Automobile exhaust pipe black oil

When gasoline is completely burned, it will produce water and carbon dioxide. Water is steam at high temperature, and steam is colorless and transparent at high temperature. However, when the temperature is lower than 100℃, steam will condense into water, carbon will be deposited on the exhaust pipe, and the water will turn black with the exhaust gas.

This is an abnormal phenomenon. The main component of "black oil" is engine oil. Because the wear between the cylinder and the piston is too great, the seal becomes worse. The engine oil enters the cylinder cavity from bottom to top, and then is discharged with the exhaust gas. Because of the high density of engine oil, it must be deposited at the exhaust pipe. You'd better look in the garage. Minor ailments should be treated as soon as possible.