Insufficient engine oil reduces the pumping capacity of the oil pump or air intake, which leads to the inability to pump the oil, resulting in the decrease of engine oil pressure. If the engine temperature is too high, it is easy to dilute the oil, and the loss from the mating gap is large, which leads to the decrease of engine oil pressure.
When the oil pump parts are damaged or the gap is too large due to wear and assembly problems, it will lead to the failure of oil pump not producing oil or insufficient oil. Improper fit clearance between crankshaft and large and small tiles will increase oil pressure, and too loose will reduce oil pressure.
Blockage of the oil filter and oil suction pan will also reduce the oil pressure, and the oil return valve will be damaged or out of order. If the spring of the oil return valve in the main oil circuit is fatigued, softened or improperly adjusted, the mating surface between the valve seat and the steel ball is worn or stuck by dirt, the oil return volume will increase obviously, and the oil pressure in the main oil circuit will also decrease.
First, check whether there is a shortage of oil. If there is no problem, measure the oil pressure to see if it is enough. If there is no problem, check the oil level sensor.
How much the alarm light is on does not necessarily mean that there is a shortage of oil. When the oil light is on, stop to check whether there is oil shortage, and just add it. It may be that the oil sensor is broken and the thread falls off, or it may be caused by the pressure relief of the oil pump.
The oil level warning light is a yellow light marked kettle. If it turns red, it means the car can't drive, because red means there is no oil or the oil circuit is blocked.
Extended data:
Automobile fault diagnosis refers to the detection, analysis and judgment of the automobile without disassembly when the automobile has hidden dangers, the technical condition is deteriorated or the working ability is partially or completely lost, so as to determine the technical condition of the automobile or find out the fault position and reason.
In automobile fault diagnosis, some diagnostic parameters are often used to represent the technical conditions of automobile, assembly and machinery, such as working process parameters and state parameters accompanying working process. These parameters include physical quantities (such as vibration, noise, temperature, vacuum degree, power, cylinder compression pressure, etc. ) and chemical quantities (such as waste gas components, lubricating oil impurity components, etc. ).
There are two basic methods for automobile fault diagnosis: one is manual diagnosis, and the other is instrument and equipment diagnosis. Manual diagnosis mainly depends on the practical experience and knowledge of the diagnostician, with the help of simple tools and sensory means such as eyes, ears and hand models. At the same time, check, test and analyze, and then judge the technical condition of the car. This method is simple and intuitive, and it is also the basis of establishing the knowledge base of modern fault diagnosis expert system.
Instrument and equipment diagnosis method is to use general or special instruments and equipment to detect automobiles, assemblies and mechanisms, and provide quantitative basis for analyzing automobile technical conditions and judging faults. Some instruments and equipment controlled by computer or equipped with fault diagnosis expert system can automatically complete the test, analysis, judgment and decision-making of diagnostic parameters of automobile technical condition. In the practice of diagnosis, the two methods are often combined. First of all, the diagnostic personnel ask the driver about the fault, visually inspect the vehicle, and preliminarily judge the fault according to the experience, and then use the diagnostic instruments and equipment to further screen and identify the fault, and finally confirm the fault.
References:
Baidu Encyclopedia-Automobile Fault Diagnosis