Roller Bearing Found In Oil

Stop driving it until the problem is found and repaired.

I would find an independent BMW repair shop and stop by and show them the roller to see if they have any idea where it came from. It is possible that it is a part locating dowel, but not sure. My Dodge Ram, Lincoln and Mercury Marauders engines would contain no such roller bearing within the engine. Not sure if your 7 series engine has any roller bearings in it.

Do you know for certain that this came out of your engine oil or was it found in a drain pan that other vehicle's oil was drained into?

I wonder if the bearing was part of the valve train.

You ever figure out where it came from?? I have the same issue!!