XC90 T8 vibration / resonating at speed..

[Keeno]

My 2017 T8 is a year old, it has started to develop a bad vibration at speed, anything above 65mph and it shudders through the seat. I've had the car serviced, Volvo said it was the front tyres (Conti silents). I've had those replaced and balanced, still there. I've had the rears balanced, still there.

it basically makes the car undriveable at high motorway speeds, its really uncomfortable.

Any ideas? Its definitely not wheel alignment, as its not pulling. Feels almost drivetrain related to me....

[Deman77]

If it progressively builds up then yes could be damaged suspension or drivetrain but since you say it only kicks in from that speed it’s more likely aerodynamics.
Possibly something is loose under the car and airflow makes it vibrate.

If you ruled out the tyres, get them to arrange you an equivalent loaner whilst they investigate. If you keep coming for “may be this” visits it will be a long and frustrating process.

[familymangreg]

Originally Posted by Keeno

My 2017 T8 is a year old, it has started to develop a bad vibration at speed, anything above 65mph and it shudders through the seat. I've had the car serviced, Volvo said it was the front tyres (Conti silents). I've had those replaced and balanced, still there. I've had the rears balanced, still there.

it basically makes the car undriveable at high motorway speeds, its really uncomfortable.

Any ideas? Its definitely not wheel alignment, as its not pulling. Feels almost drivetrain related to me....

I'd take it back to the dealer and ask for their master tech to come our for a test drive with you. Take him/her out and demonstrate the issue, explaining that you've had new tyres, wheel balanced etc.. If they still insist its a tyre balance issue, ask them to re-balance at their expense, unless it solved the issue, in which case you can take it up with your tyre fitter. If it doesn't solve the issue, your dealer needs to investigate further under warranty.

:wq

[Exponent]

We had a problem displaying similar symptoms as yours - on a 2016 XC60 - from brand new.

It is in another thread - however the short story - wheels balanced and aligned. Problem remained. Change the full set of tyres - problem gone. Closer inspection - out of round tyre(s). Beautifully engineered vehicle and great driving with round wheels. Love it.

Not stating that it is the problem with your vehicle. But possibly a less expensive and quick check is verifying or discounting any tyre runout. Might save considerable headache - or at least verify it is not the cause of the problem in order to focus trouble shooting.

[Rojah]

Absolutely agree with you. I had exactly the same problem on my 1999 V70. Vibration from rear, noise too. I had a new set of tyres fitted, one of which turned out to be oval. In my case, the tyre was probably unsafe. My XC90 is so super smooth, it would show up any anomaly quickly.

Good luck,

Rojah

[Deman77]

Wow. Would this not be something that tyre fitter would easily spot when balancing the tyre? I understand tyre damage hitting a pothole but new tyre allowed to be fitted like that I don’t understand. Could it be it was ok when newly fitted just had sidewalk weakness defect and deformed shortly after?

[familymangreg]

I wonder if your dealer would be prepared to swap your car onto a set of wheels from a demonstrator or other XC90 for a quick test run, this would easily prove whether it is a wheel/tyre or other issue.

:wq

[Exponent]

Originally Posted by Deman77

Wow. Would this not be something that tyre fitter would easily spot when balancing the tyre? I understand tyre damage hitting a pothole but new tyre allowed to be fitted like that I don’t understand. Could it be it was ok when newly fitted just had sidewalk weakness defect and deformed shortly after?

Firstly - tyre fitter may not give a rats. I would imagine if it was me after that first fifty tyres for the day - a white jacket and a padded room would be bliss! Just banging in on the machine - lets it do its stuff and puts the weights on the laser line. Just because it is in balance does not necessarily mean it will run free of vibration ie. out of round.

In my case - the initial trouble shooting was by borrowing a set of wheels off another XC60. All went smooth. Initially narrowed to the wheels / tyres.

I spotted my out of round when it was on the machine getting balanced. I was dismissed initially when I spotted it. I could spot it by eye when it was rotating. The first step was the balance and alignment. Obviously best to try the least cost issues first - then progress to more dramatic recovery such as changing the tyres.

The Michelin rep made the call to change the tyres after the balancing and alignment didn't help. Not sure who need to pony up for the new tyres - if it was Volvo or Michelin or both - but I am sincerely grateful for their efforts and the manner in which they approached it.

I was impressed enough to go back and buy a second Volvo for the Mrs.

[Keeno]

Problem solved. While it took a bit of pressure and not being fobbed off, the Volvo dealer did a good job of solving.
So it was the Conti silent tyres on the rear. While they were a year old they still had 2-3mm left before legal limit. The foam silencing applied to the inside can come lose - this is apparently enough to really throw the wheels and tyres out of balance. A quick fix of ripping out all the foam, and then rebalancing has solved it. I will not be replacing with Conti Silents...
The car was really bad, I've had loads of 4x4's and I've never experienced that level of vibration even with legal limit tyres / out of balance wheels...and that includes X5's running on 21" ers with battered wheels....
Appreciate all the help and comments - thank you!

[nu11eaf]

Originally Posted by Keeno

Problem solved. While it took a bit of pressure and not being fobbed off, the Volvo dealer did a good job of solving.
So it was the Conti silent tyres on the rear. While they were a year old they still had 2-3mm left before legal limit. The foam silencing applied to the inside can come lose - this is apparently enough to really throw the wheels and tyres out of balance. A quick fix of ripping out all the foam, and then rebalancing has solved it. I will not be replacing with Conti Silents...
The car was really bad, I've had loads of 4x4's and I've never experienced that level of vibration even with legal limit tyres / out of balance wheels...and that includes X5's running on 21" ers with battered wheels....
Appreciate all the help and comments - thank you!

I cant wait for my contisilent tyres to wear down so I can change them, I wont be buying Continental tyres either, (ever) having them on the XC90 has not done their reputation and good at all.