Any TSB for Vibration/wobble issues at speed 75+

[gdallas]

Evening!

Had my used car for just over a week now. Has a bumpy ride post 70. Wheels all balanced, 4 wheel hunter alignment, and whilst wobble at that speed is massively reduced, it's still not as smooth as I'd expect.
Reports of very minor buckling, but negligible as I've been advised from tyre fitters.

So I'm clutching at straws now, are there any known TSB that address said wobble? Could it be engine mounts? Cars only done 13k.

I'm at a loss

C7.5 BiTdi. Black edition

[A6S]

Swap the fronts to the back and see if it’s any better. A small buckle is all it takes for vibrations especially on big wheels and low profile tyres.
Other things to check is defects in the tyre, I had a pair of cheapy tyres on my old car before and the noise and vibration were unbearable even after balancing, tracking etc, got rid of them and got a set of Dunlop’s and all was fine.

[gdallas]

Ye, could be the fact there is an Arrowspeed back right brand new, and and perelli pzero with low to med tread back left? I didn't do that before you have a go lol. Just wanted to rule everything else out before I invest as I can still reject the car

[A6S]

I don’t think it’s recommended to have different tread pattern across the axle on Quattro cars. Also more than a couple of mm difference across the axle and the front to back.
It can damage diffs etc. Well so I’ve been told.

[gav28uk]

I would definitely check out the tyres, I kow it's not the same car, but my son's Fiesta had a dreadful wobble at 70+mph, turns out he had some cheapo Chinese rubber on the fronts! The wheels where balanced and no issues found. Swapped out the tyres for a set of Dunlop RT2 Sport Maxx's and the vibrations vanished. That was a life lesson for him :-)

[Elansear]

Ye, could be the fact there is an Arrowspeed back right brand new, and and perelli pzero with low to med tread back left? I didn't do that before you have a go lol. Just wanted to rule everything else out before I invest as I can still reject the car

Hi. Get rid of the used one. You really should have the same wear across the axle and pattern. To be spot on, all the same on all 4 corners. Was it from an Audi dealer or other source? If from a garage it should not have been sold in that state, or is the tyre change down to yourself? The tyre place should have advised you to have the same across the axle. Not having a go at yourself but for a 150mph car with 4wd is it worth the £300-350 not to have it right. If it came from a garage I would get them involved first, if private, try for some money back but not much chance you would get it. Hope it's sorted soon, then Enjoy...

[gdallas]

Definitely wasn't me who put that crap on. I never scrimp on tyre. I just didn't want to swap them over to new ones whilst I decide if I'm handing the car back.

Anyway, problem solved today. Front wheels which I got balanced last week (allegedly) were both 80g out each! I'll be having words with the first tyre Place. Car running smoothly now. Ps I've only had the car a week.

[Elansear]

Hi glad to hear it's sorted. I think you should have a word with the seller, it should not have been sold with the tyre mix. Had the out of balance wheel had a tyre change around the time it was sold ? loosing a weight these days hardly happens. Time to enjoy now.