It was a rock!

[Aronis]

Other thread deleted. M2 is aok.

First thing I suspected was a rock against inside edge of rotor. I took off the wheel but did not see anything.

Then suspected bad bearing.

Looked more aggressively and flexed rotor backing plate. Stone fell out.

I was correct but did not persist.

Very happy

Mike

[nene]

Common issue on the latest Bimmers. Our M4 had the same issue and I just flexed the dust plate through the spokes and no more metal grinding.

It has been interestingly named the 'Tin Can Noise'.
Le Tin Can (http://f80.bimmerpost.com/forums/showthread.php?t=1052226)

[Aronis]

Nene,

Can you be more specific on the flexing. How much is too much?


I just flexed mine back enough to get the stone out. I think it is supposed to be very close to the rotor to make entry more difficult for stones.


I have seen this before on other cars, but not that common.

Mike

[nene]

I think I flexed it about 1/4" or less. It really was just a little bit, not much.
I used the stick end of my wheel cleaning brush (plastic stick). It was long enough, and I pressed the edges towards the center of the car in about 4-5 different points. The dust plate is not all around the brake disk, and you really only see about 1" or so protrude above the disk brake itself.

http://htms.org/img/032015/GravelSite/DSC_3552-22.jpg

[lswing]

Common issue on the latest Bimmers. Our M4 had the same issue and I just flexed the dust plate through the spokes and no more metal grinding.

It has been interestingly named the 'Tin Can Noise'.
Le Tin Can (http://f80.bimmerpost.com/forums/showthread.php?t=1052226)

And I thought it was because of the exhaust note...