Ok this is a new M4 with the S55 engine and about 2k miles,,,as you can see the front pulley came loose and started to wobble,,,,and it a nice groove into the front of the engine block.,,,,we thought the big front crank bolt was loose,,,,because BMW has had some problems with that,,,but it wasn’t that,,,,it looks like small torque bolt came loose and caused the problem. What a mess,,,looks like someone’s getting a new engine,,,,the problem is BMW doesn’t have any engine lying around,,,they have to pull one-off the assemble line to get the car back on the road,,,,this job to swap out the engine only pays about 23 hours