Supersedes Technical Service Bulletin Group 21 number 12-09 dated May 16, 2012. Rattling and/or jarring noises heard from the engine compartment/exhaust system between 1800 and 2900 rpm. Because of exhaust gas pulsations, the wastegate flap and rods vibrate at the start of the boost air control. This vibration causes rattling or jarring noises.
