Hey All;

I really could use some help.. I recently purchased a 1998 S4 1.8T Quattro with 102K for my son. It has been in the shop since I brought it home. So far I fixed the heat, replaced the alternator, idler pulleys, flush/filter in the trans, flush cooling system, oil change to synthetic, this was all about $1850 at the Audi dealer. I'm making progress ;-) BTW - looks like the timing belt has been done recently.

It still have one large nagging issue with the trans. It "revs" between shifts (automatic / tiptronic) 500-1000rpm. The dealer did find that the trans has the wrong fluid in it - probably someone else changed this while trying to fix this same problem at a hack shop (or at home). The trans shifts differently all of the time - sometimes better, sometimes worse. Once in really cold weather (right after starting) it shifted like normal. In addition to this - the cruise control is not working properly.

When I purchased the car I got carfax, and noticed there was an entry somewhere in it's life for "electrical system serviced". I am wondering now if the problem might be electronic related? TCM maybe? The audi dealer did unplug it - but resetting it did not change anything. I see very few posts in this forum for mechanical transmission problems, and the dealer says they are very rare. Is it possible that the shifting problem is related to the TCM, and that the cruise control problem is related?

Any help greatly appreciated.

Mike D.

 

Looks like it might be a bad selenoid or time for a rebuild.

 

Where is the selenoid located? Is this something that can be changed without dropping the tranny?

 

i believe theres 5 selenoids for of course the 5 gears you have so from what ive been told there internal and can start to go bad after around 100k thats what happened to me and it only gets worse. Take it to a couple of transmission shops and make sure they work on audi's alot of transmission places will def say they work on them and have been in the business for years but dont go for there bs cause half the tranny shops i went to didnt even have the tools to take mine out.

 

That makes some sense... like the shift between 4-5 is perfect every time. The shift between 1-2-3-4 is where I see the most rev / slip. Is that what your's was doing? What did it cost you for the rebuild?

 

yeah it would slip real bad in 3-4 and eventually driving for a while it would go into fail safe mode and then stay in 5th until i turned it off and on (reset) for a full rebuild i got mine done for 3800. Depending on who you take it to expect between 3k up to 5k.

 

Keep in mind the more you drive the car without knowing if the tranny is bad the worse its going to get id suggest getting out to a couple of places asap. The more those gears slip the more problems your going to run into (pumps,valves,etc) they all could be damaged.

 

Rebuilds on the transmission are not inexpensive. It could be a bad solenoid or perhaps the Transmission control module. Do you get such 500-1000 revs when driving gently?

 

It seems better when driving gently, however is still does not feel normal (compared to other cars). The last couple of times out it seems slight better once it is warm - but is always revs some. It revs when shifting via tip also - seems to make no difference. I've experimented with several shift patterns and rpms looking for that magic combination - but it pretty much doesn't matter. Revs in all of them. I think that second is also slipping as well - so I am starting to think its the tranny and not the TCM.

Does anyone have experience with a failing TCM ? What are the sypmtoms? I'm going to start making some calls this week.

Mike D.