What are the causes of car valve leakage?

[JesseLee]

Reasons for car valve leakage: 1. Wear, burning, spots or depressions, and carbon deposits on the working inclined surface of the valve and valve seat ring; 2. Excessive clearance between the valve stem and valve guide, shaking of the valve stem or bending of the valve stem, and tilting of the valve head, resulting in incomplete valve closure; 3. Weakening or loss of elasticity of the valve spring or spring breakage can also prevent tight fitting between the valve and valve seat; 4. Small valve clearance, after the valve stem expands due to heat, the tappet and rocker arm push open the valve, preventing the valve from fully closing and causing leakage. The valve is an important component of the engine, and its function is to specifically deliver air into the engine and discharge the exhaust gas after combustion.