Hello All,

I purchased a cert used 2004 S4 Avant (auto) a few months ago...It had a leaking rear main seal that was replaced by my local dealership. After the rear main seal proceedure, the car seemed to shift differently. Much 'harsher' shifting overall, but most noticable when I was aggressive with the gas pedal. About 75% of the time when'flooring' the gas pedal, I would hear a loud 'thunk', accompanied by a 'lurch' in the power (so my body would rock forward in the car)...this would last a fraction of a second, and then the car would feel 'normal'. I never noticed this before I had the rear main service, and it's 1) annoying and 2) makes me nervous that I'm going to floor it one day and see my transmission in my rear veiw mirror.

I took it to the dealer, who test drove and looked for error codes, but found nothing. So a few question: Any thoughts as to what this might be? Low fluid? Somehow mis assembled after the rear main proceedure? Somehow damaged during the proceedure?

I've had some good luck with running Redline transmission products in other cars...any thoughts that a different fluid may help? Anyone running Redline tranny fluid in a B6 S4 and can recommend something?

Thanks for the help! Battman

 

I dont knwo anything about the newer S4's, are you sure it dosent have any mods? Because i have a few friends with 2001 s4's, they're chipped and they have hard shifting like that becaue of the power that going to the tranny. I doubt your having that problem but i would go to the dealership and have them fix your tranny under warranty. If they say they didnt find anything have them test drive it, or you can test drive one they have on the lot and see if its the same as yours. I really cant help you more than this. I have noticed this places (audiforums) isnt to active. Try these too site, they are the most popular and they have constant activty through out the entire day and night, i knwo they can help you at either of these places www.audizine.com or www.audiworld.com good luck and let me knwo if you find the problem

 

It sounds like the trans fluid is a little low. Filling the TIP is a process & not just putting fluid in the hole.

Yes, Redline works fine, at least in my 00 Tip. Audi uses "Lifetime" fluid, so they do not like to change it. But I WOULD make it part of my maintiance plan.
Mine was nasty! I wish I took pics of it.

Take it back, & let them know, tell them, you think the fluid is low, and you want them to test it. The car needs to be up to temp, & running, with the trans engaged to check the fluid.

 

Thanks for the replies guys. I have complained to the dealership...the claim to have done a test drive and checked for error codes, and they said they found nothing.

Good question on the chip. The cert used car had an aftermarket exhaust, aftermarket stereo, cold air intake and built in K40 radar. The dealership where I purchased the car had returned the stereo and exhaust back to stock, but I still have the intake and K40 (probably because it was cheaper to leave them). However, I have no idea if I have a chip? Here's a dumb nubie question: where's the CPU to check? And were thinking an engine trip or transmission chip or both? I guess this is a possibility. However, the fact remains that the shifting got a lot worse after the rear main seal proceedure. I wonder if the previous owner ran redline or different fluid that helped?

I'm all about changing my own fluids (although I was foolishly assuming I was fully covered by Audi service for awhile)...2K S4: so you pull the trans fill plug while the car is running and car is in drive to check the level? It's a weird fill hole that's also a drain right? Do I need any special tools for this?

Thanks everyone!

 

Really sounds like you have a REALLY, REALLY bad shop! I would find another one, no matter how far it is, and have them work on the car.

Yes, it is a combo, drain/fill. If you do it with the car off, fluid will come out, & you will be low. So....
Engine up to temp
All 4 wheels off the ground
Car running & in gear
Open Drain/fill plug
Use any pump to well, pump fluid in there until it comes out, then put back in the plug.

Audi uses "Lifetime" fluid, so the dealer, or other shop don't like to change it. I'm very happy that I did mine!

 

VAG uses "lifetime" fills on all of its auto trannys and cooling systems. This also eliminates the rebuilding of automatic trannys at the dealers as they are not supposed to open the cases. The best way to change the fluid is to use a fluid exchanging machine, like BG that will clean the orifices, condition the clutches, and refill with new fluid. Try to get a BG trans. service. The ECU is under the wiper cowl, and easy to get at. Pull the plactic off and remove the 7 or so screws to pop off the cover, dont forget the one in back. If it has a chip it will likely have a sticker sealing the case closed( Found this out when i pulled mine out, thought it was OCT but it has 2 MTM seals on it). Not sure where the Trans Controller is though, maybe someone else can help to check for a tip chip.