Jaguar XKR 2008 Cleaning Your Jaguar Cleaning Your Jaguar

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TITLE Cleaning the Jaguar XK8/XKR Throttle Body, MAFS, and Part-Load Breather

Dan Pechonis

Project Time Required: Approx. 1 Hour

Last Update: April 11, 2008 – Version 2.5

Author Parts Store Items Needed Tools Needed Skill Level

Basic

Intermediate

Professional

[e-mail]

Forum name: MrTexasDan

• Throttle Body Cleaner – *NOT*
carburetor cleaner. (Recommend CRC
brand)

• Electrical contact cleaner – Must dry
residue-free. (Recommend CRC brand)

•

Lint-free cloth

• Flat blade screwdriver

• 8mm and 10mm nut

drivers or sockets and
ratchet

• 3/32” (2.5mm) drill bit

• Vise Grips

• Pliers

• Phillips-head screwdriver

• 10mm wrench (for battery

terminal)

Author Comments

I own a 2000 XKR. At 82k miles, I was experiencing hard starting and hesitation/rough running when the engine was cold. Also, at any engine
temperature when I stepped on the gas from a standing stop, the response was quite “jerky” and the car lurched.

After some online research, I set out to do a little maintenance that probably has never been done on my car (I bought it at 67k miles). Namely, I
cleaned the Throttle Body, Mass-Air Flow Sensor (MAFS), and Part-Load Breather Tube orifice.

After performing these steps (in less than an hour!), the hard starting and hesitation were gone, the throttle response was smooth, and I got
noticeably more power. I have added this procedure to my maintenance schedule for every 10k miles.

Many thanks go to Jeff Cline, SidVaga, and Bloodworm for their help and posts on this subject. If I ripped off any of your words, it is only because I
couldn’t have said it better. Any inaccuracies or omissions are my responsibility alone and not that of these fine people.

Corrections or suggestions for improvement would be sincerely appreciated.

This document may be freely distributed in its complete and unaltered state, with the author’s name and email addresses included.

Procedures

• Clean connectors, hoses, and other parts as you go. This is good practice in general. Clean parts are happy parts.

• Under-hood plastic is notorious for being brittle and breaks quite easily. Handle with care.

• Care should always be taken to protect the paint while you lean over the fender. Wash dirt off the bodywork *first*, put covers on both

fenders, remove belt buckles, and watch for rivets in jeans or metal zippers, or other potential hazardous bits.

Instructions

STEP 1

tangs securing the tube so that it then can be pulled out from the duct. Rotate the breather tube out of the way.

Disconnect the full-load breather tube from the big air intake duct by squeezing as shown. This releases the

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Note: Do this very carefully, as it is quite easy to break old brittle plastic here … a new one cost me $17 at Jaguar. Also
check that the full-load breather tube has no cracks or leaks. Even small air leaks here will throw off the air-fuel mixture.

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STEP 2

Loosen the hose clamp securing the large air intake duct to the air cleaner box.

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STEP 3

Remove the 2 bolts securing the air intake duct to the throttle body. The upper bolt is 10mm and the lower bolt

is 8mm (why – I don’t know. And for that matter, why they are both on the same side while there is no bolt on the other
side is a big automotive engineering mystery).

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STEP 4

Remove the intake air duct …

… To reveal this very dirty throttle body.

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STEP 5

Have someone hold down the throttle pedal to make it easier to open and clean the throttle body valve. If you

have no friends to do this, use something like what I rigged up in the picture. Notice the bunched-up rag to protect the
leather.

STEP 6

Here’s where we get to cleaning. Spray throttle body cleaner on a lint-free rag. Reach in and open the throttle
valve, and wipe down the throttle bore as far in as you can get with your fingers. On my car, the gunk was so thick that it
took many wipes to get clean. Also clean the throttle valve itself, especially on the edges.

Note: Use only your fingers and the rag, and not any hard sharp implements. It is easy to damage the coatings on the
throttle bore and valve.

Warning: DO NOT spray cleaner directly into the throttle bore. This would cause flammable cleaner to pool up at the
bottom of the throttle body (and supercharger on XKR). I’m guessing an explosion in here would be bad.

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