What Causes the Loud Noise When the Car Fan is Turned On?

[LaVera]

When the car fan is turned on and produces abnormal noise, it is usually due to deformed fan blades, a damaged motor, or dirt and blockages in the air conditioning system. The fan automatically activates when the water temperature exceeds 95 degrees Celsius. If the fan blades are deformed, they will generate loud noise during rotation. Similarly, a damaged fan motor can cause abnormal fan speed, resulting in unusual sounds. Dirt and blockages in the air conditioning system can lead to excessive airflow noise. It is recommended to clean the air conditioning system. Typically, the cabin air filter should be replaced every 10,000 to 20,000 kilometers. If the environment is particularly dusty, the replacement interval should be shortened. Over time, the air conditioning system's pipes may develop mold or accumulate debris, so it is advisable to clean them every 30,000 to 40,000 kilometers. The car air conditioning system mainly consists of a refrigeration system, heating system, air distribution system, control system, and air purification system. The refrigeration system includes components such as the evaporator, air conditioning compressor, condenser, liquid storage tank, expansion valve, and high/low-pressure pipelines. The heating system primarily comprises a heater core, water valve, and blower motor. The system operates based on signals from various sensors that detect cabin temperature, evaporator temperature, engine coolant temperature, and other relevant switch inputs. These signals control the radiator fan, condenser fan, compressor clutch, blower motor, and air control motor to automatically regulate the cabin temperature.