I recently purchased a used 2001 C5 coupe with an A4 Trans, it only has 15000 miles on it There are a few things about it that I just wanted to check with more experienced drivers may have encountered. Since it was hardly driven I changed all the fluids in the car and flushed everything out, so I know all the fluids are in good order. The issue that I am having is a faint clunking feeling/sound coming from the rear end of the vehicle. This happens primarily when in reverse or a drive gear sitting at idle (foot on brake idle @ 500rpm) it does not happen all the time so it is somewhat intermittent. If I give it some gas and get the rpms up a bit say 1000 or so it will disappear. (or so it seems)

Also question #2 is when you really get on the gas at WOT I get what feels like a light vibration through the vehicle at high rpms (this may be normal due to the power, but again I have never owned one or know anybody with one to compare) It also seems like the A4 shows some sluggishness to shift at the higher rpms at WOT, this seems normal comparing it to other cars, but again just thought I would ask.

Sorry for such a long post and so many questions from a new individual, hope someone here can clear some of these things up for me so my mind can rest that my new toy is in top working order. Thank you!

 

Anyone with any thoughts for a new C5 owner?

 

with out actually hearing it or feeling it, one can only guess that it maybe
related to the tranny. You say you noticed a vibration on the car at wot
so it also leads me to believe you could possibly have a problem with the
torque tube bushings. These bushings take place of regular u joints in the
driveshaft. These have been known to fail and cause clunking sounds
and vibrations. Do a search on the forum on torque tube and tranny tons
of info to read.

Somebody may chime with a better thought this is my speculation,

 

I agree.. have the torque tube bushings checked/replaced. Also check your rear-end fluid while you are at it. Look at the driveshaft CV joint covers for tears.

 

I'd bet that the clunking you're feeling is the splines on the CV joints, rust from sitting so much. Do a search for rear wheel poppping fix, if you can't find it PM me your EMail address.

 

If you said that the clunking noise happens while moving or turning I would definitely suggest looking at the sway bar end links. Your year has the hard plastic end links from the factory and when they go bad it sounds like a clunking noise. I replaced all four of mine with the upgrade cast alluminum ones. Since the noise also occurs while sitting idle, I'd agree with others recommending to check your cv joints.

 

After some research on the web regarding the torque tube, I am being led to believe that that may be my starting point to find the issue.
Here is my reasoning, since the clunking feeling only seems to occur at idle in drive or park (not while moving) it has to be a part that would be moving at this time. I also read an post on another board about bad TT bushings causing some vibration at higher loadings (like I seem to be experiancing)

 

Also consider your exhaust. Lots of folks have the internals of either cats or mufflers that are loose and vibrate at certain rpms. Make sure also, since you have an A4, that your over axle pipes are not hitting the tranny heat sheilds. Just something to check, although I believe the other posters are correct with the TT bushings, especially on a 7 year old car that has been stored alot.