The engine valve is made of aluminum and alloy steel. The valve is composed of a valve head and a rod; the intake valve is generally made of alloy steel such as chromium steel and nickel-chromium steel, and the exhaust valve is made of heat-resistant alloys such as silicon-chromium steel; sometimes in order to save heat-resistant alloys, the exhaust valve head Use heat-resistant alloy, and the rod is made of chrome steel.

The valve cover is mainly connected to the cylinder head of the engine. The camshaft is installed under the valve cover, and some parts of the intake mechanism on the cylinder head are sealed to ensure the normal operation and lubrication of the engine's valve drive mechanism. The dust-proof seal forms a closed whole with all parts of the engine to ensure a good working environment for the internal parts of the engine. Here are the effects of a broken valve cover:

1. Affect the lubrication of the vehicle. The oil leaked from the valve cover will cause insufficient lubrication of the valve chamber, which will cause the wear of the parts and damage the engine for a long time;

2. Affect the air tightness of the engine. The working air pressure of the engine will also leak out where the oil leaks. The engine has an exhaust gas recirculation valve connected to the throttle. The air leakage will affect the stability of the engine;

3. It causes the engine to be dirty and even cause a fire. The leaked oil will flow along the engine and combine with dust to form sludge. If it encounters an open flame, it will ignite the engine, which is very dangerous.