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Old 10-06-2009, 08:26 PM
Funf Dreisig Funf Dreisig is offline
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Location: USA
Join Date: Mar 2004
Posts: 405
Mein Auto: 77 530i & 09 35d
Here is my best guess at what happened to your engine....

Assuming the oil was not low, the most likely cause is a material failure of one of the rod bolts. The progressive knocking you heard is probably when the rod cap was working loose and stressing the other rod bolt to the point of failure. Once both rod bolts failed, the now loose rod end was probably hit by the crank shaft slamming/wedging it into the side of the engine block. This would 'seize' the engine dropping RPM to zero instantly.

It would be interesting to hear what actually happened but I won't be holding my breath for full disclosure from BMW about the failure of a 35d engine

Funf Dreisig
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