My engine had 345k km just before the chain has cracked... But just before the crack:
Oil - Yes when reving much it eats 0.3 ltr/100km, when using it normally - no oil consumption spotted.
Compression -> 13 so perfect... On every cyllinder!!!!
Cyllinder surfaces not worn anywhere. Pistons not bad at all - but it feels that rebuilding the engine needs a new set.
Head - no cracks, just one combustion chamber damaged due to cams-stop.
The BMW made great work, constructing the M42
