What does a Head Gasket do? A head gasket is a gasket that sits between the engine block and cylinder head in an internal combustion engine. Its purpose is to seal the cylinders to ensure maximum compression and avoid leakage of coolant or engine oil into the cylinders; as such, it is the most critical sealing application in any engine, and, as part of the combustion chamber, it shares the same strength requirements as other combustion chamber components. What type of gasket does Honda use? Honda uses an MLS type gasket which stands for "Multiple Layers Steel". * Most modern head engines are produced with MLS gaskets. These typically consist of three layers of steel. The contact faces are usually coated with a rubber-like coating such as Viton that adheres to the cylinder block and cylinder head respectively whilst the thicker center layer is bare.