bad vibration from the rear feeling in the seat

[sebou]

Hello, I bought my Audi A6 2.8 Quattro last January. Soon after I had a puncture on the front tire, I changed both fron tires and soon after that began feeling a vibration in the car. I had the front wheels rebalanced. Nothing changed as I thought that maybe the tires had to adapt I left. Unfortunately it didn't get better, during my timing belt change I asked my VW dealer to check the vibration and he told me it came from the back tires that were ovoid. So I changed the back tires. Still I could feel the vibrations and I noticed it more coming from the back. Soon after that my rear calipers had to get changed and I thought this might be the problem for th vibration so I changed the rear calipers, the rear rotors and the rear pads. Still I felt the vibration so I decided to go back to my VW dealer and balance the back wheels which he did, but told me that the rear tires were ovoid. As I had an insurance on them I went to the place that replaced them first and asked them to put me new tires from the same brand as those in the front. Now I have 4 new tires, new brake system and I still feel a vibration, I don't know what to do. Anybody has a clue? thanks for the help.

[nothing77]

head scratcher, first thing to do is stop listening to your VW mechanic, he is costing you a fortune in possibly unnecessary repairs. Is there any chance you might have a small bend or twist in one of the rear wheels. Any chance you might be able to try on some other wheels for a test run. If you do that and the problem still persists, at least you can rule out the wheel and tire combo. Next start looking at the suspension. Let us know

[bituerbo]

Could be a bent rim, although that should show up when getting the wheels/tires balanced.
Take your car in for a 4-wheel alignment. If it's out, they will likely inspect for free to tell you what part needs replacement/adjustment.

[Black_RS4]

could it possibly be that the wheel bearing is gone? Thats probably the only thing I can think of other then a faulty shock...

[DominikA6]

does the vibration disappear during cornering? does it get worse while braking? what speed does it begin, does it get worse with higher speed or stay relatively the same?
could be the rear suspension bushings are shot that or an axle is going out.
A blown axle (cv joint) with cause the axle to vibrate like crazy and you'll be able to feel it while driving. All you have to do is grab the shaft ans see how much play there is. There should be very little. If you can wiggle the shaft, more than likely, the axle is gone.

[Markio]

Found the problem already? I have the same problem with a A4 Avant Quattro 25tdi tiptronic.....

[Snow Rocket]

Anyone inspect for bent drive shaft and cv shafts?!? maybe siezing u-joint. I have homemade spacers on my winter wheels to clear the calipers, and it is almost impossible to center them correctly. this always causes a vibration as the wheels are not centered on the axle. Also, lift the car and spin the wheels, i haved seen new tires that were stored on edge, and had flat spots - same effect as off center wheels. Wheel balancing machines can not detect this, unless it is a "Hunter roadforce" machine.

[james knopp]

How many Miles are on it and has anyone checked your rear suspension? Your shocks or rear components could be going bad. "Usually" any vibration felt through the front seat backs indicate a problem in the rear. If the vibration is felt in the steering wheel "usually" start looking up front. A friend of mine has an A4 and wore out his rear tires due to bad shocks.