Some Vaccumcleaner Motor have Beryllium Bearings,
the Bearings from the Idlevalve look quite same.
Not the shape but colour of the Material it self.

Gude Mario Audi 100 CD Autom. Bj.83 Audi 200 20v Bj.89 Audi 5000 Bj.85 Audi V8 3,6 Autom. Bj.88