Core hints: judgment and elimination of abnormal oil pressure failure of diesel engine: diesel engine, due to wear, improper assembly or other failure, will cause low oil pressure or no pressure; excessive oil pressure or pressure meter pointer swinging. So that the accident caused by the use of construction machinery, resulting in unnecessary losses.
Diesel engine, due to wear, improper assembly or other failures, can cause low oil pressure or no pressure; excessive oil pressure or pressure meter pointer swinging. So that the accident caused by the use of construction machinery, resulting in unnecessary losses.
1. low oil pressure
When the oil pressure gauge indicates that the pressure is lower than the normal value (0.15 - 0.4 MPa), the machine should be stopped working immediately. After waiting for 3 - 5min, the quality and quantity of the oil will be checked out. If the oil is insufficient, if the oil viscosity is small, the oil level is raised and the oil is raw, then the oil is mixed with the oil. If the oil color is milky white, the oil is mixed with water. The fault of oil leakage or leakage should be checked and the oil is replaced when necessary. When the oil meets the requirements of the diesel engine and the quantity is sufficient, the main oil channel screw plug is loosened and the crankshaft is rotated. If there is more oil, the clearance gap between the main bearing, the connecting rod bearing and the camshaft bearing is too large. The clearance of the bearing should be checked and adjusted. If the oil is less, it may be the blockage of the coarse filter and the pressure limiting valve. Improper oil leakage or improper adjustment should be done by cleaning the coarse filter or checking and adjusting the pressure limiting valve. The adjustment of the pressure limiting valve should be carried out on the experimental platform, generally not allowed to be adjusted at will. In addition, if the oil pump is seriously worn or the seal is damaged, the oil pump does not pump oil, and the oil pressure is too low. At this time, it is necessary to check and repair the oil pump. If the above inspection is carried out, the result is not abnormal, indicating that the oil pressure gauge should be malfunctioning, and the new oil pressure gauge should be replaced.
2. no oil pressure
During the operation of the construction machinery, if the oil indicator light is shining and the oil pressure gauge pointer is "0", the machine should be stopped immediately and turned off. Then check whether the oil pipe is leaking because of sudden rupture; if there is no oil leak in the engine's appearance, the pipe joint of the oil pressure gauge, if the oil is fleeing rapidly, indicates that the oil pressure gauge is damaged. As the oil filter is mounted on the cylinder, there should be a paper pad in general. If the paper pad is misplaced or the oil hole is connected to the oil hole of the oil, the oil can not enter the main oil channel. This is quite dangerous, especially for the diesel engine, which has just been overhauled. If no abnormal phenomena are found through the above check, it is indicated that the fault may be on the oil pump, and the oil pump should be inspected and repaired.
3. high oil pressure
In winter, after starting the diesel engine, the oil pressure will be found to be high, and the oil pressure will be reduced to normal after preheating. If the indication value of the oil pressure gauge still exceeds the normal value, the pressure limiting valve should be adjusted to meet the specified value. After the test, if the oil pressure is still high, you need to check the number of the oil, see if the oil viscosity is too large; if the viscosity of the oil is not large, it may be a blockage in the lubricating oil channel, then clean with clean diesel oil. Because of the poor lubricity of diesel oil, the starter can be rotated for three to four minutes with the crankshaft. If you have to start the engine for cleaning, you can use 2 / 3 wash oil and 1 / 3 oil mixture to clean it, and the time should not exceed 3min.
4. the pointer of the oil pressure meter swings back and forth
After starting the diesel engine, if the pointer of the oil pressure meter is found to swing back and forth, it should be first drawn out to check whether the oil is sufficient, when the oil is insufficient, the qualified oil should be added in accordance with the standard, and the bypass valve should be checked under the condition of sufficient oil. If the bypass valve spring deformation or insufficient elasticity, the bypass valve spring should be replaced; if the bypass valve is closed, the bypass valve should be repaired.
