throttle body problems
 

i have a 01 XK8 the throttle body keeps accumulating a lot of oil residue. i've clean it out a couple of times and changed the air filter. still receivinga P1229 and P1000 error code when the car goes into 'fail safe mode" anyone with any suggestions?

Looking at the symptom, oil residue in the intake is caused by combustion blowby or clogged breathers or both, so check the compression first. If its low, you may not be able to stop the throttle body from getting dirty and throwing the codes. You can get some "Restore" and this will slow down the blowby. You can clean the TB and see if it lasts. Be sure to clean the part load and full load breathers, this can help too. If all this is clean, you are doing the best you can to slow the problem.

I have a 1997 XK-8 when I first bought it with 77K on it. It smoked a bit on start up. I changed the oil using Mobil 1 every year I have owned it. Now no smoke on start up. This car is mostly a weekend driver. I drive it less than 500 miles per year since I have way TOO many cars as it is. Just thought it might be a point of interest. I use FULL SYNTHETIC in all six of my cars three of which are four valve. Good Luck!!

You didn't mention if you had a K&N air filter. Sometimes the oil on their air filter will foul up the intake system.

These cars do better without oil based air filters.

the parts load and full load breathers, where are they located on the motor. and yes i did replace the filter with a K&N, but i was having the problem before then.

thanks to all

The P1229 is a throttle motor disconnect or motor failure. I would first check your plugs on the TB, Jaguar has a TSB 303-58 that references a problem that is related to TB a P0121 code but I seen other codes caused by the mismatch in the plugs. Remove and clean them and see what takes place.

Links jaguar throttle body plug & http://www.jagrepair.com/images/TSB/XK8/303-58.pdf

As for the blowby do you know if you have a Nikasil block? If so this might help to understand the situation Jaguar Nikasil & Sulfur I would not be alarmed with the blowby just yet first get rid of the cause of the failsafe. I would also suggest as mentioned cleaning the breather stub. As for K&N filter not to worry it has not caused a problem in either of my vehicles unless it was over oiled and right now you should not be concerned.

Thanks...that sounds very helpful. one question where and how many are these breather stubs and how do you clean them out?

thanks again.

The part load breather is located on the left valve cover and connected to the throttle body. It can get clogged up and cause all sorts of little issues. CAREFULLY remove the plastic connector at the valve cover as it will be much more brittle than it was 10 years ago. Use a small drill bit, 3/32nds if I remember correctly, to clean the hard crud closing up the little opening. Use a pair of vice grips, not a drill motor. The actual orifice is 3/4" down inside the housing.

The full load breather is the tube connecting the right valve cover to the the air filter to throttle body duct.

This is the TSB 600-03

i think i clean out the breathers...thanks guys. the car idles fine after i cleaned the throttle body bowl. so i don't think its a wire connection. so how do i check the compression for the blowby?

thanks for all the help!!!!

read the attachment Gus. where can i find the molybdenum disulfide (moly)?

thanks everyone!!!

Thanks guys for all the help!!! She runs great now after i completed all of you guys suggestions. I owe everyone dinner if you're ever in Dallas/FtWorth area.
Special thanks to you Gus!!!
Appreciate it!

Gus is WAAAY to far away, I got dibs on his wings. Hooters ok?