V is for vibration
 

I have had my V90 Inscription Pro (MY19) for 4 months now. I have balanced the wheels 3 times (once dealer and twice at my local preferred tyre specialist). But I still have vibes at speed and not the good type. At 85 mph, cruising the French motorways, at times the vibration is almost as much as the lane departure warning to the point that you can barely notice it. But at other times, there is hardly any vibration. I do not think it is road surface related. Seems to be related to engine power output. Running down a slight hill seems to reduce the vibrations, going up an incline increases them. I’ve tried dropping down a gear, to increase engine revs but this doesn’t seem to make a difference. I have tried different drive modes but couldn’t be sure if they made any difference. Is there some balancing of the transmission that Volvo can do? I love the car but these vibrations are not comfortable and will probably reault in a shorter life span. Anyone else had this? The dealer being based in London are next to hopeless. They don’t actually know anything about driving, only selling you a car that looks cool.

Mine has a little bit of vibration at maybe 75-80 but only really very noticable when the car and the outside temperature is very cold. Once the car warms up it is less pronounced. Always assumed it was cold tyres being a tiny bit out-of-round.

The car has been like this since new? Have you bought it new? Could be something as benign as a flat spot in tires (from sitting parked for a while..)

Front wheel vibration is most pronounced between 60-90km/h and rears between 90-120km/h. I’d start by switching the wheels over (fronts to the back and vice versa..), to see if it will make any difference.

I assume it’s a FWD version V90? There’s only driveshaft balancing- but those vibrations are felt only when accelerating from a stop- and yours is most likely a FWD- so this is probably not your problem.. No such thing as “transmission balancing”..

If there’s no vibrations felt when idling- it’s not engine/transmission mounts either.

Last option is suspension. You have air? Have you had close encounters with a curb/large potholes?

As others have mentioned, I'd think of tyres as main culprits when it comes to vibration. My wife's focus had a vibration which drove us mad. Had it in the garage under warranty again and again tried several wheel balances, new wheel bearings and all sorts. Then got a puncture on front nearside tyre which we replaced and car was perfectly smooth. Must have been a big flat spot I reckon.

I had convinced myself it couldn't be tyres as I was sure it only happened under certain circumstances.

On-car balanced?

It is a V90 D5 AWD version. It is one of those ex-volvo UK cars. When sales are slow they register the cars and drive them around for 6 months before putting them on a dealer’s forecourt. Could a tyre flat-spot cause these seemingly torque related vibrations?

Probably not torque-related but rather speed-related.. You said yourself that dropping a gear (ie. raising revs/torque) doesn't change a thing..

I would try something nice and simple you can do yourself to start with.

Swap your front and back tyres over (keep the sides the same) and see if it is any different.

It is not speed related. Cruise control set to 85. Going up an incline is noticeably more vibey than going down an incline. Same speed. Drop down to 7th, revs go up, same speed. Same bad vibrations.

There are new technical journals about high-speed vibrations:

TJ20803.20.0-2019-03-15 Test schedule for vehicle speed dependent vibrations at highway speeds
https://www.volvotechinfo.com/index....0.0-2019-03-15

TJ34499.1.0-2019-02-26 - Vibrations from wheel arch liner at high speed
https://www.volvotechinfo.com/index....1.0-2019-02-26