Its a huge issue on all BMW 4 cylinder petrol and diesel engines from 2006 - 2010, BMW are trying to hide this issue but not managing, start doing your homework on the internet and you will see its a massive problem and BMW should man up and admit once these engine get miles on them that the chains are stretching on cars that have been diagnosed in time and that the chains and tensioners are breaking up ones that haven't. Your car will have shown minor symptoms such as cold start rattle in the morning, slightly rough idle on tick over but its not easy to notice as its easy to miss. Chains were for life once upon a time but because of money saving they are letting this great brand down badly, the recall is already out for all diesel engine 4 cylinder cars that were produced from September 2007, IE all the cars that had the stop start function and in time they will have to admit to the petrol 4 cylinder being made of the same garbage components!!! My advice is to not let it drop, the only way this issue will be sorted is by customers complaining in numbers IE internet campaigns and petitions, the reason they are getting away with this just now is because many of these cars have passed to new owners and the new owner just thinks they have been unlucky but its happening to low miles 1 owner cars but because these cars now have a few years under there belts they fob people off, its not right and the chains and tensioners are indeed "unfit for purpose"!!! I wish you well in your efforts and if its any help this issue has indeed been covered by the television program Watchdog. Steve