1st car in my name

We noticed the vibration/pulsation (it's really more a repetitive pulsation than a vibration) on this car prior to purchasing and were assured it would be taken care of for our purchase and put it in the contract. Being an Audi dealer and certified we were confident it would be done. We went to pick up the car and it still vibrated. We walked on the sale and got a call later in the week that they fixed it with new tires and 17" wheels (it had 18s before). We drove it and ended up buying it. All of 100 or so miles and 2 days later, the car is doing it again. I'm going to have to contact the dealer, but I was wondering if anyone had any potential cause of this that I could suggest to them? I really do want the car. It's rock solid up until about 55/60/65 mph range. I'm going to ask if they road force balanced the tires, but I don't have any other ideas beyond that.

audisport1

High speed wheel balance would be the first one would think. But after they replaced the wheels and tires sounds like it might be something a bit more complicated. If you agreed on the dealer having to correct that problem you should go back to them and make sure they stand behind there work.

As far as the "pulsating" goes I had the same problem on my A6 after replacing a blown out tire with a used matching tire. The used tire was the culprit. Possibly the dealer gave you "like new" tires.

h3rmes

Ask the Hunter Technician to print out a before and after report. If after Hunter Roadforce balancing, the vibration remains, it is most likely a:

(1) out of round tire OR

(2) bent rim

Happy motoring,
H3rmes

1st car in my name

Well that didn't work. They road force balanced it and it's still vibrating. My wife brought it in and they didn't give her a printout before or after. The tech drove it again and said it was ok, but it isn't. It's noticeable the higher you go above 60, is more noticeable under light acceleration than heavy acceleration, and 65 mph and light acceleration seems to bring out the peak of its badness. I brought it back today and they said it might be a bent rim, but wanted to do the service when I pick up my plates in 10 days or so. I have a 500 mile drive ahead of me for Easter weekend and, even if it's not a safety concern, it'll drive me nuts that I paid $25k. Gonna try to fight for the problem to be looked at sooner...

SchwarzS6

Can you isolate the vibration to one corner of the car? If so I would swap the tires front/rear on that side and see if the problem moves. And if you do not have directional tires you can move the tires left right. If the problem moves with the tire you have found the problem (either a bad tire or bent rim). If it does not move then there is something wrong with the axle (wheel bearing, CV joint, warped brake disk). It is not surprising that the problem is worse at 65. Every car I have ever owned seems to be worse at that speed. I suspect that in general suspension tuning tends to end up with a resonance near that speed.

Andyiam1234

Did you ever get to the bottom of the issue , was it the centre prop shaft support bearing?

G-Can

I see another one with issue.. sorry Andy, prepare yourslef to never sort it out.

I will say this. Over engineered german crap. all these sxzyt cars vibrate more or less.

kelisko

I concur with what most people said above. Bad tires or bent wheels/rims. Watch this:

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