Model Year 24/25 Random Vibrations with high speed

[Sivva]

Hey, I’m the owner of a Formentor 1.5 etsi facelift, mileage 3000 km.
It was actually first time when I had opportunity to drive it outside the city with highway speeds. I noticed when I reached around 120 km/h and faster I felt kind of vibrations inside the car, I felt it on my seat, my passenger felt it too. It was appearing randomly when I was hitting the accelerator or any other time, absolutely randomly. Anyone encountered with such a thing?

 

[Joolstdi]

Hi that would be on rear end and it could be a puncture or wrong pressure in one of the tyres or a wheel bearing or a suspension component needs replacing or a wheel weight has come off

 

[tomek_olo]

I have it the same. But only on winter set of wheels. Had them rebalanced multiple times.

I've gave up trying to figure it out. Right now the vibrations are so minor, that I can live with them...

 

[Sivva]

I have it the same. But only on winter set of wheels. Had them rebalanced multiple times.

I've gave up trying to figure it out. Right now the vibrations are so minor, that I can live with them...

For me, actually I don’t know if this issue happens also with summer tires because that time I didn’t exploit my Formentor much because I run my engine in and then I changed tires

 

[SRGTD]

For me, actually I don’t know if this issue happens also with summer tires because that time I didn’t exploit my Formentor much because I run my engine in and then I changed tires

Do you use a different set of (aftermarket) wheels with your winter tyres? If so;

• is it possible that one of those wheels could have suffered damage? (e.g. buckled through pothole damage or impact with objects such as a raised drain cover).
• has the incorrect type of wheel bolts been used? (many aftermarket alloys use bolts with a conical seat. VAG alloys use bolts with a radius / ball seat).

Both of the above could cause vibrations.

Additionally, some VAG cars can be susceptible to vibration if the wheel bolts aren’t tightened in a star sequence - like in the picture below. Some tyre places might not do this, and they might also over-tighten the wheel bolts with an air gun rather than using a torque wrench set to the Cupra’s specified torque setting.

The bolts should initially be tightened finger tight when the wheel is still raised off the ground, then tightened a little more (but not fully torqued to the correct setting) with a socket wrench. Then lower the car to the ground and tighten to Cupra’s specified torque setting. All bolt tightening stages should be carried out in the star sequence as per the above diagram to minimise the risk of vibration.

 

[tzuicomicina]

I had the same issue with aftermarket wheels. The tyres, Kleber Krisalp HP3 225/55 R17, couldn't be balanced properly and the car had strange vibrations at high speeds after multiple balancing tries. Sent the tyres back for warranty, they accepted them as faulty, and I was given a refund so I got Michelin's instead.

 

[tomek_olo]

I went through this whole cone/ball investigation. I use aftermarket wheels, but they have the same bolt seats as OEMs. I myself tightened them in a star sequence using a torque wrench. Also a service did it for me. Did not change much.

I suspect tyres are faulty. I use Pirellis Sottozero 3.