What Causes White Smoke from the Engine Exhaust Pipe?
1 Answers
White smoke from a car engine is caused by low temperatures. During engine operation, the exhaust gases expelled encounter the cold external environment, leading to instant condensation. The resulting water vapor produces a large amount of fog-like white smoke. There are many reasons for white smoke emission, mainly including the following aspects: 1) The engine temperature is too low. Some diesel fuel does not burn completely and turns into oil vapor, which is expelled with the exhaust gases, resulting in white smoke. 2) Water in the fuel system. If there is water in the fuel or combustion chamber, it is heated by the combustion heat in the cylinder and turns into steam, which is expelled from the exhaust pipe as white smoke. 3) Delayed fuel injection. Due to late injection timing, the cylinder temperature has already dropped when the fuel is injected, causing some diesel to remain unburned and turn into oil vapor, leading to white smoke. 4) Poor fuel injector atomization. Inadequate atomization prevents complete combustion of diesel, which then mixes with the high-temperature exhaust gases from normally operating cylinders in the exhaust pipe, resulting in white smoke. 5) Low cylinder pressure. Some diesel fuel turns into oil vapor without burning, thus causing white smoke from the exhaust pipe.
