German engine oil manufacturer
1, the oil pressure is always too low.
The oil pressure sensor is usually installed in the main oil gallery. If the oil pressure gauge and oil pressure sensor are normal, but the pressure indicated by the oil pressure gauge is too low, the possible causes of the failure can be analyzed according to the composition of the lubrication system and oil circuit. If the oil pressure sensor divides the oil passage into two parts in the direction of oil flow, the reasons for the low oil pressure can be divided into two aspects: first, the oil passage in front of the oil pressure sensor is not smooth (such as the filter is blocked) or the oil supply is insufficient (such as the oil quantity is insufficient); Second, the oil circuit behind the oil pressure sensor leaks oil too quickly (such as the crankshaft bearing clearance is too large). Although the lubricating system composition and oil circuit of different engines are different, it is not difficult to diagnose the fault of low oil pressure according to the above ideas.
What is the reason for the low oil pressure?
(1) The oil pressure gauge is faulty or the oil circuit leading to the oil pressure gauge is blocked. Loosen the nut or bolt connecting the oil pipe to the oil pressure gauge (the other end is connected to the main oil circuit), and observe that the oil pressure is high, indicating that the pressure gauge is faulty or the oil pipe leading to the oil pressure gauge is blocked.
(2) Insufficient engine oil capacity, engine oil deterioration or water in engine oil. Regularly check the scale of the oil storage dipstick in the oil pan and fill it up as required; Check the fit between piston ring and cylinder liner, and repair it if it is seriously worn.
(3) The brand of the oil is wrong, and its viscosity is small, resulting in the oil being too thin. Replace the engine oil with new oil that meets the specifications.
(4) The diesel engine is overloaded for a long time, which makes the oil temperature too high and thin. Reduce the load of diesel engine, and do not allow long-term overload work.
(5) The oil filter is blocked, which reduces the oil intake and the pressure is too low. Clean the oil filter screen.
(6) The oil is too dirty, and it will deteriorate after being used for a long time, which will block the filter screen or oil circuit of the oil suction tray. The oil should be replaced with new oil, and the screen and oil passage should be cleaned.
(7) After the oil pump is worn, the internal leakage of the oil pump increases, which reduces the amount of oil pumped, or the paper pad of the oil pump is damaged and leaks oil. It can be compensated by reducing the thickness of the gasket of the oil pump end cover. If the oil pump capacity is still insufficient, repair or replace worn parts and damaged gaskets.
(8) Check whether the spring of the pressure limiting valve is too soft and the valve is too worn. If the valve is worn normally, check whether the spring force is insufficient. The spring can be disassembled and tested on the test bench. Generally, it is not allowed to adjust at will. The steel ball and seat of the pressure limiting valve are worn, the seal is not tight, and oil leaks, which makes the sealing performance lose. When the valve seat is slightly worn, the inclined plane can be ground with valve sand. The ball valve can also be placed on the valve seat with a steel ball and supported by a copper rod, and it can be closed by tapping several times.
(9) The oil circuit from the oil suction plate to the oil pump is not tightly assembled, and there is leakage, such as the hollow bolt of the oil suction pipe is not tightened. Reinstall to eliminate air leakage.
(10) The main bearing, connecting rod bearing, camshaft, shaft sleeve and other lubricating parts are worn, the clearance is increased, and the lubricating oil leaks too much. Repair and replace new parts, restore the matching relationship of spare parts, and make the gap within the normal range.
(1 1) The outer rotor of the rotary oil pump is installed backwards, which reduces the pumping capacity. Reinstall, so that the chamfered end of the outer rotor is installed in the oil pump body.
(12) The oil filter is blocked. At this time, the opening pressure of the safety valve is high, which increases the oil pressure in front of the filter, forces the internal leakage of the oil pump to increase, reduces the amount of oil in the main oil circuit, and leads to the reduction of oil pressure. Clean the oil filter element regularly to eliminate blockage. On the oil pump test bench, readjust the opening pressure of the safety valve. When replacing the filter element, be sure to pay attention to the number and position of felt pads and install them accurately.
German oil manufacturer | What is the reason for low oil pressure?
In addition, when the engine is working, if the oil pressure is always too low, and the crankshaft main bearing, connecting rod bearing or camshaft bearing have abnormal noise. , should check the bearing clearance that produces abnormal noise. According to the test, the oil pressure will decrease by 0.0 1MPa when the clearance of crankshaft main bearing increases by 0.01mm. ..