In another post related to stalling someone mentioned the "much dreaded" thrust bearing failure as a problem related to engine stalling. What exactly are the symptoms related to impending thrust bearing failure, and what is the outcome of thrust bearing failure? This was brought up when I mentioned that my '88S4 stalls constantly at low-load/low-RPM. The engine always restarts and runs fine. I have had this symptom for at least two years - the engine has stalled hundreds of times and always restarts. Impending thrust bearing failure? Define impending based on that!

 

If I remember correctly ( and I could be wrong ) I do NOT think your car will "run fine" other than stalling if you have thrust bearing failure.

 

Sounds more like MAF or LH ECU problems.

How many miles on the car ?
Does the car idle at the correct speed ?

 

with thrust bearing failure the car will not be driveable....

think of it as a little mouse inside with a HUGE jack hammer .......

Sorry..I finally got me sense of humor back...


Dave

 

Stated in the other thread. It's quite logical. The car may start well and run thousands of miles with no issues. However, when the engine warms up, the engine may bog down, and require some gas pedal to allow it to idle smoothly. At some point it may stall. Restarting will result in poor idle or no idle. Till engine cools. After some time of this condition the engine will no longer tunr over. I have a TBF engine I like to show people and it is not pretty. lots of machining going on in there. Block unusable, cradle unusable, crank unusable, bearings worn all the way through (there is not much to begin with).

 

So Dave .... latest news?

 

got an SUV as a daily with a warranty.......

not more porsches for me for a while.

I sold the car. WAY to large a project for me.

 

Sorry to hear that man. Next time ... keep the targa too

 

I can see TBF starting out innocently enough by shutting down engine when on idle and engine is hot. On first times restarting right away wouldn't be so surprising as start motor could push crank just barely and free it. Problem should get worse pretty rapidly though.

 

Dave's car will be ressurected by some cool guys on the east coast.....!

 

If you suspect TBF, why not do the check. It takes less than an hour.
Go to my web site for the procedure.

http://members.rennlist.com/captearlg/

 

TBF can also be preceded by overheating or running hot issues. How's your temp?

 

Thanks for the posts guys. I do not suspect impending TB failure in my case - I don't have overheating issues, and the engine always resarts and runs fine. I'm not kidding when I say I've had this problem for more than two years and the engine has stalled hundreds of times. It always restarts and runs fine. It's even happened when running along on the highway with low-throttle / low-load / low RPM. Every time I can just shift into neutral, let the engine finish stalling, and restart right away.

I would have had it repaired long ago but it's a "ghostly" problem in that there is nothing to find with diagnosis. My mechanic in Toronto is a 928 specialist and is very good. Even he is reluctant to suggest swapping out expensive electronics just to "see if it works". He also points out that if the brain were on its way out it would have died long ago - electronics don't go through the "throes of death" for two years worth of daily driving (and also, a new computer would be a $1500 investment for me in an electronic part that's been sitting on a shelf somewhere for the past 10 or 15 years - not a promising investment).

 

I sincerely hope no-one makes big mistake and buys new LH-Jetronic box or MAF from anywhere when there is much cheaper and better alternatives:

http://www.jdsporsche.com
http://www.electronikrepair.com

 

Bookmark the links Erkka provided - in addition to good info on LH, EZK, and MAF modules, a LH rebuild with 'modern' advanced components is 1/3 to 1/2 of the above figure.
BTW, would your 928 specialist happen to be Dave?