What is used to seal between the cylinder head cover and the cylinder head?
2 Answers
Between the cylinder head cover and the cylinder head, a sealing gasket is used. Below are the reasons that affect the sealing performance of the engine cylinder head: Incorrect use and installation of the cylinder head gasket: The cylinder head gasket is installed between the engine cylinder block and the cylinder head, and its function is to ensure the sealing of the combustion chamber, preventing leakage of gas, coolant, and lubricating oil. Therefore, if the use and installation of the cylinder head gasket do not meet the requirements, it will directly affect the sealing reliability of the cylinder head and the service life of the cylinder head gasket. To ensure sealing quality, the selected cylinder head gasket must have the same specifications and thickness as those originally equipped with the cylinder, with a flat surface, firmly adhered edges, and no scratches, dents, wrinkles, or rust stains. Otherwise, it will affect the sealing quality of the cylinder head. Slight movement of the cylinder head: The slight movement of the cylinder head is the result of the cylinder head attempting to separate from the cylinder block under the action of compression and combustion pressures. These pressures stretch the cylinder head connecting bolts, causing the cylinder head to have a slight movement relative to the cylinder block. This slight movement will cause the cylinder head gasket to undergo a process of loosening and tightening, thereby accelerating the damage of the cylinder head gasket and affecting its sealing performance.
As a mechanic who frequently tinkers with engines, I can tell you that the seal between the valve cover and cylinder head is achieved using a valve cover gasket. This component is typically made of rubber or silicone—a soft, flat piece that adheres to the junction between the cover and cylinder head, primarily preventing oil leaks. When the engine operates at high temperatures, the gasket must endure thermal expansion and contraction; otherwise, it ages and cracks, leading to oil leaks. A common issue is spotting oil stains around the cylinder head, which usually indicates gasket failure. I recommend inspecting the engine bay every few oil changes. If signs of oil seepage appear, replace the gasket promptly. During installation, ensure surfaces are clean and bolts are evenly tightened to avoid uneven pressure causing secondary leaks. Though a small part, a leaking gasket can contaminate the entire engine and even increase repair costs. Proper maintenance significantly extends engine lifespan.
