Some 2011-2012 Ford Mustangs (excluding Boss) built on or before 3/31/2011 and equipped with a 5.0L engine may exhibit an intermittent metallic rattle or scratching type noise in the area at the front of the left cylinder head at idle with the engine at operating temperature. This is not described as a typical upper engine tick or tapping noise.
1. With the vehicle in Park, start the engine and operate at idle, allowing the engine to warm to normal operating temperature.
2. Using a mechanic’s stethoscope or EngineEAR, evaluate the area at the front of the left cylinder head. If the noise is heard, replace the left hand primary tensioner and the left hand timing chain tensioner arm using the kit and parts listed below. NOTE: Failure to replace both the primary tensioner and timing chain tensioner arm may result in overloading of the timing chain and under certain conditions could lead to timing chain failure.
P/N ………………………… PART
BR3Z-6L266-AA.................chain tensioner kit
ZC-30................................. Motorcraft silicone gasket remover
ZC-31-A.............................. Motorcraft metal surface prep
TA-30................................. Motorcraft silicone gasket and sealant
BR3Z-8255-A..................... thermostat seal
F1VY-8507-A..................... water pump gasket
BR3Z-6A340-A.................. crankshaft bolt
BR3Z-6020-B..................... front cover gasket (left)
BR3Z-6020-C..................... front cover gasket (center)
BR3Z-6020-D..................... front cover gasket (right)
BR3Z-6584-A..................... left hand valve cover gasket
BR3Z-6584-D..................... right hand valve cover gasket
BR3Z-8620-A..................... A/C Stretchy belt
