Is it normal for the waste gas valve pipe to have slight oil? What is the reason for the oil leakage of waste gas valve?

It is abnormal that there is a small amount of oil in the waste gas valve pipe. The reason for the oil leakage of the waste gas valve may be the serious wear between the valve guide and the valve stem, which leads to the excessive clearance and the downward flow of oil. The solution is to find the damaged place and replace it. It is also possible that there is something wrong with the waste gas valve, which is generally installed near the valve cover, with one side connected to the throttle inlet hose and the other side connected to the valve cover. When it has problems, it will lose the function of oil-gas separation, and at the same time, it will suck in engine oil, so that the waste gas valve pipe has engine oil. In this case, the oil-gas separator can be replaced. Waste gas valve, also known as oil-gas separator, is used to separate engine oil from the exhaust gas discharged from crankcase, so as to reduce the discharge of engine oil from the breathing port of crankcase. If it fails, it may also cause the turbocharger to fail to work normally and make the car unable to accelerate.