SPS
Moderator
Interesting, i wonder if its your diff mounts, only thing i can think of that could do it stationary.
Chain driven engines rely on lube from engine oil, if a chain rattles chances are its slack (rare) or the chain guides are knackered! Thats a big repair bill!
Make a video of said issues, and ill take a look, on the chances im unsuccessful with my diagnoses, should take it to a BMW specialist, get it looked at
I may be over exaggerating a little as I don't really know what BMW engines sound like up close. But I think I'm going to take it over to these guys anyways http://www.thegaragesheffield.co.uk/