Engine oil pressure too low
1. Phenomenon
After the engine is started, the oil pressure quickly drops to zero; while the engine is running, the oil pressure is always too low and the oil pressure warning light comes on; the oil level in the oil pan rises; and there is oil leakage.
2. Reason
Insufficient oil in the oil pan; too small oil viscosity; insufficient spring elasticity or improper adjustment of the pressure limiting valve; serious oil leakage in the lubrication system pipeline; damaged fine oil filter and oil leakage; excessive wear or failure of the oil pump; oil pressure gauge or sensor Failure; the clearance between main bearings, connecting rod bearings, camshaft bushings and other mating parts is too large.
3. Diagnosis and exclusion
① Check the oil level height and oil viscosity in the oil pan. Pull out the oil dipstick and check. If the oil level is too low, add more oil. When the engine oil is too thin, it means that the viscosity is too low or the oil's viscosity-temperature properties are too poor, and the engine oil that meets the standard should be refilled. If the engine oil is emulsified or has water droplets, and the oil level tends to rise, it means that the coolant is leaking into the oil pan. At this time, the leaking location should be identified and eliminated.
②Inspect and maintain the main components of the lubrication system. Remove the wire from the oil pressure sensor, turn on the ignition switch, connect the wire end to the cylinder block, and observe the status of the oil pressure gauge. If the oil pressure gauge pointer quickly rises to the maximum reading, it indicates that the oil pressure gauge is good; if the pointer does not move or rises very little, it indicates that the oil pressure gauge is faulty or the wire is broken, and a new oil pressure gauge or wire should be replaced. When the sensor is damaged, it can be replaced with a new one.
After inspection, if the oil pressure gauge, sensor and filter are all normal, and there is no oil leakage in the pipelines of the lubrication system, the oil pump should be disassembled and inspected, and the filter collector should be cleaned.
③When the engine has been used for a long time and the bearings and other mating parts are severely worn, the bearing bushes should be re-repaired.
