1. Clogged oil passages: If the oil passages that supply oil to the valve train are clogged, the oil will not be able to reach the lifters, rocker arms, and other components on that side of the engine. This can cause the components to wear out prematurely and eventually fail.
2. Worn oil pump: If the oil pump is worn, it will not be able to generate enough pressure to circulate oil through the engine. This can also cause the oil to not reach the valve train on one side of the engine.
3. Defective oil pressure relief valve: If the oil pressure relief valve is defective, it may not be able to properly regulate the oil pressure in the engine. This can cause the oil pressure to be too high or too low, which can both damage the engine.
4. Incorrect oil viscosity: If the oil viscosity is too thick or too thin, it may not be able to properly circulate through the engine. This can also cause the oil to not reach the valve train on one side of the engine.
If you are experiencing this issue, it is important to have the engine inspected by a qualified mechanic to determine the cause and have it repaired as soon as possible.
