Abnormal sound of diesel engine
Introduction
Diesel engines are widely used in automobiles, ships, generators, and agricultural machinery. Diesel engines have the advantages of large power, reliable operation, economical fuel consumption, and so on. However, when diesel engines are running, abnormal sounds will occur due to various faults in the engine. If the abnormal sound is not treated in time, it will not only affect the normal operation of the diesel engine but also cause greater economic losses. Therefore, the abnormal sound in the diesel engine needs to be diagnosed and eliminated in time. This paper mainly introduces the diagnosis and elimination of abnormal sounds in diesel engines.
Diagnosis of abnormal sound in diesel engine
1. According to the volume and characteristics of abnormal sound
When diesel engines run abnormally and make abnormal sounds, it is generally possible to determine the cause of the fault from the volume and characteristics of the abnormal sound. For example, when a diesel engine makes a loud and dense sound, it may be caused by high-speed burning; when a diesel engine makes a loud and uninterrupted sound, it may be caused by ablation; when a diesel engine makes a noise, it may be caused by the explosion of the injector; when a diesel engine produces a periodic tick, it may be caused by the valve failure; when a deep and dull sound is heard, it may be caused by something wrong with the bearings.
2. According to the instrument
In addition to judging the cause of the fault by the volume and characteristics of the abnormal sound, the instrument can also be used to diagnose diesel engine faults. Before diagnosing with an instrument, it is necessary to perform preoperational inspection on the diesel engine, including checking the fuel pipe, oil supply pipe, and battery. If the situation is normal, the instrument can be used to diagnose the problem with the diesel engine. Generally, by inspecting the pressure value in the cylinder and the data related to the engine speed according to the instrument, it can be judged whether the engine output power is normal, the quality of the fuel consumed, the working condition of the pistons, the load status of the connecting rod, and other conditions.
Elimination of abnormal sound in diesel engine
1. Low speed and burning
If the diesel engine runs at low speed and makes dense sound, first check the fuel injectors for ablation and injector leaking pressure. The fuel injector will be replaced if found; then the comprehensive performance of the diesel engine should be checked for abnormality. If the comprehensive performance of the diesel engine is abnormal, the cylinder head should be removed for cleaning and inspection. If the diesel engine is abnormal, it should be adjusted in time and the cylinder head replaced if necessary.
2. Abnormal exhaust noise
If the diesel engine exhaust produces abnormal sound and black smoke, first check its fuel injection system, such as the pressure of the fuel injection pipe, the temperature of the nozzle, the pressure of the fuel tank, and so on. After confirming that the fuel injection system of the diesel engine is normal, the ratio of the injection amount should be adjusted. If the diesel engine still has abnormal sound and black smoke, it may be caused by the failure of the air injection system of the diesel engine. In this case, it is necessary to adjust the intake manifold pressure and clean the intake valve. In addition, if it has been found that the diesel engine is abnormal due to air leakage from the cylinder head gasket, the cylinder head gasket shall be replaced.
3. Valve failure
If the diesel engine produces periodic tic, it may be a sign of valve failure. In order to eliminate this kind of failure, it is necessary to check the valve for jamming and gap, and then adjust its clearance. If after adjusting the clearance of the valve still can not normal operation, should consider replacing the valve or valve seat.
Conclusion
The abnormal sound in the diesel engine not only affects the normal operation of the diesel engine but also causes great economic losses. Therefore, it is necessary to diagnose and eliminate the abnormal sound in the diesel engine in time. In the diagnosis of abnormal sound of diesel engines, the volume and characteristics of the abnormal sound should be distinguished first, and then the instrument can be used to further diagnose the problem. In the process of eliminating abnormal sounds, the fuel injection system and air injection system should be checked and adjusted, and the cylinder head gasket should be replaced if necessary.
