air conditioning systems 3•5

5.5a At the left side of the radiator,

disconnect the automatic transmission

cooler lines (small arrows) and the lower

radiator hose (larger arrow)

5.5b Disconnect the power steering cooler lines (small arrows) at the right side of the

radiator, and the upper radiator hose

(large arrow)

3261 Jaguar XJ6

5.3 Remove the clamp and the hose going to the expansion tank

5.6 Remove the bolts (arrowed) and take off the radiator cowl panel

5.14 The expansion tank is located on the left inner wing

A Hose to recovery tank (where applicable) B Hose to radiator C Hose to thermostat housing D Hose to water pump housing E Mounting screws F Low-coolant-level sensor

5.8 There are rubber mounts (arrowed) for the radiator and the condenser -

they must be in place when these

components are reinstalled

5.16 The low-coolant-level sensor can be tested with an ohmmeter - resistance

should be below 150 ohms - gently use a

pair of long-neck pliers to move the sensor

up and down in the tank to get a reading

17 A coolant recovery bottle is used on 1988

and 1989 models, located in the passenger’s inner wing. The plastic inner wing splash shield must be removed for access to the recovery bottle (see Chapter 11). Disconnect the recovery hose and remove the mounting screws to renew the recovery bottle (see illustration). Models from 1990 on do not have the recovery bottle, but do have a larger expansion tank. 18 Refitting of either expansion tank or recovery bottle is the reverse of removal.

6 Engine oil cooler - renewal

1 Models from 1988 through 1991 have a engine oil cooler, mounted ahead of the radiator. The engine’s mechanical fan draws air through the oil cooler, cooling off hot engine oil that is circulated from the engine by steel tubes. Access to the cooler is with the grille removed (refer to Chapter 11 for grille removal). 2 To renew the oil cooler, first disconnect the

two fittings connecting the lines to the cooler (see illustration).

Caution: The engine should be cool for this procedure, and you should have a small drain pan handy because the fittings are on the bottom of the cooler and will probably drip some oil on dismantling.

3 Remove the mounting nuts to take the cooler out of the vehicle (see illustration). 4 The other ends of the oil cooler tubes mount to a block just below the oil filter. With a drain pan handy, remove the nut retaining both pipes to the block. 5 Refitting the oil cooler and oil lines is the reverse of removal. When refitting the lines to the block or the cooler, use new O-rings.

7 Water pump - check

1 A failure in the water pump can cause serious engine damage due to overheating. 2 With the engine running and warmed to normal operating temperature, squeeze the upper radiator hose. If the water pump is working properly, a pressure surge should be felt as the hose is released.

Warning: Keep hands away from fan blades!

3 Water pumps are equipped with weep or vent holes (see illustration). If a failure occurs in the pump seal, coolant will leak from this hole. In most cases it will be necessary to use a flashlight to find the hole on the water pump by looking through the space behind the pulley just below the water pump shaft. 4 If the water pump shaft bearings fail there may be a howling sound at the front of the engine while it is running. Bearing wear can be felt if the water pump pulley is rocked up and

down. Do not mistake drivebelt slippage, which causes a squealing sound, for water pump failure. Spray automotive drivebelt dressing on the belts to eliminate the belt as a possible cause of the noise.

8 Water pump and pipes -

renewal

Warning: Do not start this procedure until the engine is completely cool.

1 Disconnect the negative battery cable and drain the cooling system (see Chapter 1).

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Refer to Section 4 to remove the mechanical fan and clutch (if applicable to your model). 3 Refer to Chapter 1 for removal of the drivebelts.

3•6 Cooling, heating and air conditioning systems

6.3 Remove the mounting nuts (arrowed) to take the oil cooler out

7.3 Check the weep hole (arrowed) for signs of leakage (pump removed for

clarity) - grey discolouration is normal,

large brown stains indicates seal failure

3261 Jaguar XJ6

5.17 The recovery bottle (arrowed) on 1988 and 1989 models is located in the footwell - disconnect the hoses and the two

mounting screws

6.2 Disconnect the two metal oil lines (arrowed) where they mount to the bottom of the cooler - use two spanners

4 Remove the water pump mounting bolts (see illustration). Note 1: The water pump is sold as a complete

assembly, including the rear housing with the hose connections. Unless the rear housing is corroded or cracked, many Jaguar mechanics only refit the pump assembly itself, using the original rear housing with all its hoses intact. However, if the engine has a great deal of years or mileage on it, it would be a good idea to renew those hoses as well, in which case the new rear housing can be installed. Note 2: There are three different lengths of water pump bolts. The longer bolts retain the pump and rear housing to the engine (see

illustration 7.3). 5 If the pump doesn’t come loose right away,

tap it with a soft-faced hammer to break the gasket seal. Be careful not to hit the radiator fins with the pump during removal. 6 Thoroughly clean all sealing surfaces, removing all traces of gasket or sealant from the back of the pump and the face of the housing. 7 Apply a bead of RTV sealant to the sealing surface on the back of the pump. Refit the pump and bolts, tightening the bolts to the torque listed in this Chapter’s Specifications. 8 Refit the remaining parts in the reverse order of removal. Note: If the pump has been

renewed after many miles of usage, it’s a good idea to also renew the hoses connected to the water pump housing (see illustrations). Refer to Chapter 2A for intake manifold removal to access the coolant pipes and hoses. If you have noticed water leaks or stains on the left side of the engine, the leaks may be coming from these pipes and hoses.

9 Refill the cooling system (see Chapter 1), run the engine and check for leaks and proper operation.

9 Coolant temperature

sender unit - check and

renewal

Warning: Do not start this procedure until the engine is completely cool.

Check

1 If the coolant temperature gauge is inoperative, check the fuses first (Chapter 12). 2 If the temperature gauge indicates excessive temperature after running awhile, see the Fault finding section at the rear of the manual. 3 If the temperature gauge indicates Hot as soon as the engine is started cold, disconnect the wire at the coolant temperature sender (see illustration). If the gauge reading drops, renew the sender unit. If the reading remains high, the wire to the gauge may be shorted to ground, or the gauge is faulty. 4 If the coolant temperature gauge fails to show any indication after the engine has been warmed up, (approx. 10 minutes) and the fuses checked out OK, shut off the engine. Disconnect the wire at the sender unit and, using a jumper wire, connect the wire to a clean ground on the engine. Briefly turn on the ignition without starting the engine. If the gauge now indicates Hot, renew the sender unit. 5 If the gauge fails to respond, the circuit may be open or the gauge may be faulty - see Chapter 12 for additional information.

Renewal

6 Drain the coolant (see Chapter 1). 7 Disconnect the electrical connector from

the sender unit.

8 Using a deep socket or a spanner, remove the sender unit. 9 Refit the new unit and tighten it securely. Do not use thread sealant as it may electrically insulate the sender unit. 10 Reconnect the wiring connector, refill the cooling system and check for coolant leakage and proper gauge function.

10 Heating and air conditioning

blower motors - circuit check

and component renewal

Warning: Later models are equipped with airbags. To prevent accidental deployment

of the airbag, which could cause personal injury or damage to the airbag system, DO NOT work in the vicinity of the steering wheel or instrument panel. Jaguar recommends that, on airbag-equipped models, the following procedure should be left to a dealer service department or other repair workshop because of the special tools and techniques required to disable the airbag system.

1 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 There are two blower motors, one under the left side of the dash and one behind the glove compartment (see illustration). If the blower doesn’t work, check the fuse and all connections in the circuit for looseness and corrosion. Make sure the battery is fully charged. To access the right blower, remove the glove compartment liner, the glove compartment door and the right lower dash panel (see Chapter 11).

Warning: When working around

the area behind the glove box,

watch out for a strip of sheet

metal bracing that has a very sharp edge (see illustration). Apply some heavy duct tape to the edge of the brace before beginning work in this area, or you could injure your hands.

Cooling, heating and air conditioning systems 3•7

8.4 Remove the water pump mounting bolts (arrows indicate five visible here)

8.8a Once the water pump is removed, the rear housing (arrowed) is held in place only

by the hoses - check them for leakage and

condition whenever the pump is disturbed

8.8b The water pipe (arrowed) may need

new gaskets where it meets the block - the

pipe is best accessed from below or with

the intake manifold unbolted

9.3 The coolant temperature sender unit (arrowed) is located in the top of the

thermostat housing - it is the sender unit

with the single wire

3261 Jaguar XJ6

3 Remove the screws holding the cruisecontrol ECU in place (see illustrations), then remove the four screws holding the ECU mounting plate in place. 4 Disconnect the vacuum lines and electrical connectors at the blower housing, identifying each connection with marked masking tape for reassembly, or write down the colour codes of the vacuum tubing. Remove the duct tape connecting the blower housing to the duct from the heater/air conditioning unit. 5 Remove the two bolts holding the top of the blower housing to the cowl (see illustration). 6 Pull down and back on the housing until it

squeezes past the metal brace below it (see

illustration). It will take some force at first. 7 To access the left blower motor, remove

the left-hand brace rod from the steering column forward to the body (see illustration), then repeat Steps 4 and 5 on the left blower housing. The blower housing should now drop straight down and out. 8 If the blower motor does not operate, disconnect the electrical connectors at the blower motor and connect the black wire terminal to chassis ground, and the purple wire terminal to a fused source of battery voltage. If the blower doesn’t operate, it

should be renewed. If it does operate, there is a problem in the feed or earth circuit. 9 If the motor is good, but doesn’t operate at any speed, the problem could be in the heater/air conditioning control assembly or the heating/air conditioning computer. Diagnosis either of these electronic components is beyond the scope of the home mechanic, and should be referred to your Jaguar dealer or other qualified repair facility. 10 If either blower motor must be renewed, remove the five clips and one screw holding the blower housing halves together (see illustration).

3•8 Cooling, heating and air conditioning systems

10.2a The right blower housing (arrowed) is located behind the glove box area

of the dash

10.2b Apply heavy duct tape to the sharp edge of this brace (dotted line) when

working behind the glove box area of the

dash - the metal is very sharp

10.3a Remove the screw (A) holding the wiring harness in place, then remove the

two lower cruise-control ECU screws (B) . . .

10.3b . . . then remove the upper ECU

screw (arrowed) and pull down the ECU,

then remove the ECU mounting plate

10.5 Two bolts (arrow indicates the left bolt) hold the top of the blower housing

to the cowl

10.6 Pull down and out on the housing until it clears the sheet metal brace

below it

3261 Jaguar XJ6

10.7 Remove this brace rod (small arrow) for clearance to remove the left blower

motor housing (large arrow)

10.10 Remove the five clips (two shown

here with arrows) and one screw holding

the halves of the housing together

11 Separate the housing halves and pull up

the plastic plate holding the motor and fan (see illustration). The fan doesn’t come off the motor, but loosen the clamp-bolt on the motor’s mount bracket and slide the motor and fan out for renewal (see illustration).

Note: Some 1988 models had problems with cracking of the fan blades and noise from the blowers. These blowers and fans have been superseded with improved parts, available from your Jaguar dealer.

12 When either blower housing is separated, you’ll find two relays mounted inside (see illustration). These are the blower isolation relay and blower relay. Before refitting the blower housing in the car, refer to Chapter 12 for testing of these relays. 13 Refitting is the reverse of removal. Check for proper operation.

11 Heater core -

removal and refitting

Warning: Later model vehicles are equipped with airbags. To prevent the accidental deploy-

ment of the airbag, which could cause personal injury or damage to the airbag system, DO NOT work in the vicinity of the steering wheel or instrument panel. The manufacturer recommends that, on airbag-equipped models, the following procedure should be left to a dealer service department or other repair workshop because of the special tools and techniques required to disable the airbag system.

1 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Drain the cooling system (see Chapter 1). Disconnect the heater hoses where they enter the bulkhead (see illustration). Note: Use

compressed air in one of the pipes to blow out any remaining coolant and collect it. This will prevent any spills on the carpeting when the heater core is removed. Plug the pipes to

prevent any remaining coolant from spilling out. 3 Refer to Chapter 11 for removal of the under-dash panels on both the driver and passenger sides, and removal of the glovebox.

Warning: When working around the area behind the glove box, watch out for a strip of sheet

Cooling, heating and air conditioning systems 3•9

3261 Jaguar XJ6

10.11a Separate the housing halves - the blower motor (arrowed) is attached to a plastic plate sandwiched between the

two housing halves

10.11b Loosen the clamp bolt (arrowed) on the motor bracket and then pull the motor and fan out as an assembly

10.12 Inside the blower case are the blower and isolation relays (arrowed) - while the case is apart, test these relays for

proper operation

11.2 Disconnect the heater hoses from the pipes at the bulkhead (small arrows) - the large arrow indicates the evaporator case

retaining nut

metal bracing that has a very sharp edge (see illustration 10.2b). Apply some heavy duct tape to the edge of the brace before beginning work in this area, or you could injure your hands.

4 On the passenger’s side, under the dash, remove the screws holding the plastic cover where the heater pipes enter the heater/air conditioning housing (see illustration). 5 With the cover off, there is access to remove the four Allen bolts holding the two pipes to the heater core (see illustration). 6 Move to the right side and unbolt the climate control computer and pull it down and away from the heater/air conditioning housing

(see illustrations). 7 Remove the four small screws and remove

the plastic plate over the heater core, right behind where the climate control computer had been (see illustration). 8 Carefully slide the heater core out from the right side of the heating/air conditioning housing (see illustration). Note: Keep plenty

of towels or rags on the carpeting to catch any coolant that may drip.

9 Refitting is the reverse order of removal. When refitting the heater core, make sure all of the foam insulation strips are in place and refit new O-rings where the heater pipes enter the core (see illustration). 10 Refill the cooling system, reconnect the battery and run the engine. Check for leaks and proper system operation.

12 Heater and air conditioning

control assembly - check,

removal and refitting

Warning: Later models are equipped with airbags. To prevent the accidental deploy-

because of the special tools and techniques required to disable the airbag system.

Removal and refitting

1 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Refer to Chapter 11 for removal of the console heater control/radio assembly trim bezel. 3 Remove the mounting screws retaining the heater/air conditioning control assembly to the console (see illustrations). Pull the assembly out, and disconnect the electrical connectors.

3•10 Cooling, heating and air conditioning systems

11.4 Remove these screws (small arrows)

to remove the plastic plate over the heater

core pipes on the left side

11.5 With the cover off, remove the Allen

bolts (arrows indicate three of the four) to

pull the coolant pipes out of the left side of

the heater core

11.6a Remove three screws (one arrowed;

one at the top-back and one below) to take

out the climate-control computer on right

side of heater/air conditioning assembly

11.6b Pull away the climate control computer (arrowed)

11.7 Remove the four screws (arrowed) and the heater core cover plate

11.8 Pull the heater core out to the right

3261 Jaguar XJ6

11.9 Retain the original foam insulation on the heater core or transfer to the new

core, and replace the two O-rings

(arrowed)

12.3a Remove these six screws (arrowed) to release the control panel/radio

assembly from the console

4 Refitting is the reverse of the removal

procedure. 5 Run the engine and check for proper functioning of the heater (and air conditioning, if equipped).

Control checks

6 The climate-control system uses an allelectronic control panel that sends digital information to the climate control computer. There is little the home mechanic can do to troubleshoot or test the system. The factory recommends that diagnosis be performed at a dealership. 7 If there is a problem in just one area of climate control, put the controls through their entire range of operation and check the system responses, i.e. set the controls to COLD, the fan to low and the temperature to 65° F. In this mode the Manual LED should be lit and the air conditioning compressor should engage. Try all of the fan speeds and try the temperature on HOT, then feel for warm air coming from the ducts. Note: Between each

try of the different controls, wait 20 seconds or so for the heater/air conditioning system to adjust before checking for a response.

8 When each control button is pushed two times, its LED light should go on or off. Renew the control assembly if any of the warning lights don’t work. 9 On 1988 and 1989 models, if the climate controls do not respond to any driver input, check with your Jaguar dealer before renewing the ECU or control panel. A service part is available (a resistor, #JLM 1901) that can be installed at one of the control panel terminals that may fix the problem without any other parts being renewed. Instructions are included with the part. 10 Check the vacuum lines to the several vacuum motors that operate the heater/air conditioning functions. Look for pinched or blocked hoses and leaks.

11 Each of the vacuum “servo motors” in the system can be checked with a hand-held vacuum pump (see illustration). Apply vacuum and watch that the door or control it operates is working. 12 Further diagnosis of the controls or climate control ECU are best left to a Jaguar dealership or other qualified repair facility.

13 Air conditioning and heating

system - check and

maintenance

Air conditioning system

Warning: The air conditioning system is under high pressure. Do not loosen any hose fittings

or remove any components until the system has been discharged. Air conditioning refrigerant should be properly discharged into an EPA-approved recovery/recycling unit by a dealer service department or an automotive air conditioning repair facility. Always wear eye protection when working near air conditioning system fittings.

1 The following maintenance checks should be performed on a regular basis to ensure that the air conditioner continues to operate at peak efficiency:

a) Inspect the condition of the compressor

drivebelt. If it is worn or deteriorated, renew it (see Chapter 1).

b) Check the drivebelt tension and, if

necessary, adjust it (see Chapter 1).

c) Inspect the system hoses. Look for

cracks, bubbles, hardening and deterioration. Inspect the hoses and all fittings for oil bubbles or seepage. If there is any evidence of wear, damage or leakage, renew the hose(s).

d) Inspect the condenser fins for leaves,

bugs and any other foreign material that may have embedded itself in the fins. Use a “fin comb” or compressed air to remove debris from the condenser.

e) Make sure the system has the correct

refrigerant charge.

2 It’s a good idea to operate the system for about ten minutes at least once a month. This is particularly important during the winter months because long term non-use can cause hardening, and subsequent failure, of the seals. 3 Leaks in the air conditioning system are best spotted when the system is brought up to operating temperature and pressure, by running the engine with the air conditioning ON for five minutes. Shut the engine off and inspect the air conditioning hoses and connections. Traces of oil usually indicate refrigerant leaks. 4 Because of the complexity of the air conditioning system and the special equipment required to effectively work on it, accurate troubleshooting of the system should be left to a professional technician. 5 If the air conditioning system doesn’t operate at all, check the fuse panel and the air conditioning relay (refer to Chapter 12 for relay locations and testing). See Sections 4, 9 and 12 for electrical checks of heating/air conditioning system components. 6 The most common cause of poor cooling is simply a low system refrigerant charge. If a noticeable drop in cool air output occurs, the following quick check will help you determine if the refrigerant level is low.

Checking the refrigerant charge

7 Warm the engine up to normal operating temperature. 8 Place the air conditioning temperature selector at the coldest setting and put the

Cooling, heating and air conditioning systems 3•11

3261 Jaguar XJ6

12.3b Remove the four screws (three are shown here) holding the control assembly in the control/radio housing

12.11 Check the operation of the vacuum servo motors; in this case, vacuum is applied to the servo on the right blower case -

the flapper door (arrowed) should operate

blower at the highest setting. Open the doors (to make sure the air conditioning system doesn’t cycle off as soon as it cools the passenger compartment). 9 With the compressor engaged - the clutch will make an audible click and the centre of the clutch will rotate. After the system reaches operating temperature, feel the two pipes connected to the evaporator at the bulkhead

(see illustration). 10 The pipe (thinner tubing) leading from the

condenser outlet to the evaporator should be cold, and the evaporator outlet line (the thicker tubing that leads back to the compressor) should be slightly colder (3 to 10° F). If the evaporator outlet is considerably warmer than the inlet, the system needs a charge. Insert a thermometer in the centre air distribution duct while operating the air conditioning system - the temperature of the output air should be 35 to 40° F below the ambient air temperature (down to approximately 40° F). If the ambient (outside) air temperature is very high, say 110° F, the duct air temperature may be as high as 60° F, but generally the air conditioning is 30 to 50° F cooler than the ambient air. If the air isn’t as cold as it used to be, the system probably needs a charge. Further inspection or testing of the system is beyond the scope of the home mechanic and should be left to a professional. 11 Inspect the sight glass (see illustration). If the refrigerant looks foamy when running, it’s low. When ambient temperatures are very hot, bubbles may show in the sight glass even with the proper amount of refrigerant. With the proper amount of refrigerant, when the air conditioning is turned off, the sight glass should show refrigerant that foams, then clears. Note: 1993 and 1994 models are

equipped with R-134a refrigerant systems and do not have a sight glass.

Heating systems

12 If the air coming out of the heater vents isn’t hot, the problem could stem from any of the following causes:

a) The thermostat is stuck open, preventing

the engine coolant from warming up enough to carry heat to the heater core. Renew the thermostat (see Section 3).

b) A heater hose is blocked, preventing the

flow of coolant through the heater core. Feel both heater hoses at the bulkhead. They should be hot. If one of them is cold, there is an obstruction in one of the hoses or in the heater core, or the heater control valve is shut. Detach the hoses and back flush the heater core with a water hose. If the heater core is clear but circulation is impeded, remove the two hoses and flush them out with a water hose.

c) If flushing fails to remove the blockage

from the heater core, the core must be renewed. (see Section 11).

13 If the blower motor speed does not correspond to the setting selected on the blower switch, the problem could be a bad

fuse, circuit, control panel or climate control computer (see Sections 10 and 12). 14 If there isn’t any air coming out of the vents:

a) Turn the ignition ON and activate the fan

control. Place your ear at the heating/air conditioning register (vent) and listen. Most motors are audible. Can you hear the motor running?

b) If you can’t (and have already verified that

the blower switch and the blower motor resistor are good), the blower motor itself is probably bad (see Section 10).

15 If the carpet under the heater core is damp, or if antifreeze vapour or steam is coming through the vents, the heater core is leaking. Remove it (see Section 11) and refit a new unit (most radiator shops will not repair a leaking heater core). 16 Inspect the drain hose from the heat/AC assembly at the right side of the bulkhead, make sure it is not clogged (see illustration). If there is a humid mist coming from the system ducts, this hose may be plugged. In some early models, the hose may have been pinched during assembly or blocked with insulation or underseal.

14 Air conditioning

receiver/drier -

removal and refitting

Warning: The air conditioning system is under high pressure. Do not loosen any hose fittings

or remove any components until the system has been discharged. Air conditioning refrigerant should be properly discharged into an EPA-approved recovery/ recycling unit by a dealer service department or an automotive air conditioning

3•12 Cooling, heating and air conditioning systems

13.16 This drain hose (arrowed) from the

heater/air conditioning unit should be kept

clear to allow drainage of condensation

3261 Jaguar XJ6

13.9 Feel the inlet (small arrow) and outlet (large arrow) pipes at the bulkhead leading to the air conditioning evaporator (battery

removed here for clarity only)

13.11 The sight glass (arrowed) is located on the top of the receiver/drier, to the right of the radiator

repair facility. Always wear eye protection when working near air conditioning system fittings.

1 Have the refrigerant discharged and recovered by an air conditioning technician.

2 Disconnect the refrigerant lines (see illustration) from the receiver/drier and cap

the open fittings to prevent entry of moisture. 3 Remove the three nuts holding the receiver/drier to the radiator support and remove the receiver/drier. Note: On 1993 and

1994 models, the receiver/drier is a long tubular style mounted to the top-front of the radiator support. The grille must be removed for access on these models (see Chapter 11

for grille removal).

4 Refitting is the reverse of removal. 5 Have the system evacuated, charged and

leak tested by the workshop that discharged it. If the receiver/drier was renewed, have them add new refrigeration oil to the compressor, about 28 cc (one ounce). Use only the refrigerant oil compatible with the refrigerant of your system (R-12 or R-134a).

15 Air conditioning

compressor -

removal and refitting

Warning: The air conditioning system is under high pressure. Do not loosen any hose fittings

1 Have the refrigerant discharged by an automotive air conditioning technician.

2 Disconnect the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

3 Remove the drivebelt from the compressor (see Chapter 1). 4 Detach the electrical connector and disconnect the flexible refrigerant lines (see

illustration). 5 Unbolt the compressor and lift it from the vehicle (see illustration). 6 If a new or rebuilt compressor is being

installed, drain the fluid from the new unit by opening the drain plug and by tilting the compressor to the rear so that any remaining oil will come out the ports in the back normally covered by the plate and hard lines. Refit the drain plug and end-plate and add 199 cc (7 fluid ounces) of new oil of a type compatible with the type refrigerant in your system. 7 Refitting is the reverse of removal. Renew any O-rings with new ones specifically made for the type of refrigerant in your system and lubricate them with refrigerant oil, also designed specifically for your refrigerant. 8 Have the system evacuated, recharged and tested by the workshop that discharged it.

16 Air conditioning condenser -

removal and refitting

Warning: The air conditioning system is under high pressure. Do not loosen any hose fittings

1 Have the refrigerant discharged and recovered by an air conditioning technician. 2 Remove the radiator cowl panel as described in Section 5. 3 Using two spanners to avoid twisting the fittings, disconnect the inlet and outlet lines from the condenser (see illustration). 4 Pull the condenser straight up and out of the vehicle. 5 Refitting is the reverse of removal. When refitting the condenser, be sure the rubber

Cooling, heating and air conditioning systems 3•13

15.5 Remove the lower mounting bolts and the adjuster bolt (arrowed)

16.3 Disconnect the two lines, then pull up on the condenser (arrowed)

3261 Jaguar XJ6

14.2 After the system has been discharged, unbolt the two

refrigerant lines (left arrows) from the top of the receiver/drier and

cap them - use two spanners when loosening or tightening these

lines - right arrows indicate the two top mounting bolts

15.4 Disconnect the electrical connector (small arrow) at the compressor, then disconnect the bolt (large arrow) at the

retaining plate that holds the two hoses in place

cushions fit on the mounting points and that any foam insulator strips are still in place or transferred to the new condenser. 6 Reconnect the refrigerant lines, using new O-rings. If a new condenser has been installed, add 84 cc (3 fluid ounces) of new refrigerant oil. Note: The oil and O-rings must

be compatible with the type of refrigerant you are using.

7 Refit the remaining parts in the reverse order of removal. 8 Have the system evacuated, charged and leak tested by the workshop that discharged it.

17 Air conditioning evaporator

and expansion valve -

removal and refitting

Warning 1: The air conditioning system is under high pressure. Do not loosen any hose fittings

conditioning repair facility. Always wear eye protection when disconnecting air conditioning system fittings.

Warning 2: Later model vehicles are equipped with airbags. To prevent the accidental

deployment of the airbag, which could cause personal injury or damage to the airbag system, DO NOT work in the vicinity of the steering wheel or instrument panel. The manufacturer recommends that, on airbag-equipped models, the following procedure should be left to a dealer service department or other repair workshop because of the special tools and techniques required to disable the airbag system.

1 Refer to Chapter 11 for removal of the glove compartment, under-dash panels and console. Note: The removal of the

heater/evaporator housing is difficult and time-consuming, much more so than the removal of the heater core (see Section 11). For some home mechanics, the job is better left to a Jaguar dealership or other qualified repair workshop.

2 Disconnect the air conditioning lines from the backside of the expansion valve (at the bulkhead, just to the right of the engine), using

two spanners (see illustration). Cap the open fittings and expansion valve after dismantling to prevent the entry of air or dirt. 3 Refer to Section 11 for moving the climatecontrol computer aside and disconnecting the heater core pipes. 4 From the engine side of the bulkhead, near the expansion valve, remove the nut retaining the heat/air conditioning assembly housing (see illustration). Another mounting nut is on the left side, under the wiper motor (see

illustration 11.2). 5 Disconnect the defroster ducts on the left and right side of the evaporator housing (see illustration). 6 Identify all of the vacuum motor lines with

masking tape and a felt pen, then disconnect the lines. Note: Most vacuum lines are colour-

coded. Make notes on which ones go to which devices.

7 Tag and disconnect the wiring plugs connected to the heating/air conditioning housing. 8 At the bottom left and bottom right of the housing, pull off the rubber drain tubes that go into the flooring. 9 Remove the four rod-type support braces. Two support the dash, and two connect the case to the floor of the car (see illustrations).

3•14 Cooling, heating and air conditioning systems

17.5 Left duct (large arrow) can be removed by pulling off the clip (small arrow) - right

duct pulls out without a clip

17.9a Unbolt the four support braces

(small arrows) from the case (large arrow)

and floor

17.9b Black case-support rods are held

with nuts (arrowed), the gold dash-support

rods are retained by a bolt/nut to the dash

3261 Jaguar XJ6

17.2 Use two spanners when disconnecting the air conditioning

lines (arrowed) at the bulkhead, on the backside of the expansion

valve - one spanner holds the body of the expansion valve

17.4 Remove the housing retaining nut (arrowed) on the engine

side of the bulkhead, near the expansion valve - another nut is on

the right, near the heater core pipes

10 With everything disconnected, pull the

heat-air conditioning housing back and out from under the dash.

Caution: Do not force anything. If the unit gets stuck, determine where the interference is before a duct, wire or hose is broken.

11 Pry off the series of black metal clips connecting the main housing to the evaporator case, then separate the evaporator case and pull out the evaporator core. Note: When

refitting the evaporator core into the case, be sure to refit the foam insulation in the same way it was installed originally.

12 The evaporator core can be cleaned with a “fin comb” and blown off with compressed air.

13 The expansion valve is located on the right side of the bulkhead on the engine side. To renew it, remove the battery (Chapter 5) for better access. Disconnect the lines from the back of the valve as in Step 2. Disconnect the high and low-pressure hoses from the front of the expansion valve (see illustration). 14 If the evaporator core is renewed, make sure the technician adds 1.4 ounces of new refrigerant oil (of a type compatible with your type of refrigerant) to the system. 15 The remainder of the refitting is the reverse of the removal process. Be sure to use new O-rings, and new gaskets on the expansion valve. 16 Have the system evacuated, charged and leak tested by the workshop that discharged it.

Cooling, heating and air conditioning systems 3•15

17.13 Disconnect the lines at the front of the expansion valve - always use two

spanners to avoid twisting a line - one

spanner holds the body of the valve

3261 Jaguar XJ6

Chapter 4

Fuel and exhaust systems

Fuel system

Fuel pressure: kPa psi

Ignition ON, engine not running . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 to 300 38 to 44

Engine idling:

Vacuum hose detached from fuel pressure regulator . . . . . . . . . . . 280 to 320 40 to 46

Vacuum hose attached to fuel pressure regulator . . . . . . . . . . . . . 210 to 260 30 to 38

Fuel system hold pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 21

Fuel injector resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 to 3.0 ohms

Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Must be set by authorised service department

Torque wrench settings Nm lbf ft

Throttle body mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 14

Fuel rail mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 9

Accelerator cable - removal, refitting and adjustment . . . . . . . . . . . 10

Air cleaner assembly - removal and refitting . . . . . . . . . . . . . . . . . . . 9

Catalytic converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6

CHECK ENGINE light . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6

Electronic Fuel Injection (EFI) system - check . . . . . . . . . . . . . . . . . . 12

Electronic Fuel Injection (EFI) system - component check

and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Electronic Fuel Injection (EFI) system - general information . . . . . . . 11

Exhaust manifold - removal and refitting . . . . . . . . . . . See Chapter 2A

Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Exhaust system servicing - general information . . . . . . . . . . . . . . . . 14

Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Fuel level sender unit - check and renewal . . . . . . . . . . . . . . . . . . . . 5

Fuel lines and fittings - inspection and renewal . . . . . . . . . . . . . . . . 6

Fuel pressure relief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Fuel pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Fuel pump/fuel pressure - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Fuel system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Fuel tank cap gasket renewal . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Fuel tank cleaning and repair - general information . . . . . . . . . . . . . 8

General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Intake manifold - removal and refitting . . . . . . . . . . . . See Chapter 2A

Underbonnet hose check and renewal . . . . . . . . . . . . . . See Chapter 1

4•1

Specifications

Contents

Easy, suitable for

novice with little experience

Fairly easy, suitable for beginner with some experience

Fairly difficult,

suitable for competent DIY mechanic

Difficult, suitable for experienced DIY mechanic

Very difficult,

suitable for expert DIY or professional

Degrees of difficulty

1 General information

The fuel system consists of a fuel tank, an electric fuel pump either located externally, next to the fuel tank (1988 to 1990 models) or in the fuel tank (1991 to 1994 models), an EFI fuel pump relay and main relay, an inertia switch, fuel injectors and fuel rail, an air cleaner assembly and a throttle body unit.

Multi Point Fuel Injection (MPFI) system

Multi point fuel injection uses timed impulses to sequentially inject the fuel directly into the intake port of each cylinder. The

injectors are controlled by the Electronic Control Unit (ECU). The ECU monitors various engine parameters and delivers the exact amount of fuel, in the correct sequence, into the intake ports. The throttle body serves only to control the amount of air passing into the system. Because each cylinder is equipped with an injector mounted immediately adjacent to the intake valve, much better control of the fuel/air mixture ratio is possible.

Fuel pump and lines

Fuel is circulated from the fuel tank to the fuel injection system, and back to the fuel tank, through a pair of metal lines running along the underside of the vehicle. On early models (1988 to 1990), an electric fuel pump is attached to the chassis next to the fuel

tank. On later models (1991 to 1994), the fuel pump and fuel level sender unit are located inside the fuel tank. A vapour return system routes all vapours and hot fuel back to the fuel tank through a separate return line.

The fuel pump will operate as long as the engine is cranking or running and the ECU is receiving ignition reference pulses from the electronic ignition system (see Chapter 5). If there are no reference pulses, the fuel pump will shut off after 2 or 3 seconds.

Inertia switch

These models are equipped with an inertia switch that is wired in the circuit between the fuel pump relay, the ignition switch and the fuel pump (refer to the wiring diagrams at the end of Chapter 12). The inertia switch is a

special electrical device that provides circuit protection by switching off the ignition and fuel pump upon impact in the event of vehicle collision. Later Jaguar models are equipped with an additional specialised inertia switch. This later device switches OFF all ignition fed circuits, locks the fuel filler cap, locks the boot (only if doors are locked) and unlocks the doors if they are locked during the accident. All these functions are directed by the inertia switch. The inertia switch is located behind the left kick panel. Refer to Chapter 12 for more information.

Exhaust system

The exhaust system includes an exhaust manifold equipped with an exhaust oxygen sensor, a catalytic converter, an exhaust pipe, and a silencer.

The catalytic converter is an emission control device added to the exhaust system to reduce pollutants. A single-bed converter is used in combination with a three-way (reduction) catalyst. See Chapter 6 for more information regarding the catalytic converter.

2 Fuel pressure relief

Warning: Petrol is extremely flammable, so take extra precautions when you work on

any part of the fuel system. Don’t smoke or allow open flames or bare light bulbs near the work area, and don’t work in a garage where a natural gas-type appliance (such as a water heater or a clothes dryer) with a pilot light is present. Since petrol is carcinogenic, wear latex gloves when there’s a possibility of being exposed to fuel, and, if you spill any fuel on your skin, rinse it off immediately with soap and water. Mop up any spills immediately and do not store fuel-soaked rags where

they could ignite. The fuel system is under constant pressure, so, if any fuel lines are to be disconnected, the fuel pressure in the system must be relieved first. When you perform any kind of work on the fuel system, wear safety glasses and have a Class B type fire extinguisher on hand.

1 Before servicing any fuel system component, you must relieve the fuel pressure to minimise the risk of fire or personal injury. 2 Remove the fuel filler cap - this will relieve any pressure built up in the tank. 3 Remove the fuel pump relay from the main relay panel (see illustrations). Note: These

models are equipped with a fuel pump relay that is located in various areas of the vehicle depending on the year. On 1988 and 1989 models, the fuel pump relay is under the glovebox. On 1990 to 1992 models, the fuel pump relay is in the engine compartment on the left side, attached to the brake pedal hanger. On 1993 models, the fuel pump relay is in the boot. On 1994 models, it’s in the engine compartment on the right side of the bulkhead. Refer to the relay location charts in Chapter 12 for additional information.

4 Start the engine and wait for the engine to stall, then turn the ignition key to Off. Disconnect the cable from the negative

terminal of the battery before beginning any work on the fuel system.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

5 The fuel system is now depressurised. Note: Place a rag around the fuel line before

removing any hose clamp or fitting to prevent any residual fuel from spilling onto the engine.

3 Fuel pump/fuel pressure -

check

Warning: Petrol is extremely flammable, so take extra precautions when you work on any part of the fuel system. See

the Warning in Section 2.

Note: To perform the fuel pressure test, you will need to obtain a fuel pressure gauge and adapter set (fuel line fittings). Note: On 1988 to 1990 models, the fuel pump may chatter excessively and the engine may stall frequently during hot weather. If stalling occurs, the engine will restart after a cooldown period. Dual fuel pumps can be installed by a dealer service department or other qualified repair facility to remedy this problem.

Preliminary inspection

1 Should the fuel system fail to deliver the proper amount of fuel, or any fuel at all, inspect it as follows. Remove the fuel filler cap. Have an assistant turn the ignition key to the ON position (engine not running) while you listen at the fuel filler opening. You should hear a whirring sound that lasts for a couple of seconds. On 1988 to 1990 models, listen behind the left rear wheel (external fuel pump) for the fuel pump sound. 2 If you don’t hear anything, check the fuel pump relay (see illustration 2.3a, b or c) and

4•2 Fuel and exhaust systems

2.3c On 1992 models, the fuel pump relay is located in the left rear corner of the

engine compartment

3261 Jaguar XJ6

2.3a Relay locations on a 1988 model

2.3b Relay locations on a 1989 model

circuit. If all circuits are intact and not damaged, check the inertia switch. Note: The

inertia switch is a special device that shuts down power to the ignition and the fuel pump in the event of an accident. See Chapter 12 for checking and resetting procedures for the inertia switch.

3 Remove the relay and check for battery voltage to the fuel pump relay connector (see illustration). If there is battery voltage present, check the relay for proper operation. Refer to the relay checking procedure in Chapter 12. Note: If battery voltage is not

available, check for battery voltage to the main relay (see illustration). Refer to the relay location diagrams in Chapter 12. The main relay, which is located next to the fuel pump relay, supplies voltage to the fuel pump and ignition system.

4 If battery voltage is present, check for battery voltage directly at the fuel pump electrical connector (see illustrations), within two seconds of the ignition key being turned On. If there is no voltage, check the fuel pump circuit. If there is voltage present, renew the pump (see Section 4). Note: It will be

necessary to raise the vehicle and support it securely on axle stands to gain access to the fuel pump electrical connectors. Have an assistant operate the ignition key and be sure to block the front wheels to avoid any movement of the vehicle.

Operating pressure check

5 Relieve the fuel system pressure (see Section 2). Detach the cable from the negative battery terminal.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

6 Detach the fuel line from the fuel rail and connect a fuel pressure gauge (see illustrations) between the fuel pulsation

damper and the fuel rail. Tighten the hose clamps securely. 7 Attach the cable to the negative battery terminal. Start the engine. 8 Note the fuel pressure and compare it with the pressure listed in this Chapter’s Specifications. 9 Disconnect the vacuum hose from the fuel

pressure regulator and hook up a hand-held vacuum pump (see illustration) to the port on the fuel pressure regulator. 10 Read the fuel pressure gauge with vacuum applied to the pressure regulator and also with no vacuum applied. The fuel pressure should decrease as vacuum increases (and increase as vacuum decreases).

Fuel and exhaust systems 4•3

3261 Jaguar XJ6

3.3a Checking for battery voltage at the fuel pump relay connector ( 1989 model)

3.3b Checking for battery voltage to the main relay (1989 model)

3.6a Remove the fuel line from the fuel pulsation damper . . .

3.4b Check for battery voltage to the

fuel pump on the harness connector near

the fuel tank on models with in-tank

fuel pumps

3.4a Remove the rubber boot from the fuel pump electrical connector and check for

voltage while an assistant turns the

ignition key (1989 model shown)

3.6b . . . then refit the fuel pressure gauge between the fuel rail and the fuel pressure

damper using a T-fitting

11 Reconnect the vacuum hose to the

regulator and check the fuel pressure at idle, comparing your reading with the value listed in this Chapter’s Specifications. Disconnect the vacuum hose and watch the gauge - the pressure should jump up considerably as soon as the hose is disconnected. If it doesn’t, check for a vacuum signal to the fuel pressure regulator (see Step 14). 12 If the fuel pressure is low, pinch the fuel return line shut (see illustration) and watch the gauge. If the pressure doesn’t rise, the fuel pump is defective or there is a restriction or leak in the fuel feed line, or the pump is faulty. If the pressure rises sharply, renew the pressure regulator. 13 If the fuel pressure is too high, turn the engine off. Disconnect the fuel return line and blow through it to check for a blockage. If there is no blockage, renew the fuel pressure regulator. 14 Connect a vacuum gauge to the pressure regulator vacuum hose. Start the engine and check for vacuum (see illustration). The fuel pressure regulator receives manifold vacuum that decreases (increases fuel pressure) when the engine speed is raised (acceleration). If there isn’t vacuum present, check for a clogged hose or vacuum port. If the amount of

vacuum is adequate but the pressure is too high, renew the fuel pressure regulator. 15 Turn the ignition switch to OFF, wait five minutes and recheck the pressure on the gauge. Compare the reading with the specified hold pressure. If the hold pressure is less than specified:

a) The fuel lines may be leaking. b) The fuel pressure regulator may be

allowing the fuel pressure to bleed through to the return line.

c) A fuel injector (or injectors) may be

leaking.

d) The fuel pump may be defective.

4 Fuel pump -

removal and refitting

Warning: Petrol is extremely flammable, so take extra precautions when you work on any part of the fuel system. See

the Warning in Section 2.

Note 1: On early models (1988 to 1990), an electric fuel pump is attached to the chassis next to the fuel tank. On later models (1991 to

1994), the fuel pump is inside the fuel tank. Note 2: On 1988 to 1990 models, the fuel pump may chatter excessively and the engine may stall frequently during hot weather. If stalling occurs, the engine will restart after a cool-down period. Dual fuel pumps can be installed by a dealer service department or other qualified repair facility to remedy this problem.

1 Remove the fuel tank filler cap to relieve any pressure in the fuel tank. Relieve the fuel pressure (see Section 2). 2 Disconnect the cable from the negative terminal of the battery.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

External fuel pumps

3 Raise the vehicle and support it securely on axle stands.

4 Disconnect the fuel lines from the fuel pump. 5 Disconnect the electrical connectors from the fuel pump (see illustration 3.4a). 6 Remove the fuel pump bracket retaining nuts (see illustration). 7 Carefully withdraw the fuel pump from the

rubber case inside the fuel pump bracket and angle the fuel pump over the rear suspension and out near the wheel on the left side of the vehicle. 8 Refitting is the reverse of removal.

In-tank fuel pumps

9 Raise the vehicle and support it securely on axle stands. 10 Disconnect the fuel pump and fuel level sender unit electrical connectors and the fuel lines. 11 Remove the fuel tank from the boot (see Section 7). 12 Disconnect the fuel lines from the evaporative flange (see illustration). Remove the lock ring with a hammer and brass punch, tapping the lock ring anti-clockwise. 13 Withdraw the fuel pump module from the fuel tank. Note: The fuel pump module is

4•4 Fuel and exhaust systems

3.14 Connect a vacuum gauge to the vacuum line leading to the fuel pressure regulator and check the vacuum source

4.6 Remove the fuel pump mounting nuts (arrowed) and slide the fuel pump out of

the rubber casing (1989 model shown)

3261 Jaguar XJ6

3.9 Check fuel pressure without vacuum applied to the fuel

pressure regulator, then with vacuum applied; fuel pressure

should DECREASE as vacuum INCREASES

3.12 Using a pair of pliers, squeeze the return line and observe

the fuel pressure increase (wrap a rag around the fuel line so you

don’t damage it)

indexed near the bottom, therefore it will be necessary to turn the module slightly to unlock it from the rubber holder mounted on the bottom of the fuel tank.

14 Renew the fuel pump module as a single unit.

15 Refitting is the reverse of removal.

5 Fuel level sender unit - check

and renewal

Warning: Petrol is highly flammable, so take precautions when you work on any part of the fuel system. See the Warning in Section 2.

Note: Some 1994 models may be equipped with faulty fuel level sender units. A tight float rod bushing may cause the float to stick and indicate high fuel levels while the tank is almost empty.

Check

1 Before performing any tests on the fuel level sender unit, completely fill the tank with fuel. 2 Remove the boot liner (see Chapter 12) to expose the fuel level sender unit access cover. 3 Disconnect the fuel level sender unit electrical connector located on the access

cover. Note: 1991 to 1994 models are

equipped with a fuel pump module and a sender unit assembly while 1988 and 1989 models are equipped with only the fuel level sender unit inside the tank.

4 Position the ohmmeter probes on the electrical connector terminals (see illustration) and check for resistance. Use the 200 ohm scale on the ohmmeter. 5 With the fuel tank completely full, the resistance should be about 18 to 20 ohms. 6 Reconnect the electrical connector and drive it until the tank is nearly empty. 7 Check the resistance. The resistance of the sender unit should be about 190 to 200 ohms.

8 If the readings are incorrect, renew the sender unit. Note: The test can also be

performed with the fuel level sender unit removed from the fuel tank. Using an ohmmeter, check the resistance of the sender unit with the swing arm completely down (tank empty) and with the arm up (tank full) (see illustration). The resistance should change steadily from 200 ohms to around 18 ohms.

Renewal

Warning: The fuel level in the tank must be less than half full to safely remove the fuel

pump/sender unit assembly from the fuel

Fuel and exhaust systems 4•5

5.4 Connect the probes of the ohmmeter

to the fuel level sender unit terminals and

check the resistance of the float assembly

5.8 An accurate check of the sender unit

can be made by removing it from the fuel tank and observing the resistance with the float down (empty) and then extended (full)

3261 Jaguar XJ6

4.12 Exploded view of the in-

tank fuel pump and the fuel tank

on 1991 to 1994 models

tank. If there is any doubt about the amount of fuel in the tank, drain the fuel tank completely before attempting this procedure (Section 7, paragraph 1).

9 Disconnect the cable from the negative terminal of the battery. Disconnect the fuel level sender unit/fuel pump electrical connector.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

10 Using a brass punch, tap on the lock ring anti-clockwise (see illustration) until the tabs align with the indentations in the fuel tank. 11 Carefully angle the sender unit out of the opening without damaging the fuel level float

(see illustration). 12 Refitting is the reverse of removal.

6 Fuel lines and fittings -

inspection and renewal

Warning: Petrol is extremely flammable, so take extra precautions when you work on any part of the fuel system. See the Warning in Section 2.

Note: If there is a distinct knocking noise coming from the dash when the engine is idling, the fuel feed hose may have hardened, restricting fuel flow and causing abnormal sounds. Replace the fuel inlet (feed) hose with a new one.

Inspection

1 Once in a while, you will have to raise the vehicle to service or renew some component (an exhaust pipe hanger, for example). Whenever you work under the vehicle, always inspect fuel lines and all fittings and connections for damage or deterioration. 2 Check all hoses and pipes for cracks, kinks, deformation or obstructions. 3 Make sure all hoses and pipe clips attach their associated hoses or pipes securely to the underside of the vehicle.

4 Verify all hose clamps attaching rubber hoses to metal fuel lines or pipes are a tight fit between the hoses and pipes.

Renewal

5 If you must renew any damaged sections, use hoses or pipes constructed from exactly the same material as the section you are replacing. Do not refit substitutes constructed from inferior or inappropriate material or you could cause a fuel leak or a fire. 6 Always, before detaching or disassembling any part of the fuel line system, note the routing of all hoses and pipes and the orientation of all clamps and clips to assure that new sections are identically installed. 7 Before detaching any part of the fuel system, be sure to relieve the pressure in the tank by removing the fuel tank cap, then relieve the fuel system pressure (Section 2). Cover the fitting being disconnected with a rag to absorb any fuel that may leak out.

7 Fuel tank -

removal and refitting

Warning: Petrol is extremely flammable, so take extra precautions when you work on

any part of the fuel system. See the Warning in Section 2.

1 This procedure is much easier to perform if the fuel tank is empty. Some models may have a drain plug for this purpose. If for some reason the drain plug can’t be removed, postpone the job until the tank is empty or siphon the fuel into an approved container using a siphoning kit (available at most motor factors).

Warning: Do not start the siphoning action by mouth!

2 Remove the fuel filler cap to relieve fuel tank pressure. 3 Detach the battery negative cable.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

4 If the tank is full or nearly full, drain the fuel into an approved container. 5 Raise the vehicle and place it securely on axle stands.

6 Remove the filler neck vent tube clamp (see illustration) and separate the tube from the

fuel filler neck.

7 Remove the fuel filler assembly bolts (see illustration) and slide the large rubber boot

down the neck of the fuel tank. Note: These vehicles are susceptible to clogging of the fuel overflow line. If this happens, excess fuel or

4•6 Fuel and exhaust systems

7.6 Remove the clamp that retains the fuel filler assembly to the filler neck

7.7a Remove bolts (arrowed) that retain the fuel filler assembly to the body and slide the

assembly down the filler neck of fuel tank

3261 Jaguar XJ6

5.10 Use a brass punch and remove the lock ring by tapping on it in an anti-clockwise direction

5.11 Lift the fuel level sender unit assembly from the fuel tank at an angle so as not to damage the float or arm

water in the fuel filler cap recess could flow into the boot, causing a dangerous condition and/or an unpleasant mess. To correct this condition, direct low-pressure compressed air into the overflow hole (see illustration), which should be enough to clear any obstruction in the line.

8 Remove the spare tyre and the spare tyre bracket assembly (see illustration). 9 Disconnect the fuel lines, the vapour return line and the canister vent line (see

illustrations). Note: Be sure to plug the hoses to prevent leakage and contamination of the fuel system. Remove the driveline to gain

access to the fuel line connectors next to the tank (see Chapter 8). Working under the vehicle, remove the pins using a needle-nose pliers, turn the connectors slightly to loosen them from the grommets and pull the fuel lines out of the tank.

10 Remove the retaining bolts from the fuel tank retaining straps (see illustration). 11 Pull the fuel tank out into the boot area.

Be careful to angle the fuel filler neck away from the body.

12 Remove the tank from the vehicle. 13 Refitting is the reverse of removal.

8 Fuel tank cleaning

and repair -

general information

1 Any repairs to the fuel tank or filler neck should be carried out by a professional who has experience in this critical and potentially dangerous work. Even after cleaning and flushing of the fuel system, explosive fumes can remain and ignite during repair of the tank. 2 If the fuel tank is removed from the vehicle, it should not be placed in an area where sparks or open flames could ignite the fumes coming out of the tank. Be especially careful inside garages where a natural petrol-type appliance is located, because the pilot light could cause an explosion.

9 Air cleaner assembly -

removal and refitting

1 Detach the clips and remove the air filter cover and the filter element (see Chapter 1). 2 Remove the bolts and remove the air cleaner assembly from the engine compartment (see

illustrations). 3 Refitting is the reverse of removal.

Fuel and exhaust systems 4•7

7.7b Direct low pressure compressed air

into the hole for the overflow line if clogged

7.8 Remove the bolts (arrowed) from the

spare tyre bracket and lift out the assembly

7.9a Disconnect the flexible fuel lines from the metal fuel lines

7.9b Disconnect the vapour return line from the fuel tank

7.9c Disconnect the canister purge line from the fuel tank

7.9d Remove the clips (arrowed) that

retain the fuel lines to the fuel tank using

needle-nose pliers

3261 Jaguar XJ6

7.10 Remove the tank strap bolts (arrowed) from the body

9.2a Remove the bolts (arrowed) from the air cleaner assembly

9.2b Also, remove the bolt that retains the air intake duct to the MAF sensor and lift

the assembly from the compartment

10 Accelerator cable - removal,

refitting and adjustment

Removal

1 Detach the cable from the negative terminal of the battery.

Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

2 Loosen the locknut on the threaded portion of the throttle cable at the throttle body (see

illustration). 3 Rotate the throttle lever, then slip the

throttle cable end out of the slot in the lever

(see illustration). 4 Detach the throttle cable from the accelerator pedal (see illustration). 5 From inside the vehicle, pull the cable

through the bulkhead.

Refitting and adjustment

6 Refitting is the reverse of removal. 7 To adjust the cable, fully depress the

accelerator pedal and check that the throttle is fully opened. 8 If not fully opened, loosen the locknuts, depress accelerator pedal and adjust the cable until the throttle is fully open. 9 Tighten the locknuts and recheck the adjustment. Make sure the throttle closes fully when the pedal is released (see illustration). 10 After the cable is adjusted, check the adjustment of the bellcrank. Use a small clamp and a straight rod or stiff wire (coat hanger) and attach it to the brake master cylinder in such a way that the tip acts as a pointer. Align the pointer with “A” (automatic transmission) or “M” (manual transmission) on the bellcrank (see illustration),depending on what type of transmission is installed in the vehicle. 11 Slowly rotate the bellcrank until it reaches the throttle stop (wide open throttle) and

check to make sure the pointer aligns with the notch in the bellcrank (see illustration). 12 If necessary, adjust the position of the throttle stop using a spanner and turn the throttle stop screw until the bellcrank reaches the correct position. Lock the throttle stop screw in place.

4•8 Fuel and exhaust systems

3261 Jaguar XJ6

10.4 Remove circlip (arrowed) and separate cable from the

accelerator pedal by pulling the pin from the pedal assembly

10.2 Loosen the locknuts on the accelerator cable 10.3 Rotate the bellcrank and remove the cable end from the slot

10.9 Make sure the throttle closes completely and there is a slight amount of flex in the cable

10.10 Attach a strong wire (coat hanger)

to the master cylinder using a clamp and

align it with the notch on the bellcrank

13 Allow the bellcrank to return to the idle

position and test the adjustment once again until the correct adjustment has been attained.

11 Electronic Fuel Injection

(EFI) system -

general information

1 These models are equipped with an Electronic Fuel Injection (EFI) system. This fuel injection system is designed by Bosch but

licensed by Lucas and is called the Lucas LH Engine Management system. The EFI system is composed of three basic sub systems: fuel system, air induction system and electronic control system (see illustration).

Fuel system

2 An electric fuel pump is located on the chassis of the rear suspension (external) (1988 to 1990) or inside the fuel tank (1991 to 1994) The fuel pump supplies fuel under constant pressure to the fuel rail, which distributes fuel evenly to all injectors. From the fuel rail, fuel is injected into the intake ports, just above the intake valves, by fuel injectors. The amount of fuel supplied by the injectors is precisely controlled by an Electronic Control Unit (ECU). A pressure regulator controls system pressure in relation to intake manifold vacuum. A fuel filter between the fuel pump and the fuel rail filters fuel to protect the components of the system.

Air induction system

3 The air system consists of an air filter housing, a Mass Air Flow (MAF) sensor (airflow meter), Intake Air Temperature (IAT) sensor and a throttle body. The MAF sensor is an information gathering device for the ECU.

A heated element determines the temperature differential by measuring the current changes which in turn measures the mass (weight and volume) of air entering the engine. This information helps the ECU determine the amount of fuel to be injected by the injectors. The throttle plate inside the throttle body is controlled by the driver. As the throttle plate opens, the amount of air that can pass through the system increases, so the potentiometer opens further and the ECU signals the injectors to increase the amount of fuel delivered to the intake ports. Refer to Chapter 6 for additional information on the fuel injection system sensors, test procedures and renewal procedures.

Electronic control system

4 The Computer Control System controls the EFI and other systems by means of an Electronic Control Unit (ECU), which employs a microcomputer. The ECU receives signals from a number of information sensors which monitor such variables as intake air volume, intake air temperature, coolant temperature, engine rpm, acceleration/deceleration and exhaust oxygen content. These signals help the ECU determine the injection duration necessary for the optimum air/fuel ratio. Some

Fuel and exhaust systems 4•9

10.11 Rotate the bellcrank until it reaches wide open throttle and make sure the

pointer aligns with the A on the bellcrank.

Adjust if necessary

11.1 Fuel injection and emission control component locations for the 3.6 litre 1989 XJ6

3261 Jaguar XJ6

1 Fuel pressure regulator (under

fuel rail)

2 Idle Speed Control (ISC) motor 3 Fuel pressure damper

4 Bellcrank 5 Throttle body (below bellcrank) 6 Intake Air Temp. (IAT) sensor 7 Supplementary air valve

8 Mass Airflow (MAF) sensor 9 Throttle potentiometer (under

throttle body)

10 Fuel rail

11 Fuel injector 13 Ignition amplifier (below block

valve)

14 Distributor

of these sensors and their corresponding ECU-controlled relays are not contained within EFI components, but are located throughout the engine compartment. For further information regarding the ECU and its relationship to the engine electrical and ignition system, see Chapter 6.

12 Electronic Fuel Injection

(EFI) system - check

1 Check the earth wire connections for tightness. Check all wiring and electrical connectors that are related to the system. Loose electrical connectors and poor grounds can cause many problems that resemble more serious malfunctions. 2 Check to see that the battery is fully charged, as the control unit and sensors depend on an accurate supply voltage in order to properly meter the fuel. 3 Check the air filter element - a dirty or partially blocked filter will severely impede performance and economy (see Chapter 1). 4 If a blown fuse is found, renew it and see if it blows again. If it does, search for a shorted wire in the harness related to the system. 5 Check the air intake duct from the MAF sensor to the intake manifold for leaks, which will result in an excessively lean mixture. Also check the condition of the vacuum hoses connected to the intake manifold. 6 Remove the air intake duct from the throttle body and check for carbon and residue buildup. If it’s dirty, clean with aerosol carburettor cleaner (make sure the can says it’s safe for use with oxygen sensors and catalytic converters) and a toothbrush. 7 With the engine running, place a stethoscope against each injector, one at a time, and listen for a clicking sound, indicating operation (see illustration).

8 If there is a problem with an injector, purchase a special injector test light (noid light) and refit it into the injector electrical connector (see illustration). Start the engine and make sure that each injector connector flashes the noid light. This will test for the proper voltage signal to the injector. Caution:

If the engine will not start and the noid light indicates that each injector is receiving the proper signal, there is a good possibility that the injector(s) is stuck open and allowing fuel into the combustion chamber in excessive amounts. If the spark

plugs are fouled, detach the primary (low voltage) wires from the ignition coil, disable the fuel pump by removing the fuel pump relay (see Section 2), remove the spark plugs and crank the engine over. If fuel sprays from the spark plug holes, the engine is flooded and the fuel must be removed from the combustion chambers. 9 With the engine OFF and the fuel injector electrical connectors disconnected, measure the resistance of each injector (see illustration). Each injector should measure about 2.0 to 3.0 ohms. If not, the injector is probably faulty.

10 The remainder of the system checks should be left to a Jaguar service department or other qualified repair workshop, as there is a chance that the control unit may be damaged if not performed properly.

13 Electronic Fuel Injection

(EFI) system - component

check and renewal

Warning: Petrol is extremely flammable, so take extra precautions when you work on

any part of the fuel system. See the Warning in Section 2. Caution: If the stereo in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.

Throttle body

Check

1 Verify that the throttle linkage operates

smoothly. 2 Start the engine, detach each vacuum hose and, using your finger, check the vacuum at each port on the throttle body with the engine at idle and above idle. The vacuum available from the throttle body is ported. Raise the engine rpm and watch as vacuum increases. It may be necessary to use a vacuum gauge. Refer to Chapter 2B for additional information concerning vacuum checks.

Renewal

Warning: Wait until the engine is

completely cool before

beginning this procedure.

3 Detach the cable from the negative terminal of the battery (see the Caution at the beginning of this Section). 4 Drain the radiator (see Chapter 1).

4•10 Fuel and exhaust systems

12.9 Using an ohmmeter, measure the resistance across both terminals

of the injector

3261 Jaguar XJ6

12.7 Use a stethoscope or a screwdriver to determine if the injectors are working properly - they should make a steady

clicking sound that rises and falls with engine speed changes

12.8 Refit the “noid” light into the fuel injector electrical

connector and check to see that it blinks with the engine running

5 Remove the air cleaner (see Chapter 1) and

the air cleaner housing (see Section 9).

6 Remove the air intake duct. 7 Detach the electrical connector from the MAF sensor (see illustration). 8 Remove the clamp that retains the MAF

sensor to the air intake duct (see illustration) and lift the MAF sensor assembly from the engine compartment. 9 Detach the throttle cable from the bellcrank (see Section 10), then remove the bellcrank assembly from the throttle body (see

illustration). 10 Detach the kickdown cable from the

bellcrank and set the cable and brackets aside (see Chapter 7). 11 Clearly label, then detach, all vacuum and coolant hoses from the throttle body. 12 Disconnect the electrical connector from the throttle potentiometer. 13 Remove the four throttle body mounting bolts and detach the throttle body from the intake manifold. 14 Using a soft brush and carburettor cleaner, thoroughly clean the throttle body casting, then blow out all passages with compressed air.

Caution: Do not clean the throttle position sensor with any solvents or sprays. Just wipe it off with a clean, soft cloth.

15 Refitting of the throttle body is the reverse of removal. 16 Be sure to tighten the throttle body mounting bolts to the torque listed in this Chapter’s Specifications.

Adjustment

17 Remove the air intake duct to expose the

throttle body and butterfly valve. 18 Make sure the throttle body is clean and free of burrs, nicks or carbon build-up (see

illustration). 19 Measure the clearance between the

butterfly valve (throttle plate) and the wall of the throttle body (see illustration). It should be 0.05 mm (0.002 inch).

20 If the gap is incorrect, loosen the throttle stop locknut (see illustration) and turn the throttle stop screw until the correct clearance is attained. 21 Refit the air intake duct and surrounding components.

Idle Speed Control (ISC) motor

Note: The minimum idle speed is pre-set at the factory and should not require adjustment under normal operating conditions; however if

the throttle body has been replaced or you suspect the minimum idle speed has been tampered with (for example, if the idle speed screw was removed from the throttle body) have the vehicle checked by a dealer service department or a qualified automotive repair workshop.

Check

22 Start the engine and allow it to reach

normal operating temperature. Switch on the

Fuel and exhaust systems 4•11

13.9 Remove the bellcrank assembly bolts (arrowed) and separate it from the

throttle body

13.18 The area inside the throttle body

near the throttle plate suffers from sludge

build-up because the PCV hose vents

crankcase vapour into the intake duct

13.19 Measure clearance between the butterfly valve and the throttle body

3261 Jaguar XJ6

13.7 Push up on the clip and remove the harness connector from the MAF sensor

13.8 Remove the air intake duct clamp from the MAF sensor housing

13.20 Adjust the butterfly angle by

loosening the locknut on the throttle stop

and turning the adjustment bolt

headlights or heated rear window and confirm that the engine rpm decreases at first and then increases. This check monitors the ISC motor as it is signalled by the computer to increase idle speed due to additional amperage required from the charging system. As the headlights draw current from the charging system, the alternator will create resistance on the belt as it works to produce the additional energy. If the rpm does not increase, check the ISC motor. 23 Check for approximately 11.2 volts to the ISC stepper motor (see illustrations). Disconnect the ISC harness connector and working on the harness side, check for

11.2 volts with the ignition key ON (engine not running). Also, check the corresponding terminals for the correct voltage amounts. If the correct voltage does not exist, check the wiring harness. Refer to the wiring diagrams at the end of Chapter 12.

24 The ISC motor or stepper motor can be checked for correct operation but a special tool is required to activate the internal coils. Have the stepper motor checked by a dealer service department or other qualified repair workshop. 25 Reconnect the ISC motor electrical connector.

Renewal

26 Detach the cable from the negative

terminal of the battery (see Caution at the beginning of this Section).

27 Use a large open-end spanner and unscrew the ISC motor from the housing (see

illustration). 28 Refitting is the reverse of removal, but be

sure to use a new gasket.

Fuel rail and fuel injectors

Note: If there is a distinct knocking noise coming from the dash when the engine is idling, the fuel feed hose may have hardened

restricting fuel flow and causing abnormal sounds. Replace the fuel inlet (feed) hose with a new part from the dealer parts department.

Check

29 Refer to the fuel injection system checking

procedure (see Section 12).

Renewal

30 Relieve the fuel pressure (see Section 2). 31 Detach the cable from the negative

terminal of the battery (see Caution at the beginning of this Section).

32 Disconnect the fuel injector wiring connectors and set the injector wire harness aside. 33 Detach the vacuum sensing hose from the fuel pressure regulator. 34 Disconnect the fuel lines from the fuel pressure regulator and the fuel rail (see

illustration 3.6a) 35 Remove the fuel rail mounting bolts (see illustration).

4•12 Fuel and exhaust systems

3261 Jaguar XJ6

13.23a To check the ISC motor, turn the ignition key ON

(engine not running) and check for the proper voltage amounts

at the harness connector (1989 model shown)

13.23b Later models are equipped with a different shape ISC connector but the voltage values should be the same

as the early style

13.27 Use a large open end spanner to remove the ISC motor from the intake manifold

13.35 Remove the fuel rail mounting bolts (arrowed) . . .

Jaguar XJ6 1997 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual