By replacing the Mazda valve cover gaskets and seals on your engine, the entire area under the hood of your vehicle will be cleaner and look better. The result of not proceeding with this repair procedure after this engine sealing component t has failed is a mess since the valve cover is the upper most portion of the engine. In the past, replacing the valve cover gasket was a routine procedure and very common on Mazda engines. This was before the valve train had hydraulic lifters placed in them and periodical adjustments were required. Today, the only reasons for the replacement of this engine sealing component include stopping an oil leak or changing it when the head has been removed. The Mazda valve cover gasket and spark plug seals are made out of a polymer that will become brittle as they age and crack; ultimately leaking oil if left unattended. Since this engine component is on the upper most section of the engine, all other parts below it will then be covered with oil. This could then interfere with the operations of the many Mazda sensors and other parts that could be adversely affected by the oil and the dirt that will accumulate. The hardest part of replacing the valve cover gaskets and other seals is getting to all of them. On today's Mazda engine, there are many connections and components that are on or near this engine part. Once access is gained then the removal of all the old valve cover gaskets is required. Once in place on your Mazda, the torqueing down of the components that are sealed by the valve cover gasket must be down in a way as not to be too great so the polymer material is not smashed which would cause a new oil leak.