BMW of North America (BMW) is recalling certain model year 2010-2011 128i Coupe, 128i Convertible, 328i Sedan, 328i xDrive Sedan, 328i Coupe, 328i Convertible, 328i Sports Wagon and Z4 sDrive 30i, 2011-2012 135i Coupe, 135i Convertible, 335i Sedan, X5 xDrive 35i, and X6 xDrive 35i, 2011 335i xDrive Sedan, 335i Coupe, 335i Convertible, 528i Sedan, 535i Sedan, 535i xDrive Sedan, X3 xDrive 28i, and X3 xDrive 35i, 2010 X3 xDrive 30i, and X5 xDrive 30i, 2012 640i Coupe, and 640i Convertible and 2010-2012 535i Gran Turismo vehicles. In the affected vehicles, the bolts that secure the housing for the variable camshaft timing adjustment (VANOS) unit can loosen over time and may possibly break.