Cause analysis of abnormal exhaust of diesel engine

Cause analysis of abnormal exhaust of diesel engine

Diesel engine exhaust black smoke fault causes

The black smoke in the exhaust is mainly carbon particles of incomplete combustion of fuel. Therefore, the excessive supply of fuel in the fuel supply system, the reduction of air intake system, the poor sealing of the cylinder block, cylinder head and piston combustion chamber, the poor injection quality of the injector and other factors will make the fuel combustion is not complete, thus making the exhaust black smoke. Exhaust black smoke mainly has the following reasons:

1. The oil supply of high pressure oil pump is too large or the oil supply of each cylinder is uneven

2. The valve seal is not strict, resulting in air leakage, low cylinder compression pressure

3. The air filter inlet is blocked and the air intake resistance is large, which makes the air intake insufficient

4. Cylinder liner, piston, piston ring serious wear

5. The fuel injector is not working properly

6. The engine is overloaded

7. The fuel advance Angle of the injection pump is too small, and the combustion process is moved to the exhaust process

8. Gasoline electric injection system control failure

The black smoke engine can be checked and eliminated by high-pressure oil pump adjustment, injector injection test inspection, cylinder compression pressure measurement, inlet cleaning, adjustment of fuel supply advance Angle, fault diagnosis of gasoline electric injection system and other work.

Fault cause of exhaust white smoke of diesel engine

The white smoke in the exhaust is mainly the fuel particles or water vapor that is not fully atomized and burned. Therefore, all the fuel can not be atomized or water enters the cylinder and the exhaust will emit white smoke. There are mainly the following reasons for induction:

1. The temperature is low and the cylinder pressure is insufficient, the fuel atomization is not good, especially the exhaust smoke at the early stage of cold starting

2. Cylinder pad damage, cooling water into the cylinder

3. The cylinder is cracked and the cooling water seeps into the cylinder

4. The water content in the fuel is large

When cold starting, the exhaust emits white smoke, and the white smoke disappears after the engine is warm. If the vehicle still emits white smoke during normal operation, it is a fault. It should be checked and analyzed by observing whether the cooling water in the water tank is not consumed normally, whether the cylinders work normally, and whether the oil and water separator has too much water, to eliminate the fault parts

Blue smoke from diesel engine exhaust

The blue smoke in the exhaust is mainly the result of excessive oil injection into the combustion chamber. Therefore, anything that causes oil to jump into the combustion chamber will cause the exhaust to emit blue smoke. There are mainly the following reasons for induction:

1. Piston ring is broken

2. The oil hole on the oil ring is blocked by carbon deposition and loses the oil scraping function

3. The piston ring openings turned together, causing oil to run through the piston ring openings

4. Piston ring wear is serious or by carbon accumulation stuck in the ring groove, loss of sealing effect

5. Install the air ring in reverse direction, scrape the oil into the cylinder and burn it off

6. The spring of the piston ring is not enough and the quality is not up to standard

7. Improper assembly or aging of the oil seal of the valve conduit, loss of sealing effect

8. Severe wear of piston and cylinder

9. Too much oil is added, so that the oil splashes too much, and the oil ring has no time to scrape the excess oil on the cylinder wall

Exhaust blue smoke inevitably accompanied by increased oil consumption, some drivers called "burning oil". The oil and fuel consumption ratio is generally 0.5% ~ 0. 8%, oil consumption

When this value is exceeded, blue smoke will be produced in the exhaust. Blue smoke engine failure, generally through the engine disintegration, inspection, to find out the cause and determine the troubleshooting program. If the smoke exhaust is blue in the cooler state, but the oil consumption is normal, it is related to the fuel, and it is considered normal.

Engine smoke exhaust should generally be checked in the engine warm state, through the engine low speed, medium speed, high speed and acceleration process of the change of smoke exhaust color analysis.