BMW 3 SERIES M SPORT

BMW with rattle from chain
BMW with rattle from chain

This BMW M Sport six cylinder was recovered in due to a front suspension coil spring broken which, because of the way that is snapped, made the car undriveable. We replaced the broken spring which was reasonably straight forward. Once the coil spring was replaced we started up the engine to road test and we noticed that the engine was rattling quite loudly. Experience told us that the timing chain was worn and therefore noisy. We decided not to road test the vehicle as we didn't want to cause any damage to the engine.

If we or the customer had continued to drive the vehicle then there was a high probability that the timing chain would have snapped or come of its guides. This would have meant an engine failure which may have resulted in the vehicle being written off or a complete engine replacement (very expensive).

We spoke to the client and he said that he had heard the noise when he started the vehicle up but it went away after the engine warmed up.

Engine out
Engine out

He agreed for us to start stripping down the engine to replace the timing chain components. We pre-warned him that the cost was quite high but we all agreed that it was worth doing.

We had to remove the engine to gain access to the timing chain.

We replaced the chain and a whole host of other gaskets, bolts and auxilary items. We replace the engine oil and oil filter. Refitted the engine and started it up. The engine sounded sweet and was back to as it should be with no nasty noises.

This is a huge and complex job but everything went to according to plan and the car was back on the road within a couple of weeks.

Rattle on BMW
Rattle on BMW

The pictures show all the components that were removed and I am pleased to say that once the job was completed there were no components, nuts or bolts left over!