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Why does the oil pressure of the diesel generator set fluctuate?

April 20, 2022
The oil pressure of diesel generator set is generally maintained within the pressure range of 150 ~ 350kPa. If the pressure value indicated by the oil pressure gauge is less than 98kPa, it can be considered that the oil pressure is too low, and it should be stopped immediately for inspection.
Check the quality and quantity of the engine oil of the diesel generator set. For diesel engines with too low oil pressure, generally check whether the oil quantity meets the requirements. If the amount of oil is too small, the fault is obvious. If the amount of oil meets the requirements or is too much, you should carefully observe whether the oil has diesel oil or moisture. If the oil is mixed with diesel, the oil will become thinner and the viscosity will drop, resulting in too low oil pressure. The reasons for the high and low oil pressure of diesel generator sets are as follows:
1. Insufficient oil volume in the warm bottom case When the diesel engine is just started, the oil pressure is normal, and it will drop below 0.1MPa after 1 min. The pressure will be slightly higher during medium and high speed operation, but with the increase of operating time, the oil temperature increases, the oil pressure becomes lower. At this time, the oil dipstick should be taken out to check whether the oil is sufficient. If it is insufficient, add the oil of the same brand and the same manufacturer according to the standard.
2. The oil is too dirty and sticky, blocking the oil suction pan. When the diesel engine runs at low speed with small throttle, the main oil passage can still maintain a certain pressure due to the small amount of oil absorbed by the oil pump, so the oil pressure is normal. However, when the engine is running at high speed, the amount of oil absorbed by the oil pump will be obvious due to the excessive resistance of the oil suction plate. If it is reduced, the oil supply of the main oil passage will be insufficient, and the oil pressure will drop instead. In this case, the oil suction plate should be cleaned, the oil passage should be cleaned, and new oil should be replaced.
3. The spring of the pressure limiting valve is deformed or broken, and the opening and closing are ineffective. When the diesel engine runs with a small throttle, the valve is closed, and the main oil passage can maintain a certain pressure. When the throttle is running, the fuel supply increases sharply, which will cause the valve to open suddenly and the oil pressure to drop. , the valve may not be able to return in time, it is more difficult to maintain the proper pressure in the main oil passage than when the throttle is running, and the oil pressure fluctuates. The pressure limiting valve should be repaired according to technical requirements.