If the excavator makes abnormal noise, it is uncertain and can not be operated forcibly, so it can only be stopped for inspection. Here, taking the abnormal noise of Hitachi zx240-3 engine as an example, how to troubleshoot and solve the problem is described.
1. Fault analysis
During normal operation of excavator engine, there is regular exhaust sound and slight noise. There is a fit tolerance within the normal range between internal parts. If the fit tolerance exceeds the normal range due to excessive wear, there will be abnormal noise. In case of such faults, first determine the location where the abnormal sound is emitted and the type of sound.
The abnormal noise of the engine mainly includes piston knocking, timing gear wear, piston pin, bearing, valve, exhaust pipeline, turbocharger, etc.
2. Troubleshooting
1) After starting the equipment, due to the oil pressure alarm, the maintenance personnel first checked the excavator air filter element, oil quantity and oil quality, and found that the oil had sundries and deterioration. The operator was consulted and reported that the engine oil previously purchased was recommended by a friend, not from a regular store.
2) According to the observation and confirmation of the maintenance personnel, the position where the abnormal noise occurs is the position of the turbocharger.
3) After disassembling and inspecting the turbocharger, it is found that the axial clearance of the turbocharger is 1.5mm, the longitudinal clearance is 1mm, and there is crimping at the impeller edge of the turbocharger. It is determined that the clearance is too large due to the wear of the axle of the turbocharger, resulting in abnormal noise.
3. Fault cause and treatment
The purchased inferior engine oil leads to low engine oil pressure and poor engine oil lubrication effect, resulting in wear and abnormal noise of turbocharger axle.
Replace with genuine engine oil that meets the equipment requirements. After replacing the worn turbocharger, the abnormal sound disappears and the equipment returns to normal.
It should be noted that in order to prolong the service life of the turbocharger, do not increase the engine speed immediately after the engine is started, and be sure to idle for a few minutes before flameout.
The function of the turbocharger is related to the power of the engine. When the turbocharger is worn and makes abnormal noise, it must be shut down immediately for maintenance and troubleshooting. At ordinary times, we should pay attention to the maintenance of the supercharger. We must buy genuine engine oil to meet the equipment requirements, so as to avoid equipment failure due to inadequate maintenance.
