What are the causes of low oil pressure in diesel engines?
1 Answers
Low oil pressure in diesel engines may be caused by insufficient oil volume, excessively high engine temperature, malfunction of the oil bypass valve, or a clogged oil filter. Low oil pressure can lead to severe engine wear and significantly reduce its service life. Below are detailed explanations: Insufficient oil volume: If the oil volume is insufficient, the oil pump's output will decrease or fail to pump oil due to air ingress, resulting in reduced oil pressure. This can cause increased wear on the crankshaft and bearings, as well as the cylinder liners and pistons due to inadequate lubrication. Excessively high engine temperature: If the engine cooling system has excessive scale buildup, poor heat dissipation, prolonged overload operation, or delayed fuel injection timing, the engine may overheat. This accelerates oil aging, degradation, and thinning, causing leakage through various clearances and a drop in pressure. Oil bypass valve malfunction: The oil bypass valve maintains normal oil pressure in the main oil passage. If its pressure-regulating spring weakens or is improperly adjusted, or if the valve seat and ball bearing surfaces wear out or become stuck and fail to close tightly, the oil pressure will decrease. Clogged oil filter: When the oil filter is clogged and cannot allow oil flow, the bypass valve located at its base opens, allowing oil to bypass the filter and enter the main oil passage directly. If the bypass valve's opening pressure is set too high, it may not open promptly when the filter is clogged. This can cause the oil pump pressure to rise, increase internal leakage, and result in a drop in oil pressure.
