Just been browsing through some threads about the timing chain rattle issue with the N47 engine and saw a video in one that sounded similar to my engine.
I don't know if it's just paranoia but my engine seems to have a similar sound in the background. It's not there on startup of the car but after the car has been revved the sound then appears.
This is the video of the timing chain rattle I saw posted in one of the threads (this is not my engine):
And this is a video of my engine just now while parked in my garage:
The engine has always sounded like that, I just assumed it was a pump making the noise.
If it is the dreaded timing chain rattle then I will probably opt to chop it in for another E92 rather than pay the £2000 repair when it snaps!
Interested to hear from other 320d owners, if everyone elses engine sounds like that then it will put my mind at rest.