hey everyone,

this post may be much of a repeat to 2K S4, but for the rest of you itwill be new. i found myself a 2000 S4 with 105k+ miles. the car is in great shape inside and out and drives incredibly smooth. unfortunately the car does not feel like it has the 250hp and 258ft/lbs of torque, it actually feels slower than a 1995 Civic DX.I ran a VAG diagnostic on it and discovered these faults for the engine control module:


Address 01: Engine Labels: 078-907-551-AZA.LBL
Part No: 8D0 907 551 A
Component: 2.7l V6/5VT G 0003
Coding: 06611
Shop #: WSC 06325

5 Faults Found:
17866 - Exhaust Gas Temp Sensor 2 (G236): Short to Ground
P1458 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16690 - Cylinder 6: Misfire Detected
P0306 - 35-00 - -
16686 - Cylinder 2: Misfire Detected
P0302 - 35-00 - -
16689 - Cylinder 5: Misfire Detected
P0305 - 35-00 - -
Readiness: 0000 0000

could any of these problems have caused the car to go into LIMP mode? how do you know when you are actually in LIMP mode? would VAG COM have told me what modein the printout?? if i erase all the DTC's will the engine return to normal running mode temporarily? the engine sounds silky smooth but feels like it has the power of an engine thats half the displacement with 3 psi of boost. there is no smoke and no leaks, and the owner swears he has only put synthetic oilin the engine.

my ideas of what could be wrong:
1. at one point in time the tbb/dv rippedand caused limp mode but the ecu was never reset.
2. 3 coil packs have gone bad
3. 1 of the ignition coils has gone bad
4. spark plugs?
5. the exhaust gastemp sensor needs to be replaced ($300 -_- )
6. hmm, i dunno

if everything checks out, and i can figure out/locate the parts needed for the repair i may buy the car within the next couple days. let me know what you guys think, i would really appreciate it

 

i apologize for my lack of patience, but i was hoping to get a couple responses before i see the car again in the next two hours. thanks for your time everyone

 

zzzzzz....

 

bad egt causes limp

 

Needs a new EGT sensor, it can cause limp mode & misfires. However, it's usually only on one bank. So you might also have a failing coil pack, plug, leaking injector, or a bad coolant temp, or MAF.

However, you really can't do much until you change out the EGT, there like $300 & kind of a PITA to get at.

You might also want to disconnect the MAF & see if runs a little better unhooked, if so, it also needs a MAF. You need to test the CTS with a Ohm Meter, don't know the value off the top of my head.

Big picture, this is a minor, normal problem. I would also guess on a boost leak form the TBB, or DV's, as most used ones do.

 

thank you for the responses. this pretty much leaves me buying the car as is, and then installing a new EGT #2 and replacing coil packs and spark plugs. unfortunately i do not know what else is wrong with the car and in reality wouldn't be able to find out anyway until the EGT sensor is replaced. oh well.... guess i have to go out on a limb on this one

 

100% replace the EGT, I bet most of the misfires, if not all, will be gone. Don't really plan on the coil packs, yet. It's an S4, this will not be an uncommon thing that pops up. Things just fail, & will cause havoc on the car, till they are fixed. The codes thrown are not always, the problem, but the symptom of the problem.

 

ok hereare, most likely,my last questions before i go ahead and make my purchase:

if the car is in limp mode, obviously producing low boost, would there still be sufficient "spool-up" to notice any malfunction/noisefrom the turbos, signalling that they are on their way out?

what clutch would you recommend i replace the factory 105k+ mile one with? is the RS4 clutch sufficient even if i were to upgrade to K04's at a later date? do i need something stronger?

 

I've heard the RS4 clutch does a good job, you should be safe.

 

You can really only tell if the turbo's are really gone, in limp mode, but a blown turbo is kind of hard to hide.

RS4 is fine even for a modded engine.