Is It Normal to Have Engine Oil in the Exhaust Pipe?

[Justin]

Having engine oil in the exhaust pipe is not normal and requires immediate repair at a 4S shop. This phenomenon is most likely caused by a malfunction of the car's exhaust valve, which needs to be replaced promptly. Otherwise, it will affect the normal emission of the car's exhaust gases. The exhaust valve, also known as an oil separator or pressure control valve, is installed between the compressor outlet and the condenser inlet. It serves as a tool to improve the heat transfer efficiency of the condenser and evaporator by separating the oil. The working principle of the exhaust valve is as follows: after the high-pressure gas from the compressor enters the exhaust valve, it passes through the guide vanes inside the valve. The centrifugal force and gravity separate the lubricating oil from the gas, allowing the lubricating oil to be periodically discharged and returned to the compressor's crankcase.