This valve cover gasket seals the gap between the cylinder head and the valve cover, preventing oil leaks from the top of the engine. It sits in the machined groove of the cover and compresses against the head surface when the cover bolts are tightened. A failed gasket allows oil to weep onto the exhaust manifold, producing smoke and a burning smell. The gasket is manufactured by AGCO to match the original sealing profile, ensuring it seats correctly in the cover groove without requiring additional sealant. On reinstallation, clean both mating surfaces and tighten the cover bolts in the sequence and to the torque specified for the engine.