Failure analysis and solution if diesel genset engine exhaust smoke is not normal

newsdh (1)

Normal operation of diesel engine with load, exhaust smoke color is light gray commonly, when the load is a little heavy, may be to dark grey. Here exhaust smoke color abnormal refers toexhaust smoke is black or exhaust smoke is white or exhaust smoke is blue.

1、Smoke black indicate the combustion of diesel fuel in the combustion chamber is not sufficient.

Failure Analysis:

〈1〉engine is over load

〈2〉oil drip of fuel injector, poor atomization

〈3〉Fuel supply time early


〈1〉Adjust the load, make in rated range

〈2〉When diesel engine on idle running, loosen the high pressure injector tubing connector one by one in order to stop the fuel injection of injector, watching the color of the exhaust: speed of engine decreases significantly after injection stopped if there is no fault in the fuel injector. In case the injector is failure, the speed of engine changes very little, exhaust smoke won’t be black after injection stopped. Should to check and adjust the injector.

〈3〉According to the specifications, check the fuel supply advance Angle

Maintenance experience:

Requirements for the injector: must have certain injection pressure, a certain range and spray cone Angle, spray is good. Fuel injection can quickly stop the end of oil, no oil leakage, oil impregnate phenomenon.

smoke white indicate the diesel oil drops in the combustion chamber is not burning

Failure Analysis:

〈1〉Cylinder pad damage;

〈2〉oil delivery time is too late

〈3〉Water in the fuel oil.


change new cylinder pad

〈2〉According to the specifications, check the fuel supply advance Angle

〈3〉Install fuel oil and water separator

Maintenance experience:

In order to have good sealing, cylinder gasket must be put between cylinder head and cylinder block. Tighten the cylinder head on the cylinder block by bolt and should have a certain order, as the central symmetrical around the order to the extension by several times, and finally a torque wrench to tighten torque value as stipulated in the manual.. Remove the bolts and vice.

3、smoking blue indicate that the oil string into the combustion chamber.

Failure Analysis:

〈1〉The oil level of oil sump is too high

〈2〉Oil ring stuck inside a ring groove or rupture

〈3〉Connecting rod bearing and connecting rod journal clearance is too large


〈1〉Keep the oil sump oil in static full scale, and drop some engine oil timely;

〈2〉Clean up the piston ring groove carbon deposition, change the oil ring;

〈3〉Remove the oil pan, connecting rod bolts removed, intuitive whether there were signs of burning bearing in surface, if yes, replace the connecting rod bearing shell.

newsdh (2)

Post time: Apr-28-2021