Published by Service Communications, Jaguar Cars Limited
Publication Part No JJM 18 15 15/70, August 1996
Published by Service Communications, Jaguar Cars Limited
Publication Part No JJM 18 15 15/70, August 1996
Technical Guide
AJ-V8 Engine
and
5HP24 Transmission
Introduction
PrefaceAJ-V8/5HP24
This Technical Guide introduces the new AJ V8 engine and 5HP24 transmission installed in the XK8
Sports car. It is intended to give Jaguar Dealer workshop personnel an overview of their construction
and operation, and is for information purposes only. The contents of this Technical Guide must not be
used as a reference source for servicing procedures; all servicing procedures must be in accordance
with the appropriate Service Manual.
This Technical Guide will not be updated. While every effort is made to ensure accuracy, changes may
occur between going to press and the equipment being introduced to the market. Once the equipment
is in service, details of changes can be obtained from Service Bulletins and revisions to the Service
Manuals.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or
transmitted, in any form, electronic, mechanical, photocopying, recording or other means without prior
written permission from the Service Division of Jaguar Cars Limited.
Contents AJ-V8/5HP24
1
Subject Page
Glossary
Abbreviations 2
Introduction 3
Engine
Basic Engine 5
Engine Cooling 17
Engine Lubrication 20
Variable Valve Timing 24
Air Intake System 27
Fuel System 33
Ignition System 35
Crankcase Ventilation 35
EGR System 37
Engine Accessories 38
Accessory Drive 39
Engine Harness 41
Engine Covers 42
Engine Specifications 43
Engine Management
ECM 45
Electronic Throttle 53
Fuel Pump 58
Fuel Injection 58
Ignition 59
EVAP System 60
Variable Valve Timing 61
EGR System 61
Engine Starting 61
HO2S Heaters 62
Instrument Cluster 62
A/C Compressor Clutch 62
Windshield and Backlight Heaters 62
Radiator Cooling Fans 62
Diagnostics 63
Transmission
Introduction 65
Technical Data 66
Gearshifting 66
Mechanical Description 66
Electrical Description 67
Transmission Management
Transmission Management 68
Service Tools
New Tools 72
GlossaryAJ-V8/5HP24
2
The following abbreviations are used in this document:
Abbreviation Description
ABS anti-lock braking system
A/C air conditioning
A/CCM air conditioning control module
BPM body processor module
BHP brake horse power
˚C degree Celsius
CAN controller area network
CDI cubic inch displacement
DIN Deutsche Institut für Normung
dc direct current
DTC diagnostic trouble code
ECM engine control module
ECT engine coolant temperature
EGR exhaust gas recirculation
EMS engine management system
EVAP evaporative emission
˚F degree Fahrenheit
ft foot
HO2S heated oxygen sensor
in inch
JDS Jaguar diagnostic system
lb pound
lbf.ft pound force feet
kg kilogram
km/h kilometer per hour
kW kilowatt
m meter
MAFS mass air flow sensor
MIL malfunction indicator lamp
mph miles per hour
mm millimeter
ms millisecond
Nm Newton meter
NOx nitrous oxide
OBD on-board diagnostics
O2S oxygen sensor
PAS power assisted steering
PDU portable diagnostic unit
psi pounds per square inch
PTFE polytetrafluoroethane
rpm revolutions per minute
SAE Society of Automotive Engineers (USA)
SCP standard corporate protocol
TCM transmission control module
USA United States of America
V volt
VSV vacuum solenoid valve
Introduction AJ-V8/5HP24
3
The AJ-V8 4.0 litre, engine is the first of a new family of Jaguar engines. Designed to give excellent
performance, refinement, economy and low vibration levels it also conforms to the strictest emission
legislation. Weighing only 200 kilograms (441 lb), the engine is shorter by 12 inches (300 mm) than the
current AJ16 4.0 litre engine. Compression ratio is 10.75:1, with four valves per cylinder. The cylinder
heads, block and bedplate are all cast aluminum. Cylinders have electro-plated bores which reduce
piston friction, improve warm-up and oil retention. A variable valve timing system has been introduced
to give improved low and high-speed engine performance and excellent idle quality. The valve gear is
chain driven for durability. Low valve overlap improves engine idle speed and low residual fuel levels
which improves combustion and reduces hydrocarbon emissions. The inlet manifold is a one-piece,
composite moulding with integral fuel rails connecting to the eight side feed fuel injectors. Air flow into
the engine is via an electronic throttle assembly. Movement of the throttle is controlled by sensors in
the throttle assembly through the ECM. The engine has a low volume, high velocity, cooling system
which achieves a very fast warm-up with reduced and even metal temperatures in the combustion
chamber and increased bore temperatures.
The generator, A/C pump, and PAS pump are mounted to the cylinder block on rigid cradle supports.
Accessory drive is from a single, 7-ribbed vee belt. Hydraulic engine mounts minimise noise and
vibration.
A new engine management system adjusts fuel and ignition settings, monitors and controls exhaust
emissions and provides an on-board diagnostic capability.
The transmission is a new ZF 5-speed, automatic, electronically controlled unit.
The unit is oil filled for life so does not have an oil gauge (dipstick). Two driver selected modes are
available, sport or normal. The TCM is programmed with cruise, traction, gradient, warm-up and hot
mode features. It also provides an on-board diagnostic capability.
The engine and transmission meet OBDII USA environmental regulations.
Default limp home modes for both engine and transmission are provided.
Engine AJ-V8/5HP24
5
Basic Engine
The AJ-V8 is an all new 90° V8 liquid cooled engine that gives refined and effortless performance.
Constructed in aluminum alloy, the AJ-V8 introduces several innovative design features new to Jaguar
engines, the most notable of these being:
• a bedplate
• nikasil coated cylinder bores
• fracture split connecting rods
• variable valve timing
• aluminum alloy valve lifters
• electronic throttle control.
303-056
EngineAJ-V8/5HP24
6
ENGINE STRUCTURE
ENGINE DATA LOCATIONS
303-052
303-001
Cylinder Block
The cylinder block is an "enclosed V" design,
which provides an inherently rigid structure with
good vibration levels. Nikasil (a composition of
nickel and silicon) coated cylinder bores provide
good friction, heat transfer and piston noise
levels. A low volume coolant jacket improves
warm-up times and piston noise levels; the
longitudinal flow design of the jacket, with a
single cylinder head coolant transfer port in each
bank, improves rigidity and head gasket sealing.
The right hand cylinder bank is designated as "A"
bank, and the left hand as "B" bank. The cylinder
bores of each bank are numbered from 1 to 4,
starting from the front.
Engine data is marked at three locations on the
cylinder block. Component diameters are
represented by alphabetical and numerical codes;
keys to the codes are in the Service Manual.
1
2
3
4
1. Cylinder Head
2. Cylinder Block
3. Bed Plate
4. Structural Sump
Emissions Code
Serial Number
* Main Bearing Crankshaft
Diameters * Connecting
Rod Bearing Crankshaft
Diameters * Cylinder Bore
Diameters * Main Bearing
Bore Diameters *
Engine AJ-V8/5HP24
7
CYLINDER BLOCK, CRANKSHAFT AND BEDPLATE
303-011
EngineAJ-V8/5HP24
8
Bedplate
The bedplate is a structural casting bolted to the
bottom of the cylinder block to retain the
crankshaft. The use of a bedplate further
improves rigidity. Iron inserts, cast into the main
bearing supports of the bedplate, minimise main
bearing clearance changes due to heat
expansion.
Two hollow dowels align the bedplate with the
cylinder block.
Beads of sealant seal the joint between the
bedplate and the cylinder block.
Crankshaft
Six counter-balance weights ensure good
vibration levels from the four throw, five bearing
crankshaft. Manufactured in cast iron, the
crankshaft also has undercut and rolled fillets for
improved strength.
The main bearings are aluminum/tin split plain
bearings. An oil groove in the top half of each
bearing transfers oil into the crankshaft for
lubrication of the connecting rod bearings. A
lead/bronze thrust washer is installed each side of
the top half of the center main bearing.
The crankshaft rear oil seal (a lip seal similar to
that used on the AJ16 engine) is a press fit in the
bedplate to cylinder block interface.
SEALANT TRACK ON BEDPLATE
303-012
CRANKSHAFT REAR OIL SEAL
303-013
Engine AJ-V8/5HP24
9
Connecting Rods and Pistons
The connecting rods are manufactured in sinter
forged steel. The bearing caps are produced by
fracturing the opposing sides of the connecting rod at
the bearing horizontal center-line. As well as being
easier to manufacture, when re-assembled the
fractured surfaces interlock to form a strong
seamless joint. The cylinder position is etched on
adjoining sides of the joint to identify matching
connecting rods and bearing caps. The connecting
rod bearings are lead/bronze split plain bearings.
The pistons are of the open ended skirt design with
flat upper surfaces to reduce heat absorbtion. Three
piston rings, two compression and one oil control, are
installed on each piston. Each piston is installed on a
wrist pin located in a lead/bronze bushing in the
connecting rod.
Sump
The sump consists of an aluminum alloy structural
sump bolted to the bedplate, and a pressed steel oil
pan bolted to the structural sump. A windage tray
attached to the top of the structural sump isolates
the oil pan from the disturbed air produced by the
rotation of the crankshaft, to prevent oil aeration and
improve oil drainage. A rubber plug at the rear of the
structural sump seals the port that provides access to
the torque converter securing bolts. The engine oil
drain plug is located at the front right corner of the oil
pan.
A silicon rubber in-groove gasket seals the joint
between the oil pan and the structural sump; a bead
of sealant seals the joint between the structural
sump and the bedplate.
CONNECTING ROD AND PISTON
303-014
SEALANT TRACK ON STRUCTURAL SUMP
303-021
EngineAJ-V8/5HP24
10
Starter and Drive Plate
The engine starter motor is installed at the rear
right side of the engine, at the cylinder block to
bedplate split line (for further details of the
starter motor see Technical Guide, XK8
Introduction).
The starter drive plate is attached to the rear of
the crankshaft. A timing disc, for the engine
speed sensor, is spot welded to the front face of
the drive plate.
STRUCTURAL SUMP AND OIL PAN
STARTER MOTOR
303-062
Torque
Converter
Access
303-010
Engine AJ-V8/5HP24
11
Cylinder Heads
The cylinder heads are unique to each cylinder
bank. Deep seated bolts, to reduce distortion,
secure the cylinder heads to the cylinder block.
Two hollow dowels align each cylinder head with
the cylinder block.
The cylinder head gaskets consist of a silicon
beaded composite gasket with metal eyelets for
the cylinder bores, similar to that on the AJ16
engine.
Each cylinder head incorporates dual overhead
camshafts operating four valves per cylinder via
solid aluminum alloy valve lifters. Steel shims in
the top of the valve lifters enable adjustment of
valve clearances.
The lightweight valve gear provides good
economy and noise levels. Valve head diameters
are 31mm (1.220 in) for the exhaust and 35mm
(1.378 in) for the intake. All valves have 5mm
(0.197 in) diameter stems supported in sintered
metal seats and guide inserts. Collets, valve
collars and spring seats locate single valve
springs on both intake and exhaust valves. Valve
stem seals are integrated into the spring seats.
The camshafts are manufactured in chilled cast
iron. Five aluminum alloy caps retain each
camshaft. Location numbers, 0 to 4 for the intake
camshaft and 5 to 9 for the exhaust camshaft,
are marked on the outer faces of the caps. The
rear of B bank intake camshaft has a timing ring
for the camshaft position sensor. A flat,
machined near the front of each camshaft,
enables the camshafts to be locked during the
valve timing procedure.
CAMSHAFT POSITION SENSOR
TIMING RING
303-054
The 14 mm spark plugs, one per cylinder, locate
in recesses down the center-line of each cylinder
head.
An engine lifting eye is cast into the front of each
cylinder head (the rear lifting eyes, one on each
cylinder head, are bolt-on tools).
TIMING DISC
STARTER DRIVE PLATE
303-035
303-034
EngineAJ-V8/5HP24
12
Timing Gear
Single row primary and secondary chains drive
the camshafts of each cylinder bank. The primary
chains transmit the drive from two sprockets on
the crankshaft to variable valve timing units on
the intake camshafts. The secondary chains
transmit the drive from the variable valve timing
units to sprockets on the exhaust camshafts.
A BANK CYLINDER HEAD
303-047
Lifting
Eye
Intake Camshaft
Exhaust Camshaft
(Continued on Page 14)
Engine AJ-V8/5HP24
13
303-016 / 017
Primary Chain
Tensioner
Secondary Chain
Tensioner
Secondary
Chain
Variable Valve
Timing Unit
Primary Chain
TIMING GEAR
EngineAJ-V8/5HP24
14
A key locates the two drive sprockets on the
crankshaft. The crankshaft's torsional vibration
damper retains the sprockets in position.
The variable valve timing units and the exhaust
camshaft sprockets are non-interference, nonkeyed fits on their respective camshafts; the
drive being transmitted by the face to face
friction load produced by the valve timing
unit/sprocket securing bolt.
Each chain has an hydraulic tensioner operated
by engine oil. A jet of oil from the end of each
tensioner lubricates the chains. The primary chain
tensioners act on pivoting flexible tensioner
blades. The secondary chain tensioners act
directly on the chains. Guide rails are installed on
the drive side of the primary chains.
Timing Cover
The aluminum alloy timing cover accommodates
the crankshaft front oil seal (a PTFE lip seal) and
the two variable valve timing solenoids. Silicon
rubber in-groove gaskets seal the joint between
the timing cover and the front face of the engine.
TIMING COVER
Crankshaft
Front Oil
Seal
303-015
Timing Gear (Continued)
Variable Valve
Timing Solenoid
Engine AJ-V8/5HP24
15
Camshaft Covers
The camshaft covers are manufactured from vinyl
ester composite. The A bank camshaft cover
incorporates an outlet for the full load engine
breather. The B bank camshaft cover incorporates
the engine oil filler cap and an outlet for the part
load engine breather. Identical oil separators are
incorporated below the breather outlet in each
cover (see Crankcase Ventilation, page 35).
Silicon rubber in-groove gaskets seal the joints
between the camshaft covers and the cylinder
heads. Together with spacers and seals on the
camshaft cover fasteners, they also isolate the
covers from direct contact with the cylinder
heads, to reduce noise.
B BANK CAMSHAFT COVER
303-042
EngineAJ-V8/5HP24
16
Exhaust Manifold
The thin-wall cast iron manifolds are unique for
each cylinder bank. On engines with EGR, the A
bank manifold has a connection for the transfer
pipe.
Spacers on the securing bolts allow the
manifolds to expand and retract with changes of
temperature while maintaining the clamping
loads.
Heat shields are integrated into the exhaust
manifold gaskets.
EXHAUST MANIFOLD
303-023
Engine AJ-V8/5HP24
17
Engine Cooling
The cooling system is a low volume, high velocity
system with good warm-up and temperature
profile characteristics.
From the pump, the coolant flows into each bank
of the cylinder block. In each bank, 50% of the
coolant cools the cylinder bores and 50% is
diverted through a bypass gallery. At the rear of
the banks the two flows mix and enter the
cylinder heads. The coolant then flows forwards
to the outlet ports. When the thermostat is
closed, the coolant returns directly to the pump
through the bypass on the thermostat housing.
When the thermostat is open, the coolant returns
to the pump via the vehicle's radiator.
A coolant drain plug is installed on the rear left
side of the cylinder block. On vehicles with the
cold climate package, the cylinder block heater
replaces the drain plug.
Note: Coolant is drained from the right bank of
the cylinder block by removing the
coolant pipe behind the starter motor.
CYLINDER BLOCK DRAIN/HEATER
COOLING SYSTEM DIAGRAM
1. Electronic Throttle
2. EGR Valve
3. A/C Heater Return
4. Coolant Pump
5. Thermostat Housing
6. Vehicle Radiator (Reference)
7. A/C Heater Supply
8. Bleed Outlet
8
1
2
3
4
7
6
5
303-O63
303-028
EngineAJ-V8/5HP24
18
Coolant Pump
The coolant pump is installed between the two
cylinder banks, on the front face of the cylinder
block. The pumping element is a shrouded
composite impeller. Coolant escapes from seal
breather holes in the housing if the pump's
bearing seal fails.
An O-ring and an edge bonded rubber/aluminum
alloy gasket seal the pump to cylinder block
interface. The O-ring seals the inlet port from the
thermostat. The gasket seals the outlet ports into
the cylinder banks.
Thermostat Housing
The composite thermostat housing is installed
between the two cylinder banks, immediately
above the coolant pump. The thermostat controls
the flow of coolant through the radiator. It starts
to open at 80 to 84°C (176 to 183˚F) and is fully
open at 96°C (205˚F).
A duct in the cylinder block connects the
thermostat housing outlet to the pump inlet. A
stub pipe connects the duct to the air conditioning
heater matrix return line.
An in-groove gasket seals the joint between the
thermostat housing and the cylinder block.
In addition to containing the thermostat, the
composite thermostat housing incorporates
connections for the bleed, bypass and radiator
bottom hoses. The bleed outlet vents any air in
the system into the vehicle's coolant reservoir.
The cap of the thermostat housing is removable,
to allow air out of the system when filling from
empty.
CAUTION: Use the correct torque (marked on
the cap) when re-installing the
cap, or the cap/thermostat
housing could be damaged.
COOLANT PUMP
303-030
THERMOSTAT HOUSING
Coolant Hoses
Supply and return hoses for the air conditioning
heater matrix are installed between the cylinder
banks.
A connection at the rear of A bank provides the
coolant supply for the electronic throttle and the
EGR valve. The outlet from the EGR valve
connects to the return hose of the air conditioning
heater matrix.
By-pass
From
Radiator
A/C Heater
Return
Cap
Bleed
303-029