Caused the main reason for the low oil pressure: 1, insufficient oil fuel oil if the oil amount, will reduce oil pump pump oil or by entering the air pump oil, the oil pressure drop, the crankshaft and bearing, cylinder liner and piston will aggravate wear due to bad lubrication.
2, the oil pump does not turn if oil pump drive gear and the drive shaft of flat key damage or loss;
Set filter damaged the oil pump suction foreign body, the gear is jammed, can make oil pump stops, the oil pressure drop to zero.
3, oil pump, oil pump pump shaft and bushing wear machine, gear clearances between the clearance between the pump cover and end face due to abrasion, backlash, or radial clearance is too large, will lead to pump oil decreases, and makes oil pressure drops.
4, the engine temperature is too high too much if the engine cooling system scale, the heat dissipation, long time overload operation or fuel injection pump fuel supply time too late, can make the engine overheating, accelerate the aging of the oil, metamorphism, become loose, leakage from the tolerance clearance, lower pressure.
5, with the main bearing and connecting rod bearing clearance increase engine use for a long time after the crankshaft and connecting rod bearing fit clearance increases gradually, leakage, oil pressure drop.
6, damage to the bypass valve, in order to keep the main oil passage of normal hydraulic equipped with by-pass valve, if the pressure regulating spring softening or improper adjustment, seat and ball matching surface wear or stuck and closed lax, oil return quantity increase, the main oil pressure drops.
7, oil radiator leak leakage will contaminate engine surface and pressure drop;
Make the oil leakage into the water tank, cooling system of heat dissipation effect, engine overheating, oil is thinning, pressure drop.
8, oil pressure sensor failure or road congestion if oil pressure sensor failure or main way to road congestion and oil pressure sensor is confusing, the oil pressure drops.
9, a pressure limiting valve set pressure is too low in the lubrication system, oil pump pumping oil before reaching the engine lubrication components, must ensure that the appropriate pressure.
If the pressure limiting valve set pressure is too low, pressure regulating spring softening or leak sealing surface, can cause the set pressure is too low.
10 the engine oil, oil of inappropriate if choose inappropriate or inferior oil, when the engine is running will be due to the low viscosity increased leakage, pressure is reduced.
11, oil filter clogging when oil filter clogging and cannot flow, located in the base of the bypass valve is opened, the oil filter without direct access to the main oil passage.
If the by-pass valve opening pressure is set too high, when the oil filter is blocked will not be able to open in time, oil pump pressure will increase, the leak will increase, the main oil passage of oil decreases, and the oil pressure drops.
12, set filter clogging in normal circumstances, when the oil pressure in the gas should be higher than small throttle, but sometimes also can appear abnormal situation.
If the oil dirty, sticky, easy to plug set filter.
When the engine small throttle speed, due to the oil pump, oil absorption is the main oil way to establish a certain pressure, it is so normal oil pressure;
But when step on the gas in high speed, an oil absorption of oil pump will set filter and significantly reduce the resistance is too high, so because of the shortage of lubricating oil in oil, the oil pressure gauge in value instead of down.