After how many miles do you have to change the timing chain on a BMW 730D?  If you change it once after how many miles should you change it again (on high mileage cars)?

Morning

Your engine is N57 which if memory serves has a lower timing chain and two upper chains that drive the cam shafts. Changing them and their associated guides and tension devices is major surgery. So would not be a normal service item.

Having said that the BMW 3.0d is recognised as one of the worlds great engines and generally is as tough as old boots. However like all mechanical devices even with correct maintenance some times things break but normally if looked after these engines are capable of achieving massive mileages. My brother inlaw has a 535 touring which he uses for regular commutes into Northern Europe 317000 kilometers and no issues so far other than failing diversity antenna's. 

Dave

 

Thanks for that Dave. Very helpful (and reassurring)