15638 - Customer Satisfaction Program. Certain 2016 model year Cadillac Escalade, Escalade ESV, Chevrolet Corvette, GMC Yukon Denali and 2015 Cadillac Escalade ESV, Chevrolet Silverado LD, GMC Sierra LD, and Yukon Denali XL model vehicles equipped with 6.2L engines (RPO L86 and LT1) may have engines built with cylinder head gaskets in which the head gasket stopper ring was off location. The gasket may fatigue over time leading to the possibility of a leak into the combustion chamber after several thousand miles. Possible symptoms include: a check engine light for P0300 Misfire, possible combustion gas leaks to coolant resulting in overheating, over-flowed coolant bottle, milky-colored engine oil in the crankcase, piston scuffing and if the vehicle is continued to be driven in this condition, engine failure. Dealers are to replace the left and right side engine head gasket.
