How to deal with valve noise?

First of all, the valve ring refers to the rhythmic knocking sound produced when the engine is running. The greater the engine speed, the larger the valve ring. There are several ways to deal with it. First of all, you can check whether the clearance of the valve is too large and adjust it appropriately. If it is caused by the wear of camshaft and valve foot, it is necessary to replace camshaft or valve foot; It is also possible that the viscosity of the oil is too high, and it is necessary to replace the appropriate oil.