Timing chain problems
The N47 engine family is prone to excessive timing chain wear and premature failure. Rattling noise from the rear of the engine is indicative of the condition. Timing chain failure may call for engine replacement or a costly repair. The most seriously affected units which require the most extensive repairs were produced from 01.03.2007 to 05.01.2009. However there have been frequent reports of timing chain failure in 1, 3 and 5 series BMW engines manufactured from as early as 2004 until at least 2011 in both the petrol and diesel versions (and hence not just necessarily in the N47 engine). At times the failure has resulted in a dangerous cut out of the engine while the vehicle was being driven - sometimes at relatively high speed. A "Quality Enhancement" was issued by BMW for some, but not all vehicles, but has since been discontinued.