What is a valve cover ?
The valve cover is a cover plate used to protect the camshaft above the valve chamber and form an approximately closed cavity with the cylinder head (there are also oil return passages, oil supply passages and other oil passages connected with other cavities)
What is the cause of air leakage in the valve cover?
Air leakage from the valve cover will cause the vehicle to be unable to drive. If the mixture is too rich or too thin, the oil in the combustion chamber is not completely burned, resulting in increased fuel consumption. It will also cause the car to accelerate slowly. The engine is difficult to start, the power decreases, the combustion is incomplete, the carbon deposit is serious, and even individual cylinders will not work. Generally speaking, if there is oil leakage, it is recommended to replace the valve cover
Does it matter if the valve cover gasket leaks oil?
The valve cover gasket leaks oil, which still affects the vehicle. It should be replaced in time. The valve cover gasket is mainly used for sealing to prevent oil leakage. If it is not replaced in time, the seal will shrink, harden, lose elasticity and even break seriously. If it is simply the oil leakage caused by the aging of the valve cylinder head, the problem can be solved by replacing the valve cylinder head with a new one. If you buy it yourself, the price is about 100 yuan. If you go to the 4S store to replace it, it will be at least 200 yuan. Valve cover gasket is generally made of rubber, and one of the major characteristics of rubber is aging. Therefore, if the service life of the vehicle is too long, the rubber material will age and harden, resulting in oil leakage. When replacing, pay attention to the following points. When replacing, completely clean the contact surface. Apply glue if you can, because it takes longer to apply glue. It's OK not to apply glue. It depends on the owner's wishes. 2. The engine must be completely cooled before it can be replaced. 3. When installing the valve cover, tighten it several times diagonally. After fixing a screw, go back to the diagonal screw. This will prevent uneven stress on the valve cover gasket.
How does the valve cover look bad?
There are generally several reasons for the damage of valve cover gasket. The first is that the bolt is loose, the second is the engine blowby, the third is the crack of valve cover, and the fourth is that the valve cover gasket is damaged or not coated with sealant.
During the compression stroke of the engine, a small amount of gas will flow from the cylinder wall and the piston ring to the crankcase, and the crankcase pressure will rise over time. At this time, the crankcase ventilation valve is used to lead this part of gas to the intake manifold and suck it into the combustion chamber for reuse. If the crankcase ventilation valve is blocked, or the clearance between the piston ring and the cylinder wall is too large, resulting in excessive air channeling and high crankcase pressure, the gas will leak out at the places with weak sealing, such as valve cover gasket, front and rear crankshaft oil seals, resulting in oil leakage of the engine.
As long as you apply the sealant, tighten the bolts, and the valve cover is not cracked or deformed, it shows that the valve cover is good. If you are not at ease, you can use a ruler and a thickness gauge (feeler gauge) to measure the flatness of the valve cover to see if it does not deform.
