Vibration Issue

[Spaceman Spiff]

Hello all. I own a 2015 Volvo V60 T5 Premier 2.5L turbo with AWD and around 53,000 miles. Lately, I've been having an issue where the car vibrates slightly at highway speeds. Over the last several months I have attempted various fixes including countless wheel balances, an alignment, new tires, new wheels (aftermarket and OEM), hub rings, but the issue still persists.

I thought it had something to do with how I was torquing the lugs (raised vs on the ground), but that doesn't seem to make a difference. Last week I installed an IPD wheel stud conversion kit to see if that would change anything, it did not.

One of my local Volvo mechanics basically blew me off saying it would be near impossible to diagnose such a problem. Please, if anyone has any advice I would greatly appreciate it. I love my wagon and would hate to have to get rid of it for such a strange issue.

Many thanks,
Spiff

[IPD-Ken]

This could get pretty involved. First I would try running a different set of wheels and tires. if you are lucky you may be able to "borrow" a known good set from another car. You need to do this to eliminate systems.

It is possible this could be a driveshaft problem or a shock issue, so eliminating the rolling parts as a contributor is the first/simplest step.

[gguayante]

My 2015.5 V60T6 R Series 85K miles has something similar, but it only happens occasionally on long trips and at different (70+) speeds. Usually goes away after a few minutes. It's very slight - can be heard as much as felt. It seems almost like something harmonic, although it's not rhythmic. New tires did not fix. I can live with it until it gets bad and consistent enough to really troubleshoot. Parts are too expensive to try the 'replace and see' method, and until a mechanic can actually observe it...

Now the vibration is more noticeable and happens after the car and tires are thoroughly warmed up at freeway speeds, but only under load or acceleration. After it first appears at 60 mph or so, I can induce it at will at speeds as low as 35, simply by accelerating slightly. New tires (again), new axles, engine mounts appear good. Ideas?