Compared with the gasoline engine, diesel engine abnormal sound diagnosis is more difficult to grasp, this is decided by the structure characteristics and working characteristics of the diesel engine, such as compression ratio, thermal load, work is relatively rough, big noise, broken oil cannot instantly, and even some diesel oil at the opening of the position of the people not easy to close, to the diagnosis of abnormal noise also brings inconvenience. However, the abnormal sound of the diesel engine has its specific rules, as long as the analysis and comparison, look at the phenomenon of grasping the essence, it is possible to find out its regularity.
Piston ring ring
Baotou beiben heavy truck parts piston ring percussion sound is blunt and dumb “pops” sound. The change of sound is characterized by the increase of the speed and the increase of the sound.
The reason
Piston ring fracture.
The piston ring groove carbon ring end gap too much or too small. When the temperature rises without expansion, the piston ring stuck in the ring slot or cylinder.
The Baotou beiben heavy truck parts piston ring and ring groove wear too much, backlash, backlash and end gap is too large.
The cylinder wear after the formation of the shoulder in the cylinder mouth, if the repair is not standardized, the piston moves up the piston ring and the convex shoulder touching, abnormal sound.
The diagnosis and treatment methods
The engine is running, open the machine cover observation with oil smoke, then gradually cut off oil cylinder, if it is found that the smoke reduced or disappeared, the sound disappears, then that is Baotou beiben heavy truck parts piston ring groove wear too much, or piston ring fault, should be timely maintenance.
If off the oil test sound did not change, but with the screwdriver head conflict site, there is a clear sense of vibration, is the piston ring cylinder wear a collision of the shoulder and the sound. This should be re – cylinder, so as to avoid the piston ring fracture.
In the hot check, can inject a small amount of oil, from the fuel injector inlet turning crankshaft, and then replace the injector test machine, a short period of time if the sound is weakened or disappeared, the piston ring and cylinder wall sealing side. If the injection of oil, the oil is still from the mouth of smoke or even more, can be diagnosed as piston ring or piston ring loses its elasticity in the ring groove, which should be maintained, thoroughly remove coke.