Strange Vibration - E91 330i

[FlatPack]

Anyone got an idea what this could be?

Did a 500 mile round trip this weekend, mostly on the motorway. About half a dozen times while at motorway cruising speed I had a big vibration (like a wheel seriously out of balance), I think it's coming from the back of the car and it slowly built up over a short space of time, stuck around for a few minutes and then faded away again.

I think slowing down to around 50mph and then coming off the throttle completely makes it go away, but can't be sure as it hasn't happened often enough to really test and that's not always a sensible thing to be doing on the motorway anyway. Frequency of the vibration is related to road speed, not engine speed and I think there's a low frequency sound in time with it when it's happening, hard to be sure as the car is shaking so much.

I'm stumped, I don't think any of the obvious candidates would come and go like that. Car is an lci 391 330i auto and has done about 50k miles.

[Rdawson]

Driveshaft guibo?

[andyiley]

As above, or drive shaft carrier bearing, definitely one or the other, not too expensive or big a job that it is not a homer if required.

[FlatPack]

Thanks Sounds like the driveshaft is the place to start then... I'll take a look a decide if I can be bothered doing it myself or not!

[camp freddie]

I recently had something similar on my X5. Turned out to be a sticking caliper.

[FlatPack]

camp freddie said:

I recently had something similar on my X5. Turned out to be a sticking caliper.

I think this could be a winner, NS rear wheel is getting warm after a drive compared to the others.

That's an easy fix anyway