When the cylinder head gasket is damaged or not tightly sealed, the engine cannot work normally and must be replaced immediately. The specific steps are as follows:
1. Remove the valve cover and gasket.
2. Remove the valve rocker arm assembly and take out the valve push rod.
3. Loosen and remove the cylinder head bolts in three steps in a symmetrical sequence from both ends to the middle, and remove the cylinder head and gasket.
4. Remove the drilling objects on the joint surface of the cylinder block and cylinder head.
5. Turn the smooth side or the wider side of the new cylinder head gasket toward the cylinder block. The opposite is true for cast iron cylinder blocks and aluminum cylinder heads.
6. When installing the cylinder head, first use the positioning bolts to position the cylinder head. After the other cylinder head bolts are tightened by hand, remove the positioning bolts and install the cylinder head bolts.
7. Use a torque wrench to gradually tighten to the standard torque in 2-3 times in the reverse order of disassembly.
8. Install the valve push rod and valve rocker arm assembly in the original position. After checking and adjusting the valve clearance, install the gasket and valve cover.