redbullgotwings

Okay so i just bought an Audi A6 Quattro 2.8l and it has some issues.
it has 87k on it and its a 99. its been taken care of timing belt was done at 80k oil changed every 3k and paperwork to prove it.
PO was dirving it and all of a sudden it started sputtering and bucking, he was 10 miles from home so he just drove it and parked it and then i bought.
the car starts and rev's to about 2k rpm and then bogs down.

UPDATE: so i took my spark plugs out to test compression and this is what i found... they were covered in oil? it was on the wrench too so i think its a valve cover gasket leak. its on both cylinders 1 and 4 i havent checked any others. what do you guys think



here is the most recent scan


Address 01: Engine Labels: 078-907-551-AHA.lbl
Control Module Part Number: 4D0 907 551 AH
Component and/or Version: 2.8L V6/5V MOTR AT D04
Software Coding: 06252
Work Shop Code: WSC 02325
VCID: 6CD3C083361B
3 Faults Found:

17953 - Throttle Valve Controller: Malfunction
P1545 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16688 - Cylinder 4: Misfire Detected
P0304 - 35-00 - -

Readiness: 0110 1101


so i think i need a coil pack and maybe a throttle body?
i dont know about the throttle body though i thought i would just need to do a TBA but when i went to do it, it said error. maybe thats cuz of the misfire.

anyone's input would be great. thanks.

oh and pics

Just Me

hard to say. That much oil in the combustion chamber seems either unlikely, or downright catastrophic. But might it have been in the plug holes (it drips down there all the time)?

have you pulled codes? There MUST be codes. That's the place to start.

G

4Driver4

Valve cover gaskets.

Huskerbob

And as long as you're there do the cam seals and tensioner seals. You'll be back if you don't. Make sure you follow the instructions for using RTV on the corners of the VCGs.

Teutonix

Oil on the plug, as stated, is a minimal issue (VCGs). I probably would wait to fix that one until you get the running issue sorted..

For your driveability issue and misfire problems, I'd bet the farm that it's a coilpack failure. I've seen the same issue before with the same symptoms. To test, move cyl 4 coilpack and see if the misfire follows. At this point, I'd probably just swap all the coilpacks... It's not terribly expensive.

The throttle control error is an intermittent implausible signal. You may try getting the car up to temperature and then use the high-tech (vag com) or low-tech (let it sit with engine off, ignition on) methods to adapt the throttle body. Sometimes the engine temp can make the difference.

This should be a pretty simple/cheap fix to get you on the road.

4Driver4

Except that the leak *is* the root cause of the misfire.


The odds are against you. You'd probably end up homeless. Coil pack failures are extremely rare on the 2.8. Further, it nearly impossible to swap coil packs are they are a single unit remotely mounted.


This only works for drive by wire cars. 99 is drive by cable. VAG-COM is needed.

Just Me

I've also seen "implasible signal" when the throttle body butterfly gets a ridge of dirt and carbon build up, and thus is blocked. I cleaned it out with carb cleaner, ran it through its range a few times (aka italian tune up) and all was well.

G

Just Me

99. aha. disregard my comment below - that was drive by wire.

G

Teutonix

Ugh... Thanks for the correction. I need to stop coming to this forum. It's been too long since I've touched cars of this era, and I forget what the technology of the day was.

4Driver4

Could always buy a C5 to help refresh your memory! ;-)