One problem related to loud engine noise has been reported for the 2009 BMW 335. The most recently reported issues are listed below.
The contact owns a 2009 BMW 335xi. While driving 50 mph, an abnormal noise was heard and the reduce engine power indicator illuminated. The contact lost control of the vehicle and it fishtailed into a ditch. The vehicle was not diagnosed or repaired. There were no injuries and a police report was not filed. The manufacturer was not notified of the failure. The failure mileage was approximately 108,000.