Originally Posted by AdrianSi
Pre LCi 330d's have the 'bulletproof' engine. The M57 with the revised swirl flaps... I don't think there has been a reported swirl flap failure in a E90. That's pretty much the only thing that killed the engines in E46 330ds.
This said, mine was a very early N57 engine so possibly they 'revised' the design of the guides. When I check the part numbers fitted on the online catalogues I don't remember the being any superceeded parts.
It is still a great car and great engine but definately not a characteristic that should be present in such an engine. I would rather have a front mounted serviceable Cambelt that you expect to renew at specified intervals. Timing chains shouldn't require any servicing, certainly not within 150K...maybe at higher miles 200-300K which will only account for a small percentage of E90s in the future.
So 2007 / early 2008 330d sounds the best bet?
With correct servicing you expect a BMW of being capable of doing 500k, you expect a quality product that is capable of lasting if you do that mileage!
As you said, front access cambelt would be so much easier, changed at the right times there are far far fewer failures.