This cylinder head gasket seals the combustion chamber between the engine block and the cylinder head. It prevents the leakage of combustion gases, engine oil, and coolant across the sealing surfaces. The gasket is a single-use component; it compresses during initial torquing to conform to the surface finish of the head and block. On reinstallation of the cylinder head, a new gasket must be fitted and the head bolts tightened to the specified torque sequence and value. A failed gasket typically allows cross-contamination between coolant and oil passages or a loss of compression, which results in overheating, misfiring, or external fluid seepage.