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60 Vehicle Regular Fault and Solution Part 3

Nov 12, 2021

21. The engine of the newly purchased vehicle shakes seriously, and sometimes the fault indicator light flashes occasionally

Fault determination: false fault.

Cause analysis: This is the case for some new vehicles. The vehicle engine shakes seriously, and sometimes the fault indicator will flash occasionally. Many people suspect that the vehicle has quality problems. In fact, the real reason is that the unclean fuel leads to the pollution or blockage of the fuel supply system. At present, some advanced vehicles are equipped with exhaust emission monitoring system. Because this control system can very sensitively detect vehicle exhaust emission and fuel cleanliness, the use of dirty fuel will cause fuel supply, ignition and emission system pollution, which will lead to engine fault indicator lighting and engine shaking in varying degrees.

Solution: after thoroughly cleaning the polluted system, continuously add gasoline with stable index performance and add a certain amount of oil circuit cleaner to improve the situation.

22. The lifting speed of power windows is different from door to door

Fault determination: false fault.

Cause analysis: generally, some sand and dust enter the glass lifting track, which increases the friction resistance between the glass and the groove, resulting in this result.

Solution: as long as the corresponding cleaning can solve the problem.

23. The vehicle vibrates slightly when the automatic transmission is in position D

Fault determination: false fault.

Cause analysis: when the vehicle is ready to start, when the automatic transmission is put into gear d, the first gear friction plate is engaged under the action of the hydraulic torque converter to produce a forward driving force. At this time, the forward force is prevented by stepping on the brake pedal, resulting in slight vibration of the vehicle. If the vibration is too large, the friction plate of the forward gear of the transmission may be worn, and the transmission needs to be repaired; It may also be caused by engine support or automatic transmission support pad damage and resonance Su engine misfire.

Solution: pay attention to the normal vehicle status so that abnormalities can be found in time.

24. The engine oil just changed and it turned black soon

Fault judgment: false fault.

Cause analysis: there are two main reasons for blackening. Firstly, it is due to the role of detergent dispersant, and secondly, it is due to the oxidation of engine oil in use. If an engine oil remains black in use, it means that the engine oil has not played its normal cleaning role at all. The current engine oil generally contains a detergent dispersant to absorb the carbon deposit generated by combustion and the oxide of engine oil, so as to replace it during oil change, so as to ensure the cleanness of the engine interior. Therefore, the blackening of the oil just replaced is not necessarily caused by too dirty inside the engine, as long as the oil can be changed at the specified time.

Solution: change the oil and oil filter regularly. After the engine oil is used for a period of time, the viscosity of the engine oil thickens and acid products are produced. If it is replaced irregularly, it will damage the engine components and affect the normal operation of the engine.

25. Abnormal display of engine oil pressure indicator

Fault determination: true fault.

Cause analysis: when the pointer of the gauge shows that the oil pressure is abnormal, it indicates that the engine components are faulty. If the pressure indicated by the pointer of the oil gauge is low or the pointer of the instrument fluctuates greatly, it may be caused by the wear of the oil pump, the blockage of the filter by dirt, the exposed oil surface of the oil suction screen, the low oil level, the mixing of air in the oil circuit and the failure of the pressure gauge. In addition, the low viscosity of lubricating oil, poor sealing and lubricity of oil circuit, too high supercooling viscosity of lubricating oil and too much sludge deposition of lubricating oil will also cause abnormal display of oil pressure indicator.

Solution: go to the repair shop for replacement and repair in time.

26. Excessive engine oil consumption

Fault determination: true fault.

Cause analysis: careful friends will find that there is normal consumption of lubricating oil when the vehicle condition is good, but when the vehicle condition is poor, the tail gas of the vehicle emits blue smoke. In fact, this means that the consumption of lubricating oil is too large. Generally speaking, the consumption of lubricating oil is nothing more than two cases, entering the combustion chamber to participate in combustion, or oil leakage. The reason why the oil can flow into the combustion chamber is mainly because the parts are seriously worn, the matching clearance is too large, or the oil pressure is too high, resulting in the oil flowing into the combustion chamber. The oil leakage is mainly due to the hardening and aging of the sealing gasket and the stuck valve. If it is an old vehicle, the sealing gasket is generally not tightly sealed due to aging.

Solution: you'd better pass the professional maintenance center, be judged by the maintenance engineer, and implement effective solutions.

27. After a period of time, part of the engine oil is consumed

Fault determination: false fault.

Cause analysis: the national standard stipulates that the normal loss of engine oil when the vehicle travels 10000 km should be within 1L. The oil capacity of a general car is about 4L. When the oil level reaches the mark line min of the oil dipstick, the oil is less than 0.5-1L. If the engine oil loss is less than 1L within 10000 km, it is a normal loss and can not be regarded as a fault.

28. The throttle body and idle motor of the engine are dirty

Fault determination: true fault.

Cause analysis: at present, the idle speed of the car engine is controlled by the idle stepping motor installed on the throttle body. When the engine is running, due to the air quality and gasoline quality, there will be a lot of dirt on the throttle valve and idle valve of the engine throttle body. When the dirt is serious, the engine will have low idle speed, poor stability or no idle speed, and the valve will be stuck during refueling.

Solution: it is recommended to clean the throttle body every 20000 km. After cleaning, set the engine to normal working state through the diagnostic instrument.

29. When the vehicle accelerates rapidly, the speed cannot be raised

Fault determination: true fault.

Cause analysis: the vehicle accelerates normally during slow acceleration, but the vehicle speed cannot be increased immediately during rapid acceleration, so it is impossible to overtake. The possible causes are the failure of the fuel supply system of the engine, the oil pressure, fuel injection quantity and ignition time do not meet the specifications, and the failure of spark plugs and high-voltage wires.

Solution: go to the repair shop for replacement and repair in time.

30. When the car is running, the engine exhaust pipe emits black smoke and the exhaust pipe makes abnormal noise.

Fault determination: true fault.

Cause analysis and solutions: 1. If a small amount of black smoke is emitted from the engine exhaust pipe, accompanied by a rhythmic "sudden" sound, it can be concluded that it is caused by a small number of cylinders not working or inaccurate ignition timing. 2. The cylinder by cylinder fire cut-off method can be used to find out the inoperative cylinder, or check and correct the ignition timing. 2. If a large amount of black smoke is emitted from the exhaust pipe of the engine and accompanied by the sound of gunfire, it can be concluded that the mixture is too rich. Timely check whether the choke is fully opened, and conduct high-speed maintenance if necessary. After flameout, look at the main nozzle from the carburetor port. If oil is injected or dripping, the oil level of the float chamber is too high. Adjust it to the specified range, tighten or replace the main measuring hole. The air filter is blocked and should be cleaned or replaced.