General knowledge of vehicle maintenance

2024-09-19 11:22:12

Today, the small edition of Car maintenance equipment for everyone to popularize the knowledge of the common maintenance of cars

Black smoke was rising from the exhaust pipe

Fault diagnosis: True fault.

Cause analysis: It shows that the mixture is too thick and the combustion is not complete. The main reasons are automobile engine overload, insufficient cylinder pressure, too low engine temperature, improper carburetor adjustment, air filter blockage, individual cylinders do not work and ignition too late. When eliminating, check whether the choke is fully opened in time, and repair if necessary; After flameout, look at the main nozzle from the carburetor port, if there is oil injection or dripping oil, the oil level of the float chamber is too high, should be adjusted to the specified range, tighten or replace the main measuring hole; The air filter is blocked and should be cleaned, dredged or replaced.

The engine noise is large, when the vehicle steps on the accelerator pedal in place, there is a "long, long" abnormal sound, and there is a sense of vibration in the engine compartment

Fault determination: Use class fault.

Cause analysis: Lift the vehicle, you can see the bottom of the engine protection plate bump marks. If there are obstacles on the road and forced through, the engine bottom protection plate will be bumped. After deformation, the distance between the bottom guard and the engine oil pan becomes closer. If the distance is too close, the oil pan and the bottom guard will collide with each other when accelerating, and the body will vibrate. Therefore, driving must carefully observe the road surface, do not cause drag bottom phenomenon. Treatment method: Remove the bottom protection plate, flatness correction can be.

Every time the air conditioner is turned on, its outlet has a very bad smell, which is more serious when the weather is wet

Fault diagnosis: A maintenance fault.

Reason analysis: The refrigeration principle of air conditioning is to absorb heat through the rapid evaporation of refrigerant, so that the temperature of the air flowing through the rapid decline. Because the temperature of the evaporator is low, and the air temperature is high, the water molecular particles in the air will condense into water droplets on the evaporator, and the dust in the air or the small fluff on the clothes and seats are easy to attach to the surface of the condenser, resulting in mold and bacteria will multiply. Such air is inhaled by the human body for a long time will affect the health of drivers and passengers, so the air conditioning system should regularly replace the air conditioning filter and clean the air duct.

In the low temperature in winter, the car is parked for a long time, and the engine is more difficult to start

Fault diagnosis: False fault.

Cause analysis: Due to the low temperature, the gas rate of the fuel decreases, and the mixture becomes thin and not easy to burn, resulting in difficulty in starting. At the same time, due to the low temperature, the oil viscosity becomes larger, and the engine running resistance increases, causing difficulty in starting. In addition, the chemical reaction of the battery electrolyte is slow, resulting in insufficient power output when starting, insufficient starter power and insufficient ignition voltage, making the engine difficult to start. Therefore, the car should preheat the engine before starting in the cold season. Hot water or steam can be injected into the radiator and water jacket, and the temperature in the water jacket is transmitted to the cylinder wall, so that the fuel entering the cylinder is easy to vaporize when starting, and the temperature of the combustible mixture can be increased to facilitate combustion. The battery can also be preheated according to the need to enhance the battery power, improve the starting current and ignition voltage.

The exhaust pipe of the vehicle emits white smoke, which is serious when the cold car, and does not emit white smoke after the hot car

Fault diagnosis: False fault.

Reason analysis: This is because the gasoline contains water, and the engine is too cold, and the fuel entering the cylinder is not completely burned, resulting in fog points or water vapor formation of white smoke. Winter or rainy season when the car is first started, white smoke can often be seen. It doesn't matter, once the engine temperature rises, the white smoke will disappear. This condition does not need to be repaired.

The tailpipe of the vehicle emitted blue smoke

Fault diagnosis: True fault.

Reason analysis: It is due to a large number of oil into the cylinder, and can not be completely burned. Remove the spark plug, you can find serious carbon accumulation phenomenon. Check whether the oil level of the oil gauge is too high; Whether the clearance between cylinder and piston is too large; Whether the piston ring is inverted; Whether the intake valve guide is worn or the seal ring is damaged; Whether the cylinder gasket is ablated, etc., should be repaired if necessary.

The steering wheel of the vehicle is always wrong, now to the left, now to the right, drifting

Fault diagnosis: True fault.

Cause analysis: This is due to the rubber limit block fixed in the groove of the steering machine has been completely damaged. After installing the new stop block, the fault disappeared completely.

The windscreen can't be scraped clean during light rain

Fault diagnosis: A maintenance fault.

Reason analysis: When it is not raining very much, the wiper feels good, but when the wiper is started in the light rain, it will be found that the wiper will leave uneven traces of wiping on the glass surface; Sometimes it gets stuck in the glass and causes bad vision. This condition indicates that the wiper blade has hardened. The wiper is transformed by the rotational energy of the motor into a one-to-one movement by the connecting rod, and the force is transmitted to the wiper arm.

When the rubber part of the wiper is not hardened, the wiper will not be able to fit closely with the glass surface, or the wiper sheet will cause uneven wiping, forming residual dirt. The wiper or wiper film face is simple to replace. However, when replacing it, it should be noted that the installation method and length of the wiper are different in the model and year. Some wiper film replacement is very simple. However, when replacing it, it should be noted that the installation method and length of the wiper are different in the model and year. Some wipers only need to replace the rubber sheet, and some wipers need to be replaced as a whole.

The engine temperature is suddenly too high during operation

Fault diagnosis: True fault.

Cause analysis: If the car is in operation, the coolant temperature gauge indicates that it will soon reach the position of 100 ° C, or when the cold car is started, the engine coolant temperature rapidly rises to boiling, and turns to normal after the coolant is filled, but the engine power decreases significantly, indicating that the engine mechanical system fails. Most of the reasons for this kind of failure are: serious water leakage of cooling system; The cylinder gasket separating the water jacket from the cylinder is washed out; Thermostat main valve off; Fan drive belt loose or broken; Water pump shaft and impeller loose; The fan clutch does not work properly.

The oil pressure indicator lights up when the car accelerates

Fault determination: true and false faults coexist.

Cause analysis: There are real and virtual situations when the oil lamp is lit. The so-called real is that the oil pressure is really low, low to the extent of the indicator light warning, indicating that the lubrication system is indeed faulty and must be eliminated. The so-called virtual, as suspected, the oil lubrication system is not faulty, but the oil pressure indicator system is faulty, and the indicator light is lit in the wrong place. Although this failure will not affect the normal operation of the engine, it should also find the root cause in time and eliminate it. Under normal circumstances, the possibility of real symptoms is greater, and it should be used as the main idea to judge the fault.

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