The engine of a car has an intake valve and an exhaust valve, the intake valve is an inlet for fresh air and the exhaust valve is the outlet for the exhaust gases after the engine has been burned. While the intake valve of the engine is driven by the intake camshaft, the exhaust valve of the engine is driven by the exhaust camshaft, so this design is called a dual overhead camshaft.
Generally speaking, the top valve does not appear to pull the cylinder phenomenon, the general reason for this problem is that there are impurities in the oil, or there are impurities of metal in the place where the oil is stored, which are not filtered out, so the metal impurities enter the cylinder and produce scratches. And just like that, the piston ring will appear after running for a period of time, burning oil, machine running powerless and other related situations.
The front end of the intake camshaft will be equipped with a timing sprocket that is driven by a crankshaft wheel using a timing chain. A gasoline engine has four strokes, intake, compression, work and exhaust, which is a working cycle. Generally, if the engine top valve is serious, the engine will not start, if the top valve is not too serious, it can still start, but because the vehicle can not accelerate, the engine shaking will be serious.
