If the engine oil level is insufficient, the oil pump’s delivery volume will decrease or, due to air entrainment, the pump may fail to deliver oil altogether, resulting in a drop in oil pressure. Consequently, the crankshaft and bearings, as well as the cylinder liner and pistons, will experience accelerated wear due to inadequate lubrication. Therefore, the oil level in the oil pan should be checked before each day’s operation to ensure it is within the normal range; if the level is low, add engine oil of the same grade and from the same manufacturer.

Excessive scale buildup in the engine cooling system, poor heat dissipation, prolonged operation under overload, or excessively late fuel injection timing can all lead to overheating of the engine, accelerating the aging, degradation, and thinning of the engine oil, resulting in leakage through clearance gaps, reduced oil pressure, and other issues. To address these problems, it is necessary to remove scale, adjust the fuel injection timing, and ensure that the engine operates within its rated load limits.

External leaks contaminate the engine surface and cause pressure loss, while internal leaks allow oil to enter the radiator, degrading the cooling system’s heat dissipation and leading to engine overheating. This results in oil thinning and further pressure drop. Remove the radiator, repair or replace it, and restore its functionality.

Different engines require different grades of engine oil, and even the same engine model should use different grades depending on the season. If the wrong grade or a low-quality oil is used, the oil’s viscosity may be too low during operation, leading to increased leakage and reduced pressure. Therefore, it is essential to select the appropriate oil—both in terms of grade and formulation—to match the specific engine type and seasonal conditions.

By systematically troubleshooting these issues, it becomes clear that mechanical failures are not something to be feared. As long as you understand the system’s operating principles and conduct a careful analysis, you can invariably resolve the problem. However, avoid disassembling components indiscriminately; otherwise, you may end up achieving only half the results with twice the effort, or even damage perfectly functional parts.