2005 A6 4.2 Intermittent Vibrations from the rer
10-26-2011, 10:04 AM
#11
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In my case at least, the noise is under light throttle in 6th and 5th gear. It _feels_ like rumble strips. When I used VCDS to log the data, there's a fluctuation between engine RPM and Transmission RPM when this happens. I'll try to post a graph of the data later, but it sure seems like the torque converter clutch is 'shuddering'. No codes set, though, and if the RPM's go above 2k or heavier throttle, the problem goes away.
10-26-2011, 12:09 PM
#12
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In my case at least, the noise is under light throttle in 6th and 5th gear. It _feels_ like rumble strips. When I used VCDS to log the data, there's a fluctuation between engine RPM and Transmission RPM when this happens. I'll try to post a graph of the data later, but it sure seems like the torque converter clutch is 'shuddering'. No codes set, though, and if the RPM's go above 2k or heavier throttle, the problem goes away.
10-27-2011, 08:17 AM
#14
ok protofly, this sounds exactly like my problem, i get the strip rumbling at the low rpms between 1800-2500. just had it checked over today by a guy that does transmissions, and he confirmed that it wasn't the transmission fluid lvls but that the tranny had to be rebuilt or replaced. He quoted me $1500 for man hours and $3500 for a rebuilt tranny. Much better than a $8k+ quote from the dealer. But still. for a 05 car that's worth maybe 15K now....damn....
I'd probably have the fluid and filter changed first, before laying out the coin for a rebuild.
For me, I'm STILL waiting on the dealer to confirm whether or not my transmission ever had the new 'blue' fluid and software update applied, as it certainly makes a difference in what fluid I will change to. I'm not averse to going to the dealer to have it done, but at least for this dealership, the answers that I'm getting to my questions aren't confidence inspiring. They don't even seem to want to acknowledge that such a TSB exists! (Guess I have to get off my butt and contact a different dealer about it)...
Do you know if your car ever had the transmissions software updated and the newer fluid? The TSB that Kevin Gary cites _does_ deal with the rumbling/shuddering, and refers it to being related to the torque converter clutch lockup cycle. Who knows? It might solve both of our problems if the update and fluid has never been applied.
As an aside, I've been researching the issues around these transmissions. Most of them seem durable enough, but have had a few issues with software/fluid, and in more than a handful of cases, the torque converter has a seal that fails, and then can also cause the problems we are seeing. There are also some cases of a clutch pack on (I think) 4th or 5th gear which there was a TSB on.
For myself, I purchased my car knowing that I would likely have to do some work to it. So far, the only thing I needed to do was replace the upper control arm bushings, which wasn't a terrible job. If I have to do work to the transmission, I'll also do that myself, up to and including a rebuild, if required. In the end, I've still got less $ into the car than what a new low-end Hyundai Sonata would cost, and the Audi has something that the Hyundai will never have...'soul'...
12-03-2011, 06:33 PM
#15
ok protofly, this sounds exactly like my problem, i get the strip rumbling at the low rpms between 1800-2500. just had it checked over today by a guy that does transmissions, and he confirmed that it wasn't the transmission fluid lvls but that the tranny had to be rebuilt or replaced. He quoted me $1500 for man hours and $3500 for a rebuilt tranny. Much better than a $8k+ quote from the dealer. But still. for a 05 car that's worth maybe 15K now....damn....
Finally had a chance to try and resolve this issue. I purchased 6 quarts of Mercon SP, which is supposed to be an equivalent to the lifeguard 6 chemically. I figured that I have nothing to lose, either the problem gets better, or I'm in for an overhaul anyway.
I decided that I would simple drain whatever fluid I could without dropping the pan, and then top up with the Mercon SP. Drained about 4 quarts out. Replaced a little over 4 quarts, so it was apparently just a bit low. Followed the filling procedure, used VAG-COM to get the transmission to the right temperature, etc.
The fluid that came out was orange-ish in color, very smelly. Probably the original fluid. Certainly not blue.
Driving the car and the vibration that was getting pretty sever is mostly gone. Drove about 60 miles, improved shifting, and less and less vibration. I'll be a ordering the pan gasket and filter, and will likely just use the Mercon SP and do the whole job. It was 40 bucks for the 6 quarts at the Ford dealer.
You may want to try the same thing, especially since you were recommended to rebuild the transmission over what sounds like the same issue. Can't hurt, right?
-Darryl
12-04-2011, 02:13 AM
#16
AudiWorld Super User
Hi timocide,
Finally had a chance to try and resolve this issue. I purchased 6 quarts of Mercon SP, which is supposed to be an equivalent to the lifeguard 6 chemically. I figured that I have nothing to lose, either the problem gets better, or I'm in for an overhaul anyway.
I decided that I would simple drain whatever fluid I could without dropping the pan, and then top up with the Mercon SP. Drained about 4 quarts out. Replaced a little over 4 quarts, so it was apparently just a bit low. Followed the filling procedure, used VAG-COM to get the transmission to the right temperature, etc.
The fluid that came out was orange-ish in color, very smelly. Probably the original fluid. Certainly not blue.
Driving the car and the vibration that was getting pretty sever is mostly gone. Drove about 60 miles, improved shifting, and less and less vibration. I'll be a ordering the pan gasket and filter, and will likely just use the Mercon SP and do the whole job. It was 40 bucks for the 6 quarts at the Ford dealer.
You may want to try the same thing, especially since you were recommended to rebuild the transmission over what sounds like the same issue. Can't hurt, right?
-Darryl
Finally had a chance to try and resolve this issue. I purchased 6 quarts of Mercon SP, which is supposed to be an equivalent to the lifeguard 6 chemically. I figured that I have nothing to lose, either the problem gets better, or I'm in for an overhaul anyway.
I decided that I would simple drain whatever fluid I could without dropping the pan, and then top up with the Mercon SP. Drained about 4 quarts out. Replaced a little over 4 quarts, so it was apparently just a bit low. Followed the filling procedure, used VAG-COM to get the transmission to the right temperature, etc.
The fluid that came out was orange-ish in color, very smelly. Probably the original fluid. Certainly not blue.
Driving the car and the vibration that was getting pretty sever is mostly gone. Drove about 60 miles, improved shifting, and less and less vibration. I'll be a ordering the pan gasket and filter, and will likely just use the Mercon SP and do the whole job. It was 40 bucks for the 6 quarts at the Ford dealer.
You may want to try the same thing, especially since you were recommended to rebuild the transmission over what sounds like the same issue. Can't hurt, right?
-Darryl
12-04-2011, 04:18 AM
#17
Correct. I was never even able to get my dealer to admit that the TSB even existed. They acted as if I was crazy for even wanting the fluid changed.
Why do I get the feeling that the modus operandi of many dealers is to replace the transmission if customer complains about any problem?
Of course, in my case, I haven't got enough miles on yet to know if there is any long term damage that could be caused by the Mercon SP, but I think Turkeybaster's research is probably reliable, and the new stuff has GOT to be better than 130k old fluid!
02-13-2012, 07:41 PM
#19
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Update to my problem
Ok. So, unlike most of you guys that are mechanically inclined, the most tinkering i've done with is with my mountain bike, plus i don't own any tools of my own and don't have a garage. Fluid change is $800 so instead of gambling, I opted to have mine rebuilt for $5000.
After taking the bloody thing apart, the root cause of my problem was the torque converter. I most probably overpaid to get the work done but, I'm also on a timeline to leave the US and need to get the car sold asap. Let me know if you need more details and i'll ask the tranny guy for the specifics.
Cheers,
Tim
After taking the bloody thing apart, the root cause of my problem was the torque converter. I most probably overpaid to get the work done but, I'm also on a timeline to leave the US and need to get the car sold asap. Let me know if you need more details and i'll ask the tranny guy for the specifics.
Cheers,
Tim
04-18-2012, 08:25 AM
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Same here...
I had exactly the same thing happen to me... 05 A6 4.2 at 80k miles. First noticed a slight slip in engine RPMs, but shortly after it started where it would vibrate under light acceleration, particularly noticeable on a slight incline. It was accompanied by the same engine RPM drop, then it bounce back, vibrations stop and everything seems normal.
This would happen in a pattern about every 5 seconds or so. The shop I brought it to replaced the torque converter, which had a damaged seal. Unfortunately the issue persisted after changing this. The engine RPM flux seems to have improved, seems to only bog down when the vibration is occurring.
They contacted ZF, who suggested flushing the cooling lines and changing the filter / all fluid. They had only replaced what the torque converter needed. They claim now that the issue is getting better as they drive it, and want me to drive it for a few hundred miles and see what happens.
ProtoFly, sounds like we had the same issue; hopefully mine improves as yours did. Have you had any issues with it since you changed your fluid?
Thanks!
This would happen in a pattern about every 5 seconds or so. The shop I brought it to replaced the torque converter, which had a damaged seal. Unfortunately the issue persisted after changing this. The engine RPM flux seems to have improved, seems to only bog down when the vibration is occurring.
They contacted ZF, who suggested flushing the cooling lines and changing the filter / all fluid. They had only replaced what the torque converter needed. They claim now that the issue is getting better as they drive it, and want me to drive it for a few hundred miles and see what happens.
ProtoFly, sounds like we had the same issue; hopefully mine improves as yours did. Have you had any issues with it since you changed your fluid?
Thanks!