Ok guys – this is a common issue affecting all diesel cars, not just bmw.
Its simply down to the crank pulley rubber material perishing with age.
Here’s the Car in question, a lovely Imola Red Coupe.
Here’s the crank pulley that has broken up, the belt didn’t fail which is very lucky.
Here’s the pulley removed from the car, the outer piece has torn away from its rubber.
Here’s the new pulley against the old one.
New crank pulley installed on the car.
To replace this pulley you’ll need a very long breaker bar to loosen the crank pulley. This is extremely tight.
You’ll also need the BMW flywheel locking tool to stop the engine rotating.
Using a ‘drill bit’ is NOT recommended.