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. 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.
Other issues
The return spring on the turbo’s wastegate was not originally lubricated or covered, this frequently resulted in early failure causing the waste-gate to remain partially or fully open. With the subsequent loss in compression, fuel consumption increased by 30–50%. The problem was described by BMW engineers as a “known fault”.
