Hi James,

It’s not a changing issue so much as a servicing one. The problem isn’t actually with the timing chain itself but with the sprocket linked to the crankshaft that drives the chain. It’s a known weak spot, and while BMW updated the engine in 2008 to try and fix the problem, it can still give trouble, The best advice then is to keep the engine serviced every 10,000km on the button and be choosy about the grade of oil used – insist on the best. Also, and this is possibly apocryphal, but automatic models seem to have a lower failure rate as their gear changes are more sensitive.