Teach you to solve the machine oil pressure warning light problem      

When an excavator works, the oil suddenly appears on the dashboard, and the driver stops to check immediately. What causes the engine oil pressure to be abnormal during the engine operation? Today, with small series together to see the detailed analysis of the reasons.

The lubrication system of diesel engine is mainly composed of oil pan, oil pump, oil filter, radiator, main oil path, oil separation path, oil pressure alarm sensor, oil temperature alarm sensor, pressure limiting valve and bypass valve. The oil pressure is too low mainly for the following reasons:

1, insufficient oil

If the amount of oil is insufficient, the oil pump will reduce the amount of oil, or because of the air into the pump does not oil, so that the oil pressure drops, crankshaft and bearings, cylinder and piston will be due to poor lubrication and wear. Therefore, the oil level in the oil pan should be checked before the daily work to ensure the normal oil level, and the same type of engine oil produced by the same manufacturer should be added when not enough.

2, the oil pump does not turn

If the flat key of the drive gear and drive shaft of the oil pump is damaged or fallen off; the filter damage causes the oil pump to absorb foreign matter and the gear is jammed, which will cause the oil pump to stop and the oil pressure drops to zero. The damaged flat key or strainer shall be replaced at this time.

3, oil pump wear

The clearance between the shaft and bushing of the oil pump, the clearance between the gear end face and the cover of the pump, the clearance of the tooth side or the radial clearance due to excessive wear will lead to the decrease of the pump oil and the decrease of the oil pressure. You should replace the worn parts, grinding pump cover plane, the gap and the gear end back to the standard range.

4, the engine temperature is too high

If the engine cooling system is too thick, poor heat dissipation, long time overload operation or fuel injection pump time is too late, will overheat the engine, accelerate the aging of the oil, deterioration, thinning, leakage from the coordination gap, pressure reduction. The scale should be removed, the oil supply time should be adjusted, and the engine should be operated within the rated load.

5. Filter clogging

Under normal conditions, the engine oil pressure should be higher at the throttle than at the small throttle, but sometimes it will be abnormal. If the oil is too dirty or too viscous, it is easy to block the filter. When the engine throttle at low speed, the machine oil pump suction amount is not large, the main oil channel is able to set up a certain pressure, so the oil pressure is normal; but when the throttle is running at high speed, the amount of oil pump will set the filter resistance and significantly reduced, and because the main oil supply shortage in the value decreased the oil pressure gauge. Suction filter should be cleaned or oil replaced.

6, bypass valve damage

In order to maintain the normal oil pressure of the main oil duct with bypass valve, if the pressure regulating spring is softened or improperly adjusted, the valve seat and the steel ball face wear or stuck, and when the closure is not strict, the oil return increases, the pressure of the main oil duct will drop. At this point, you should remove the bypass valve for inspection, and finally adjust the pressure to the normal range.

7, oil radiator leakage

Outside leakage will pollute the engine surface, pressure drop; internal leakage makes the oil into the water tank, cooling system cooling effect becomes worse, engine overheating, oil thinning, pressure drop. Remove the radiator, repair or replace, restore its function.

8. The setting pressure of the pressure limiting valve is too low

In the lubrication system, the oil from the oil pump must ensure proper pressure before reaching the lubrication parts of the engine. If the setting pressure of the pressure limiting valve is too low, the pressure regulating spring becomes soft or the seal surface leaks, the setting pressure will be too low. The pressure limiting valve should be adjusted so as to make the pressure return to normal.

9, improper oil brand

Different engines need to add different grades of engine oil, the same type of engine in different seasons should also choose different grades of engine oil. If the selected oil is not suitable or inferior oil, the engine will be running due to viscosity is too low to increase leakage, pressure reduction. The engine oil should be correctly and reasonably adapted to different models or seasons.

10. Pressure sensor failure or oil path blockage

If the pressure sensor fails or the main oil path is blocked to the pressure sensor, and the oil flow is not smooth, the oil pressure will drop. Can do the following inspection: engine idle operation, loosen the oil pipe connector, observe the oil flow situation, judge the fault location, change the pressure sensor or cleaning oil duct.

11, oil filter clogging

When the oil filter is clogged and cannot be circulated, the bypass valve on its base is opened, and the oil is directly entered into the main oil duct without filtering. If the bypass valve opening pressure setting is too high, when the oil filter is blocked, it can not be opened in time, the pressure of the oil pump will rise, the leakage will increase, the oil supply to the main oil channel decreases, the oil pressure will drop. The cleanliness of the oil filter should be ensured; the opening pressure of the bypass valve should be adjusted properly; the damaged components or mating surfaces should be replaced or repaired in time to restore their normal working performance.

12. The clearance between main bearing and connecting rod bearing increases

When the engine is used for a long time, the clearance between the main crankshaft and the connecting rod bearing increases gradually, the leakage increases, and the oil pressure drops. The pressure decreases by 0.01mm when the clearance is increased by 0.01MPa. At this point, the crankshaft can be repaired, and new connecting rod bearings and main bearings are selected to restore the clearance.

By excluding this fault, indicating that mechanical failure is not terrible, as long as the understanding of the working principle of the system, careful analysis, you can certainly troubleshoot, but do not blindly disassemble, otherwise, it will work twice with half the effort, or even damage the work of the normal components.