White smoke, blue smoke and black smoke from excavators are common faults of excavators. This article will outline the causes of smoke from excavators for reference only.
1. White smoke
1) Most of the white smoke is caused by water in the cylinder. Please check whether there is water in the diesel. Generally, the white smoke time after startup is very short, and there is no problem with the engine.
2) If the excavator starts emitting white smoke, the engine oil is not reduced, and the excavator is unable to work, it indicates that the engine cylinder mattress is damaged.
3) Poor atomization of fuel injector and low cylinder pressure are also one of the reasons for white smoke from the engine. Check the fuel injector.
2. Blue smoke
1) Blue smoke appears when the excavator is stopped and just started
It is normal for the excavator to emit blue smoke when it is shut down and disappear after starting for a period of time, because a small part of oil will invade the engine combustion chamber after shutdown.
2) Continuous blue smoke after startup
If the diesel filter element is blocked, check whether the oil model is correct.
Engine piston ring and valve oil seal are worn, resulting in oil in inlet or exhaust pipe, resulting in blue smoke of excavator.
The matching clearance between piston and cylinder liner is too large, resulting in blue smoke.
Blue smoke is a major feature of engine oil burning when engine oil is mixed with diesel.
3. Black smoke
Black smoke is the external manifestation of insufficient combustion of fuel in the cylinder. We should start from three aspects:
1) Insufficient air intake. Check whether the intake valve clearance is within a reasonable range. Improper valve clearance will cause insufficient intake pressure and quantity. Check whether the air filter element is blocked. The supercharger is damaged, resulting in insufficient intake pressure.
2) Poor diesel quality, worn diesel pump and fuel injectors.
3) The injector is worn and injected too much, resulting in insufficient combustion. Please ask the service personnel to conduct the engine cylinder breaking test to check whether it is caused by the wear of the fuel injectors.
