Oh I am soooo glad the transmission trivia is solved in my 1995 Audi A6. Okay I bought this car 5 years ago, it had 51,000 miles on it when I bought it, it is a beautiful pearl white, with the ecru color leather. I bought a warranty on it (it was not CPO) and at 63,000 miles the trans started to rattle when the car was started until it warmed up. Well the Audi dealer used my warranty and replaced the whole transmission, well about 3 months ago the car started to do the same thing at 116,000 miles. It would rattle like rocks in a aluminum can until the car warmed up. once it warmed up the car was quiet and it drove great. All my local mechanic knew is that it was coming from the trans, so I hit the Audiworld forum and researched all types of transmission problems, I looked at Paul W, A8 audiworld pages, even though this was a 4 speed and those are 5 speeds, the A8's were having this bad rattle sucking noise. I found out this was the pump sucking air, and that a tranny fluid & filter change should solve this, I then had the tranny fluid changed, no luck, I e-mailed Paul W to pick his brain, I then had the fluid and filter changed again, NO LUCK !!!!! I then contacted ZF transmissions and talked to the Audi tech there Teri (this guy is VERY helpful and knows these Audi transmissions) I then decided to take the car to Paul W's buddy and mechanic Vladimir in Forest Park, IL. Anyone that Paul trust and use has gotta be good. I gave him ZF transmissions contact info for Teri and they talked, I told him about the 2 times the fluid & filter was changed, he got the diagrham for my transmission, and as a lucky guess, he thought about trying to check the breather hose, he cleaned the hose by shooting compressed air through the hose. It worked !!! after more research it was determined that the breather hose was clogged and when the car was cold it was creating a vaccum until the car warmed up and the torque convertor filled up. Now, the car is quiet as a mouse when it starts up, it now has 121,000 miles on it and runnig great, and although I have a super sharp 2000 A6 4.2, I still love my 95 A6 and it is my daily commuter mostly, no it is not super fast (it's not fast at all) but it a very good highway car and it still looks great after 10 years, paint & finish. Paul W, you rock !!!!!

 

in 2000 with 27,000 miles. I now have 150,000 and it's never been fixed. I may have to do some more searching. For the first 3 winters, each time it would get below about 40 degrees f, the noise would come and I'd take it in. Nothing would become of it, and as the weather warmed up I would forget about it until the following Novemeber. I even had the service manager and the head tech (who spoke german and broken english at best) - after they kept the for several days to get early morning cold starts - hear nothing until I started the car to leave and then dragged them both out. Both agreed there was a problem and that the transmission needed replacement and to call to schedule. When I called the following morning, the serv mgr memory of even listening to the car had vanished, and as I had nothing on my service order mentioning it he was unable to help me. And no, AoA could not possibly have cared less. Certainly haven't been back, but have suffered no ill-effects for the past 123,000 miles, either.
Then again, read my recent post about draining the fluid as I try to cancel out all of the good luck I've had with the car to date in one fell swoop.

 

Hi Jonathan
Thanks for the info. My 95A6Q is doing the same cold rattle. Can you show us where is the breather tube and maybe a picture will help???
Thanks in advance
Denny

 

Good info! Second the request for picture of "breather hose"

 

Oh man, is that ever GOOD TIMING! Thank you!!! someone know where this hose is??

 

have resolved the problem. The fluid is so expensive from the dealer. The filter material did look a little different and I noticed the aftermarket one was stamped with 33% while the dealer filter was marked 30%. Don't know if that is meaninful?

 

I had that problem 2 years ago, changed the filter and had the tranny flushed and it hasnt been back since.

Do not go by what the dealership or owner's manual says about never having to change the fluid.

 

this car has truely been a near-beater for me racking up milage and serving as the truckster on weekends. The car had had minimal maintenance and has served me very well for 150,000 miles.

That is until my idiotic gaff outlined in the issue several posts down...

As soon as the weather melts what just fell, I'll be dropping the pan and replacing the filter.

 

The manual says change the ATF every 4 yrs/45K miles, not lifetime for the C4.

 

Sorry about reopening this old thread but I had some unexpected results from my tranny service this weekend that are related to this discussion and may help someone.
Owner of a A6 (c4) ’97 avant quattro with 126k. All serviced: Oil change every 4k (5w30 mobil1 ep), fuel filter, 3 differentials (mobil1 75w90) and the yada yada ya…..All service up to date. Live in cold Michigan and tranny was taking its time shifting on cold mornings and slowing down on intersections it was shifting down to first gear with a hardly noticeable “thump”, making unnecessary to apply the brakes…so A LOT of retention. Other than that, no noises or issues with the transmission at all.
Bought the ATF (automatic transmission fluid) kit form Blauparts, with the Mobil1 Synn fluid. Did it the job this Saturday (02/0910) with 126k on odo. The previous filter had a stamp on it dated from 23NOV2000..That’s 10 years ago. Fluid appeared black (not as bad as I expected) and pan magnet didn’t show metal particles upon clean up. Placed new gasket and o-ring, pumped up ATF and 7.5 oz of Lubegard Platinum (that’s 1oz for every quarter of ATF on system). Drained everything on a rated bucket (liters/quarts and ml) so I knew how much to put back. Took about 3.5 quarts of the mix.
Went for a drive and shifted like new, slowing down retention disappeared and cold mornings……well, that’s when the It would rattle like rocks in a aluminum can until the car warmed up showed up. It happened Sunday and today, morning only…. I was pretty scared (and felt pretty stupid about changing something that worked “ok”) until I read this thread, (love ya’ Jonathan and Michael) now I decided to do nothing about it and live with it for the next 30k miles until I do my next pan drop. Unless someone has a better idea…..

Thanks. A happy camper.