My niece has a 320d but its some sort of special edition like the Si, Edition Sport, it had BBS wheels. Anyway the engine went (timing chain). Engine has to come from Germany €€€€!
I found two N47 engines but apparently this edition has some tweaks.

N47 Timimg chain = Time Bomb!

Edit: it was one of these:

http://www.ebay.co.uk/bhp/bmw-320d-m-sport-edition