[richas]

Edit:

Disregard. I re-checked again with a stethoscope, it's a rear wheel bearing. :-)

2010 E91 115K

I have been experiencing a pronounced whine from the rear at highway speeds. Today I jacked it up and had someone run it up to ~60MPH. I was thinking it was a wheel bearing. Unfortunately I am hearing it from the diff. I have not checked the fluid but there are no leaks.

Any advice on getting a replacement? Are the E90/E91 diffs the same?

Thank you
Rich

[ppointer]

I have had rear wheel bearings go bad on two of my e9x's. One was a 2009 e91 with 130k miles on it. I bought the wagon with 125k miles on it, so no knowledge of the maintenance prior to that. The other is a 2011 e90 that now belongs to my daughter, and needed the repair at about 77k miles. The e90 I bought with 16k miles and owned for ten years before moving it to the daughter, and it has been over-maintained.

I haven't heard of many failures of the differentials. So, my suggestion is to get a diagnosis from a BMW-certified technician before you throw any money at it.

[Runnin'Rich]

Can you explain in more detail how you diagnosed it with the stethoscope please?

Did you run the car on stands with the wheels off? Then touch the probe to the rear hub?

Could you feel any side to side play in the wheel? Or just noise when rolling?

I have a similar issue with my car,

Thank you

[richas]

Yes, I ran it on four jackstands up to 60 mph. Disable stability control if you don’t want to get a bunch of errors.
I mistakenly took the normal hiss sound of the differential for the whine I was hearing. I use a stethoscope with a long metal probe and touch various places, putting it on one rear brake backing plate I hear almost nothing, on the other backing plate I hear the exact whine I hear at high speeds. The hiss of the differential bearings is normal.
No side to side play.