Suitable for collecting car maintenance knowledge to teach you troubleshooting

Suitable for collecting car repair and maintenance knowledge to teach you how to troubleshoot

Black smoke from trachea

Error: True error.

Cause analysis: indicates that mixture is too rich and combustion is incomplete. The main reason is that car engine is overloaded, there is insufficient pressure in cylinders, engine temperature is too low, carburetor is incorrectly adjusted, air filter is clogged, some cylinders do not work, ignition is too late. When removing, check whether air damper is fully open in time, and if necessary, carry out maintenance; look at main jet from side of carburetor port after flame is turned off, whether there is oil leakage or dripping, oil level in float chamber is too high, and it should be adjusted according to specified range, Tighten or replace main measuring hole, air filter is clogged, it is necessary clean, dry or replace.

2. Blue smoke coming out of car exhaust

Error: True error.

Cause Analysis: This is caused by a large amount of engine oil entering cylinder and failing to burn completely. Remove spark plug, you may find serious deposits. It is necessary to check if oil level on dipstick is too high, if clearance between cylinder and piston is too large, if piston ring is installed backwards, if intake valve guide is worn, and if sealing ring is worn. damaged;

3. White smoke comes out of car's exhaust pipe, which is a serious problem when car is cold, but after car warms up, no white smoke comes out

Misjudgment: False error.

Cause Analysis: This is because gasoline contains water and engine is too cold. At this time, fuel entering cylinder is not completely burned, causing mist points or water vapor to form white smoke. White smoke is often seen when starting a car for first time in winter or during rainy season. It doesn't matter, as soon as engine temperature rises, white smoke will disappear. This state is maintenance free.

4. Engine noise is loud. When car depresses accelerator pedal, a "boom, boom" sound is heard and vibration is felt in engine compartment

Wrong decision: Usage error.

Cause analysis: When car is raised, you can see bumps on bottom engine skid plate. If there are obstacles on road and they are forced to go around, lower engine cover will hit. After deformation of bottom protection plate, distance between engine oil pan and engine oil pan becomes smaller. If distance is too short, when oil pan collides with bottom protection plate during acceleration, it will produce abnormal noise and vibration of car body. Therefore youmust carefully observe road surface while driving, so as not to cause phenomenon of subsidence. Treatment method: remove bottom protective plate, flatten and fix.

5. Car steering wheel is always out of adjustment, turns left for a while, turns right for a while, erratic

Error: True error.

Analysis of causes: rubber stop fixed in steering gear groove is completely damaged. After installing a new limiter, malfunction disappeared completely.

6. Every time air conditioner is turned on, a very bad smell comes out of air outlet, especially in humid weather

Failure detection: maintenance errors.

Cause analysis: The refrigeration principle of an air conditioner is to quickly evaporate and absorb heat through refrigerant, so that temperature of air passing through it drops rapidly. Since temperature of evaporator is low and air temperature is high, particles of water molecules in air will condense into water droplets on evaporator, and dust in air or fine lint on clothes and seats is easy to stick. on surface of condenser, leading to growth of mold and bacteria. Long-term inhalation of such air by human body will affect health of driver and passengers, so air conditioning system should regularly replace air conditioner filter element to clean air duct.

7. Windshield not clear when it rains

Failure detection: maintenance errors.

Cause analysis: It is convenient to use wiper when it is not raining heavily, but when wiper is turned on during light rain, you will find that wiper leaves uneven rubbing marks on glass surface. stick to glass and impair vision. This condition indicates that wiper blades have hardened. The wiper uses rotational energy of motor to convert it into reciprocating movement of connecting rod and transmits this force to wiper arm.

When rubber part of wiper is not hardened, wiper cannot be firmly attached to glass surface, or wiper blade is scratched, resulting in uneven wiping and residual dirt. Replacing windshield wiper or windshield wiper film is very simple. However, it should be noted that when replacing installation method and length of wiper differ in different models and years. Replacing some windshield wipers is very easy. However, it should be noted that when replacing installation method and length of wiper differ in different models and years. Some wipers only need to replace rubber cap, while some wipers need to be replaced as a whole.

8. Cars are noisy

Misjudgment: False error.

Analysis of causes. It doesn't matter dearabout a car, budget, imported, domestic, new or old, noise level may be different. The noise inside car mainly comes from 5 aspects such as engine noise, wind noise resonance, car body, suspension and fruit sound. When car is running, engine is running at high speed, and noise is transmitted to car through firewall, bottom wall, etc.; body resonance created by a car driving on bumpy roads, or through windows opened while driving at high speed, cannot cause resonance, will become noise.

Because of narrow space inside car, noise cannot be effectively absorbed, and mutual influence sometimes causes resonance in car. While driving, noise generated by vehicle's suspension system and noise generated by tires may pass through chassis and enter interior of vehicle. Different suspension methods, different tire brands, different tire models, and different tire pressures also produce different noises; different body shapes and different driving speeds create different wind noise. As a general rule, higher driving speed, greater wind noise.