I'm not familiar with this particular diesel engine, but I've tested enough of them in my time to make some observations which I have found to be generally valid:
The only long-lived chain configuration I have found to be suitable for a diesel engine is a duplex roller chain, preferably with a hydraulically damped rolling sprocket sprung tensioner. A single chain or a hy-vo type chain will not last much longer than a good belt and is far more expensive to change.
Marginal on a petrol engine, the single chain is over stressed by the need to drive the fuel pump which provides extremely high pressures. The pump also presents a jerky load to its drive which chains generally dislike, especially with a poor design of tensioner.
Best - duplex roller or a geared drive (if you don't mind the noise). Well designed, this will last the life of the engine. Example - early M-B (meets the requirements of para. 2).
Reasonable - a well designed belt drive which is accessible for maintenance. One or two belt changes within vehicle life. Example - PSA HDi.
Worst - single or hy-vo type chain. Requires maintenance with costs out of proportion to vehicle value as the vehicle nears the end of its life. Example - some newer M-B, eg. old A Class.
Find out what sort of chain is fitted to this engine and report back - preferably with details of any modifications which BMW have made.
659.
Edited by 659FBE on 21/10/2012 at 19:09
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