Excavator sees smoke exhaust diagnosis fault

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There are three types of fault diagnosis for excavator smoke:


1.White smoke failure


2.Smoky failure


3. Blue smoke failure


1. White smoke failure:

The main reason for the white smoke of the excavator is that the temperature in the cylinder is low when the diesel engine is just started or in the cold state, and the oil and gas are evaporated. However, if the exhaust pipe is still emitting white smoke during the heat engine, then it can be preliminarily judged that the diesel engine is malfunctioning.

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The main reasons are as follows:

1. The cylinder liner is cracked or the cylinder pad is damaged, the cooling water enters the cylinder, causing the excavator to emit white smoke, and the excavator is weak. At this time, we can approach the exhaust pipe by hand. If the flue gas touches the hands with water droplets, it can be proved that water has entered the cylinder.


2, the fuel injection pump pressure is too low or the piston, cylinder liner and other serious wear and tear caused by insufficient compression force. If the excavator emits white smoke at first, and then emits black smoke when the temperature of the excavator becomes high, it means that the pressure of the excavator cylinder is insufficient.


3. The presence of water and air in the fuel can also cause the white smoke failure of the excavator, so it is necessary to frequently discharge the accumulated water to the oil-water separator.


4. Poor atomization of the injector, oil dripping, and white smoke from the excavator.


5. If the fuel supply advance angle is too small, the excavator will emit white smoke, at the same time, the acceleration is not flexible enough, and the work is weak.


2. Black smoke failure

The main reason for the black smoke of the excavator is that the fuel gas is mixed and the fuel is not completely burned. Diesel is injected into the combustion chamber. Unburned diesel is decomposed by high temperature to form carbon black, which is discharged along with the exhaust gas to form black smoke.

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The main reasons are as follows:

1. After the valve, piston ring and cylinder liner are worn, the compression pressure is insufficient, and the oil enters the combustion chamber, so that at the end of the compression stroke, the normal proportion of the mixed gas mixture is changed, so that the fuel is burned under anaerobic conditions and carbon deposits are generated. This eliminates black smoke.


2. The fuel injector has poor atomization and oil dripping phenomenon, so that the fuel cannot be fully mixed with the air and cannot be fully burned.


3. The combustion chamber is deformed or the quality is not up to standard. If the compression gap is too large or too small or the piston is installed incorrectly, it will affect the fuel-air mixing ratio and make the fuel unable to fully burn.


4. The fuel supply advance angle is too small, the fuel is injected too late, and some fuel is separated or discharged before it can be mixed with the air. The fuel discharged with the exhaust gas is decomposed by high temperature to form black smoke.


3. Blue smoke failure


The blue smoke from the excavator is very likely that the oil enters the cylinder, evaporates into blue oil and gas, and emits blue water vapor with the exhaust gas.

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The main reasons are as follows:

1. The air filter is blocked, the air intake is not smooth, or the oil level in the oil basin is too high so that there are more oil and less gas, and the fuel is not completely burned, causing the excavator to emit blue smoke.


2. Due to the excessive addition of engine oil in the oil pan, some lubricants may be mixed in the fuel.


3. The piston rings, pistons, and cylinder liners are worn, the gap between the pistons and cylinder liners is too large, or the piston ring chamfering direction is reversed during installation, which may cause the oil to enter the combustion chamber.


When excavating the excavator, pay attention to the color of the exhaust of the excavator to judge and analyze whether the diesel engine may be faulty, identify the problem as early as possible, and avoid greater losses.