01
First, the oil pressure has been very low
No matter what speed or temperature the engine is, the oil pressure indicator indicates that the oil pressure is always below 69kPa, and the oil pressure alarm lamp flashes.
The main reasons are:
1. engine oil quantity, oil quality does not meet the requirements. If the oil in the oil pan is too little, the oil becomes thinner, the viscosity decreases, and the oil is mixed with water, diesel oil, gasoline, etc..
2. pump serious wear or improper assembly, the pump oil pressure is not up to the requirements, the oil pump leak too much inside.
3. oil collection strainer or filter is seriously blocked by oil sludge, and the oil is difficult to enter the main oil duct.
4. machine oil pump inlet pipe joint seal is not strict, there is a serious suction phenomenon.
5. there is a serious leakage phenomenon in the lubricating oil, which causes the oil in the main oil passage to flow back from the leaking to the oil pan and relieve the pressure. Parts of the leakage mainly has: the technology of oil on the body wall loosening; oil pipe rupture; crankshaft neck centrifugal purification oil cavity plug loose; crankshaft bearing or cam of uranium bearing clearance is too large and so.
6. oil pressure gauge and induction plug failure (induction plug wire directly remove the ground, if the pressure returned to normal, indicating induction plug damage).
02
Two, the oil pressure suddenly drops to zero
Engine operation, the oil pressure from the normal value suddenly dropped to zero, at this time should immediately stop inspection, so as not to lead to burning tile accident.
The main reasons are:
1. oil sump oil drain plug loose or broken, oil cracking oil, large leakage.
The 2. return valve is loosened and the oil is returned to the oil pan from the return valve.
3. oil strainer filter foreign body was suddenly blocked, the oil can not enter the main oil gallery.
4. machine oil pump drive shaft and transmission pin broken, the oil pump stopped running suddenly.
5. oil pressure gauge suddenly damaged.
03
Three, the engine oil pressure drops after the machine temperature rises
The engine oil pressure is normal when the engine cooler (just started), and the engine oil pressure drops gradually with the increase of engine temperature.
The main reasons are:
When the engine temperature rises, the oil viscosity decreases, and the leakage loss of lubricating oil increases. If the oil deterioration, grade does not match, or crankshaft journal and bearing, camshaft neck and bearing clearance is too large, such a situation will happen.
04
Four, the higher the engine speed, the lower the oil pressure
When the engine is in small throttle, the oil pressure is normal. After the throttle is increased, the indicator value of the oil pressure indicator drops or even tends to zero, and the oil pressure tends to be normal after reducing the throttle.
The main reasons are:
1, there are car wash cloth, paper, floc impurities in the oil pan. When the engine runs idle, the vacuum suction of the oil pump is small, and the sundries are suspended at the bottom of the oil at the bottom of the oil pan, and the oil supply is normal. When the engine speed is increased, the vacuum suction of the oil pump is increased, and the sundries suspended in the oil are adsorbed on the filter net, blocking the filter screen to make the oil supply unsmooth and the oil pressure drop. After the throttle is lowered, the suction of the oil pump is reduced, and the sundries are suspended in the oil under the action of self weight, and the oil supply is normal and the oil pressure rises again.
2, the plastic texture filter screen changes in the heat engine, after the throttle, the central part of the filter screen is sucked up, blocking the oil inlet pipe, so that the oil supply suddenly interrupted.
3, the pressure regulating valve, return valve spring break, increase the throttle after the ball valve open back pressure, but after the oil pressure reduced, the spring can not make the ball valve back, resulting in continuous reduction of oil pressure.
