I had a very similar problem and it turned out to be a twisted or broken belt in the tire. It was the strangest thing, the tire would balance out correctly but when put back on the car it would act up intermittently. It rarely caused problems with coldtires butafter warming up I would get this strange wobble at certain speeds above 55MPH. every so often it would cause a wobble at slower speeds as well. I finally replaced all 4 tires and I have never had a problem since.

 

hmmmmmm........ I am officially confused.

I guess I'll start w/ the tires first? I called Euroteck in Marietta, GA today and talked with a guy named Kenny. It was towards the end of the day and he said he'd have to get back to me. I hope to hear from him tomorrow w/ some ideas on what it might be. I had this pinned (just a hunch) that it would be CV joints.

Thanks all for the advice. Please keep it coming.

 

78,000 miles the outside boots are likely ready to let go on the CV joints if they haven't already. You will have grease all over inside the rim area. Expect to change them.They just let go on my daughters Passat at 68,000 miles. I just replace the entire shaft, inner and outers CV's from the local parts store for about $125 each side if I remember. They let go on my 02 A6 around 75,000 miles. The shake is coming from your tires though. That will happen about every 20-25,000 miles. That is about all a set of good tires will last before they rattle your teeth out.

 

25k is all I can expect out of tires on this car??? Why would that be???? Thats horrible mileage.

 

Yep, I put 114,000 miles on my 02. And it was like clockwork. 28,000 is the longest I got out of a set. I don't know why but these cars are very hard on tires. Now we'll see how my new c6 version is. It appears like it might be better but I've only put 10,000 on the car so far. We'll find out down the road. Any other brand of vehicle I've had could go 60-80,000 miles. Maybe the lo-profile, I don't know why but they eat them for breakfast.

 

Well I am leaning more and more towards tires and wheels (not that I haven't heeded your advice Knapp)

I took it into another tire shop on Saturday and had them do a tire balance and rotation. They also checked the CV joints and found no tears in the boots. Long story short is the shutter in the wheel is now at a different speed. It doesn't "kick in" until 58 mph whereas before it was as low as 45 mph.

This leads me to believe a tire issue, correct? The shop said they tested thewheels and couldn't see any bends, although I cant vouch for how scientific their check was. He saidwhile spinning the wheel on the balancer they place a marking device next to the wheel and see if thewheel bumps the marking device while the wheel is spinning. Does that sound like a good way to test the wheel?

 

That is what I have been trying to tell you. Tires, Tires, Tires!!!!!!!!!! Change to some quality tires and have them installed at the Audi dealer with a road force balance. Then be prepared to do it all over again at 25,000 miles. Been there, done that, many times over.

 

What tires would you recommend Knapp? I am in Georgia (atlanta) so I don't need a tire thats good in the snow.

Also, was thinking about upgrading to a larger size wheel. Will this help the scenario or make it worse? What size wheel would you recommend?

 

I wouldgo with nothing larger than a 17" wheel on the C5. Stick with factory OEM wheel's!I have a set (5) of perfect wheels and tires off a 05 3.2 A6 that I had on my 2.7t that I took off before trading the car in if your interested. 4 have near brand new 235/45/17 Yokahoma H4's on that have only 1800 miles on, and the spare is the origional Pirrelli P6 brand new never run. The wheels are perfect and have never been curbed, they are like new! The Yokos were installed by the Audi dealerwith a road force balance. I can take pics for you if interested. $800 for all 5 wheels and tires. Can't beat that deal, ready to bolt on.

 

^ If he's not interested, I am. Please send some pics along asap. Thanks in advance.