What are the causes of black smoke, white smoke and blue smoke from automobile exhaust pipe?

It shows that the engine mixture is too rich and leads to insufficient combustion. When the air filter is too dirty, the spark plug is broken, the ignition coil is faulty, etc. , will cause the engine to emit black smoke.

2, the exhaust pipe emit white smoke:

It shows that some gasoline does not burn because of poor atomization or dripping oil from the injector; There is water in gasoline; The cylinder head and cylinder liner have cracks invisible to the naked eye, and the cylinder gasket is damaged, so that water enters the cylinder; The machine temperature is too low. It can be solved by the following methods: cleaning or replacing the fuel injector and adjusting the injection pressure; Clear the water in the oil tank and oil circuit; Do not buy low-priced and inferior oil; Replace the cylinder gasket, cylinder liner and cylinder head.

3, blue smoke from the exhaust pipe:

It shows that the oil enters the combustion chamber to participate in combustion, the piston ring and cylinder liner are not completely run-in, and the oil enters through the gap; The piston ring is stuck in the groove, and the conical surface of the piston ring is installed backwards, losing the oil scraping function; The piston ring is excessively worn, and the oil runs into the combustion chamber from the opening gap; The oil level in the oil pan is too high; The valve and guide tube are worn and the gap is too large. It can be solved by the following methods: new cars or overhauled locomotives must be run-in in the engine according to regulations to make all parts mesh normally; See the assembly mark clearly and install the piston ring correctly; Replace qualified or enlarged piston rings; Find out the cause of the oil level rise in the oil pan and drain the excess oil in the oil pan; Reduce the amount of oil in the filter oil pan; Replace the valve guide.