Crude refers to the engine in the combustion process, the piston at TDC near the burning speed large amount of combustion phase of diesel, which result in the high rate of pressure rise when the engine works appear crisp metal percussion sound, and chattering, rapid acceleration of unrhythmic knock intensified, with a row of black smoke, high speed the percussion sound diminished or disappeared. This phenomenon will greatly affect the engine life.
The reason
Diesel oil quality is poor, sixteen alkane value is too low.
The fuel injection advance angle is too large.
The Baotou Benz accessories injector sealing, fuel leakage, atomization adverse.
The cylinder oil are individual cylinder oil supply amount is too large.
The insufficient air intake.
The diagnosis and treatment methods
If the percussion sound is not uniform, sometimes accompanied by shaking phenomenon, indicating that the individual cylinder. In a hot car, available single cylinder oil reduction method, after the cold starting temperature method to find the available work side cylinder. For example, in the initial stage of starting a cylinder exhaust manifold heater, that the amount of oil of the cylinder; on the other hand, may be the cylinder oil supply amount of small or bad injector.
Remove the fault injector, check and confirm the injector failure, can also be used to replace the standard injector injector test, if the sound disappears, indicating that the fault on the injector.
If the change of standard injector after the cylinder knocking had not disappeared, it may be due to the large amount of available fuel, oil reduction method to judge the check. Which is slightly loose the lime cylinder injector inlet pipe joints, so that a small amount of diesel spray in cylinder, reducing the fuel into the cylinder. If the use of this method after the elimination of percussion sound can be confirmed that the cylinder oil supply is too large, it is necessary to check the fuel injection pump uniformity.
If the knocking sound is relatively uniform, that is close to the working condition of each cylinder, the fault reason and diesel quality, inlet condition, injection timing and so on. Check the intake status. Check and clean up Baotou North Benz parts filter. If the sound is weakened or disappeared, it is indicated that the engine exhaust black smoke and percussion. If the noise and exhaust smoke has no obvious change, that the air cleaner is good, should check the air intake hose has a concave or delamination block.
If the intake is normal, may be not appropriate or not grade diesel fuel injection timing, the first should be appropriate to reduce the fuel supply advance angle, exhaust and noise observation of Baotou Benz engine accessories have changed. If reducing the fuel supply advance angle, normal exhaust smoke, knocking away, then that is not caused by the fuel injection timing. If the fault has not been eliminated, it may be caused by incorrect diesel grades.