I've cleaned the wheel speed sensors, cleaned the contacts, changed the fuel filter, changes the spark plug, changed the air filter, cleaned the MAF sensor and this is still with me.

When changing the spark plugs I noticed some oil leakage above the on a couple of the plugs.

The car will also lurch at time, usually only when cold at slow speed (i.e. nothing happens when you hit the gas, then it jumps).

Any potential culprits other than failing chain tensioners or transmission?

 

It could be the ABS module
https://www.jaguarforums.com/forum/x...-repair-62539/

 

I also opened the module and checked the soldering which was fine.

 

A couple more suspects in ABS / Trac land:

- WeaK battery. Have you tested it?

- Failed sensor. There is a pretty reliable resistance check for this.

Maybe you've checked these items off already ...

 

Not checked those two, links in the fixit sticky?

 

Haven't looked in a while but pretty sure the resistance check stuff is there. Let us know if it doesn't pop up.

Do you have a digital voltmeter? If so, a really good battery indicator is "rest voltage". Measure it after an overnight, before starting the car.

 

I would strongly recommend you carry out the resistance checks at the ABS module connector. I had the same problem with the ABS and Trac Not Avail warning coming up as soon as the self check had completed. The resistance test revealed the rear left sensor had failed. Easy fix after that.
Andy.

 

I had my alternator replaced with a cheapo aftermarket one and it doesn't supply enough voltage at all time. When I start the car it ALWAYS says traction control not available for a second then comes back. Another symptom is at night, with lights on, while car is idling the the instrument cluster shows a slight flicker like the voltage is too low.

I would verify you are putting out enough amps at your alternator; I don't know how to test for that but any place that sells batteries should have the tester.

 

Don't discount other components in the ABS module, i've seen capacitors oozing, and there have been more than one module go off for rebuilding that didn't appear to have the soldering break, but came back fixed and resolved the error.

 

Get always the same problem after the batterie has flattened a few times. Going to go for a new one in an hour.

 

Does the light go off when you start driving? If, so it could be the wiring harnesses that are zip tied to the upper control arms. Someone has mentioned this before but I was pretty skeptical as my car was giving me intermittent DSC system faults, the ABS light and apparently a related issue with clunky brake pedal feedback. After a lot of cleaning of the sensors, connectors and inspecting the modules I looked at the wiring harnesses as a last resort prior to repacing components. It worked, as I was finally able to cure it by simply removing the zip ties, adding slack and re-tying them.

 

Good tip above. While you're checking your wiring harnesses, look for splits and cracks in both of the rear harness rubber boots. If you peel these split areas back, you can see the two wires inside the harness sheath. Never a good thing when these wires are exposed to the elements....

Back in mid-March I thoroughly cleaned both of my wife's XK8's split and cracked rear harness rubber boots with a rag soaked in dishwashing detergent. I let the area dry completely, then filled the splits and cracks with a flexible clear neutral-cure RTV silicone caulk that I purchased from Lowe's for about six bucks. I built up a round ball of silicone caulk at each rear boot. I did this with multiple applications of the silicone caulk approximately ten minutes apart. I then let the silicone caulk cure overnight before driving the car again....

No issues or warning messages since I did this repair. I checked the rear boots yesterday when I had both rear wheels off the car, and my silicone caulk "*****" appear to be holding up nicely. I expect them to gradually wear away as the elements hammer them. But I have plenty of silicone caulk left over in the tube so if this becomes a semi-annual or annual task, it is very easy to do. I'll just do it as part of my 6,000-mile tire rotation....

 

Testing Results

All wheel speed sensor resistances 1.12 +/- 0.02 kOhm
Battery overnight resting voltage 12.47 V

Extra info

Sometimes the ABS signal comes on when just turning on electrical power and not the engine.

Sometimes it remains, sometimes it goes away after starting the engine. (mostly the former).

Sometimes it doesn't happen at all.

 

Try carefully resoldering the module connector pins with a high quality flux core solder anyway. Some solder breaks literally need a microscope to detect visually.

 

I will do a rear wheel speed sensor cleaning first as I haven't done that.

 

Couldn't hurt, but a dirty sensor can't create a fault before the car starts moving.

Sometimes just the act of re-seating connectors as part of the cleaning can clear a fault though. Couldn't hurt.

 

This conundrum is ongoing in this thread - issue still there, probably ABS box :| https://www.jaguarforums.com/forum/x...x-51172/page4/

 

Have a similar issue. When slowing down for a stop sign or traffic signal, then resuming gas I get a jump, not a smooth take off. Only if not a complete stop.
I'm always worrying about tensioners even though my engine is supposed to be the later tensioner model. My engine is a late 2002 build. I think August or September.

 

If memory serves, August or September is when the engine changes were made (you are using the engine number date not the car build sticker, right?).

If it were my car, and I was concerned, I would pull a cover and look. Not a difficult job and then you know for sure.

 

I've been thinking about that.
I know when I checked with my dealer, they looked up my vin and said the engine build dat was after the change but only by weeks. You just never know! And I've got right at 100k on it so its that scary time!