Rattle in engine
 

Hi there.
I just purchased a 2008 535xi from original owner with 59k for miles. For $2000. He had to the dealer and they said it’s 5k to repair. The repair order says

. 1. CHECK ENGINE LIGHT CAME ON AND STARTED RUNNING POORLY, HAD AT DEALER AND IS BEING TOLD THE CAM SENSOR BACKED OUT AND WAS LOOKING AT A 5000.00 REPAIR DUE TO OIL PAN NEEDING TO BE REMOVED TO REPAIR BUT THEY WERENT CLEAR ON WHAT WAS

the engine does have a rattle at low end. And there’s metal in the oil. I’m worried I just screwed myself out of 2k. If I just have to remove the oil pan and fix cam sensor I’m good with that. I’m assuming the metal is the cam sensor getting chewed up.
looking for any advice from the 5 series guys/ gals.
Thanks