Your plastic timing chain guides finally failed. Common problem.

If you are lucky you didn't cause any serious engine damage. You'll have to pull the heads off to find out.

You really shouldn't have kept driving with those symptoms. It's possible you worsened the damage. Worst case you need a new motor, or need to rebuild yours.

New motor options: source a motor from BMW, find a used 4.6 motor (rare), or swap in a 4.4 block.

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2002 X5 4.6is - Titanium Silver / Black Alcantara - Dinan Stage 2 - Bilstein/Eibach - Brembo BBK ----SOLD---
1993 318i - Brilliantrot / Tan - bone stock daily driver