Check the oil pump for debris. There are situations where the serp belt will shred, and get sucked into the pan via the main seal. Crazy but true.

It would be very unusual for an n54 to fail like that, theyre excellent engines outside of HPFP (which should have been replaced) and some vanos issues.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth