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.

DaveInSaltLake

and how worn were the rear tires at the time?

The general opinion is that ignoring Audi's recommendation to keep tires at less than 1/8 diamter difference can wear the center differential. I read one account where long term abuse lead to a catastrophic failure. Searched but couldn't find the post today.

I'd recommend finding a GOOD indy shop that specializes in Audis for an assessment/opinion.

austinado16

First of all, when are you getting this "vibration?"

If you feel a pulsing or rhythmic vibration during braking, then that would be warped rotors......not calipers. If that feeling is in the steering wheel, it's the front rotors. If it's in your seat, it's the rear rotors.

If you feel a vibration during slow tight corners, like say leaving a stop and making a left or right turn through an interesection, or during parking, etc. then that is sort of a normal Quattro thing and many of us have it.....including my Avant.

If you have a steady vibration at speed, then that is going to be from several sources.
1) Tires, including tread design, out of balance, out of round (oval), really heavy on one side because they're cheap, etc.
2) wheels, including bent wheels, wheels with damage of some sort, or a poorly made wheel that's really heavy on one side
3) CV joints, the axles need to be removed and all the joints cleaned inspected and replaced or repacked as needed.
4) CV joints on the driveline. They never get serviced and the grease in mine looked like black clay, not like grease at all.

Take a look at the weights used to balance all of your wheels. If you have anything over about 1 to 1.5 ounces on either side of the wheel, that's your problem. A good tire store will rotate the tire on the wheel until the heavy spot on the tire is opposite to the heavy spot on the rim. This allows the tire/wheel to self balance better, and the use of less weight.

sebou

Well in fact, I replaced the front ones with goodyear tires, I was getting upset about changing the rear ones 1 months after the front ones, as tehy were still good (More than 3 mm profil on the tires) so that I purchased cheap ones. To that time I didn't know the tires had to be the same on all the four wheels and the guy at the shop said they would be ok for the Audi. After they went bad I changed the back ones to the goodyear too. So that now I have 4 new goodyear tires on the car. the wear difference between front and back must be about 3000 km.

In fact the vibration is more coming from the rear of the car, I feel it in the seat not on the driving wheel. I can feel it almost all the time at different frequences. The most between 80 and 100 km/h around 50 to 60 miles/hrs

Thanks for your help.