S3 vibration mystery!

[ElzLewis]

Hello,
Wondering if anyone else is having this issue..
-car vibrates through the steering wheel above 70mph on certain road surfaces/gradients but then not at other times at similar speeds / round bends and such the issue clears and if travelling above said speeds it seems fine..

Things that have been checked / replaced

Suspension was a brand new ST X coilover kit
Had Brand new wheels / tyres balancing rechecked
New discs and pads all round
Alignment checked / tyres wearing evenly
Everything was checked underneath but that was on an MOT style ramp so car on its own weight may need to try with the weight off the wheels / suspension? .. only other thing I can think of is prop shaft / drive shafts but all seem good and tight.. don’t want to replace things for the sake of it and not cure the issue
If anyone has had a similar issue and cured it I would be thrilled to hear the remedy!
cheers

 

[Daveyonthemove]

No idea.

 

[ElzLewis]

No idea.View attachment 208811

Helpful

 

[Daveyonthemove]

Helpful

Seemed like a good opportunity to share a photo of my car.

 

[samisnake]

my non-s3 (pictured above) has this same issue now and again.
pretty much went away after changing pass side driveshaft, but every now and again on the motorway between 60-70 can feel it slightly.

 

[samuelh_888]

No issues with mine.

Na, my previous A3 (1.8 TFSI) did this - I replaced the steering rack and it was all good.

 

[Ethan1986]

I had the same issue in my Mercedes W210 when going over 55 miles and braking. After replacing the rocker arm bolt the problem is gone

 

[prt57]

In the original post you mentioned new wheels and tyres.
Were the wheels genuine of aftermarket?
Do you have a friend with a similar car that would lend you a pair of front wheels/tyres? There needs to be no vibration on the donor car so at least you can guarantee the balance etc is perfect. If both you and the friend have a spare tyre to put on their car whilst you have the donor wheels on your car this idea will work.

 

[ElzLewis]

In the original post you mentioned new wheels and tyres.
Were the wheels genuine of aftermarket?
Do you have a friend with a similar car that would lend you a pair of front wheels/tyres? There needs to be no vibration on the donor car so at least you can guarantee the balance etc is perfect. If both you and the friend have a spare tyre to put on their car whilst you have the donor wheels on your car this idea will work.

It’s definitely not the wheels , I had the original Audi 18’s on and had the balancing checked twice then got some brand new wheels from rotiform and the issue still persists

 

[ElzLewis]

No issues with mine.

View attachment 208859

Na, my previous A3 (1.8 TFSI) did this - I replaced the steering rack and it was all good.

This is the issue I want to be 100% certain before I start replacing stuff but had it on a ramp and can’t see anything obvious

 

[SootySport]

Another cause of vibration on Quattros is the prop shaft. Either the rubber donuts can go hard or the prop can go out of balance. There has been quite a few instances discussed on this forum in the past. Audi’s solution is replace the whole prop shaft, cost was £1200. If it were me I would have the prop replaced by Audi(they are the experts or so they tell us) and if it doesn’t cure the problem I would insist they refit the original at no cost.

 

[S.]

Got the same issue. I'm also clueless.

 

[ElzLewis]

Another cause of vibration on Quattros is the prop shaft. Either the rubber donuts can go hard or the prop can go out of balance. There has been quite a few instances discussed on this forum in the past. Audi’s solution is replace the whole prop shaft, cost was £1200. If it were me I would have the prop replaced by Audi(they are the experts or so they tell us) and if it doesn’t cure the problem I would insist they refit the original at no cost.

I’m thinking of replacing the rubbers but eve then it’s gonna cost me around £4-500 at a rough guess so not ideal if it doesn’t fix it