Low Engine Oil Pressure
Low engine oil pressure indicates insufficient oil supply in the main oil passage, or severe leakage in the oil circuit after the main oil passage. This is a common fault in lubrication systems (including: circulating lubrication systems, centralized lubrication systems, etc.), mainly due to the following reasons:
1. Insufficient oil in the engine oil pan. Check and add sufficient oil.
2. The oil filter is severely clogged, increasing suction resistance and reducing oil intake. The suction pipe connection is not tightened. Clean the oil filter and check and tighten the connections.
3. Low oil viscosity. Use suitable engine oil.
4. The oil pump is severely worn (a basic type of component failure), resulting in low oil pressure and insufficient oil output. Replace all oil pump parts.
5. The pressure limiting valve opening pressure is too low, causing excessive and premature oil return, leading to a drop in main oil passage pressure. In lubrication systems with a return valve on the main oil passage, low pressure or damage to the return valve may cause a drop in oil passage pressure.
6. If the oil filter in series with the main oil passage is blocked, and the safety valve opening pressure is too high, the internal leakage of the oil pump increases, reducing the oil volume in the main oil passage and lowering the oil pressure.
7. Excessive bearing clearance, oil leakage in the oil passage. The oil passages at both ends of the connecting rod journal are blocked or improperly installed.
8. The centrifugal fine filter rotor is severely contaminated with oil, or the rotor spray holes are worn, causing too much oil to enter the fine filter, and the amount of oil entering the oil passage is relatively reduced.
9. Wear of the crankshaft front end sleeve ring will cause a drop in oil pressure.
High Engine Oil Pressure
1. The oil holes leading from the main oil passage to the bearings are blocked by debris.
2. The return valve or pressure limiting valve spring tension is too high, or the ball valve is stuck for some reason, or the oil drain passage is blocked.
3. The oil temperature is too low, and the viscosity is too high.
4. The oil pressure gauge is malfunctioning.
High Engine Oil Temperature
I. 1. Prolonged operation under heavy load; the load should be reduced.
2. Partial blockage of the radiator.
3. Poor sealing performance of the cylinder and piston, allowing high-temperature gas to leak into the crankcase, heating the engine oil in the oil pan.
4. The oil level in the oil pan is too high, causing the crankshaft to violently agitate the engine oil, or the oil level in the oil pan is insufficient, resulting in insufficient oil pumping and reduced cooling effect of the engine oil circulation.
5. In lubrication systems with oil coolers, if the changeover switch is not tight or the oil flow in the radiator is obstructed, it will affect the cooling effect of the engine oil.
6. The oil temperature gauge is malfunctioning.
Engine oil temperature is too low
1. Insufficient preheating after engine start-up.
2. The oil temperature gauge is damaged.
Excessive engine oil consumption
1. Oil leakage due to damaged pipe joints or gaskets.
2. The piston rings are stuck and not performing their oil scraping function.
3. Wear of the piston rings and ring grooves, pumping oil into the combustion chamber.
