Rattling sound from engine?

I have a 99 318is coupe and in the morning it starts grand and no noise from engine as such. when engine is warm and im changing gear when pressure comes off engine its lets a loud couple of knocks from engine. If i have car stopped and jus rev it the knocking comes in about 2500rpm and goes again after 3000rpm. Any ideas?? thanks

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW E30 Coolant Temp Sensor Replacement

[Wayne 962]

Problems like these are very difficult to diagnose over the Internet, but I would guess that it would be a chain tensioner that is beginning to fail. Replacement isn't too difficult. I can't think of anything else that would be obvious.

- Wayne