Why is there abnormal noise when starting with the air conditioning on?
2 Answers
The reasons for abnormal noise when starting with the air conditioning on are as follows: Abnormal noise from the car's air conditioning compressor: As a high-speed rotating component, the air conditioning compressor has a relatively high probability of failure, with abnormal noise being a common issue. There are many causes for compressor noise, such as damage to the compressor's electromagnetic clutch or severe internal wear of the compressor, both of which can produce abnormal noise. Internal abnormal noise: Internal abnormal noise is usually caused by the presence of air or moisture in the refrigerant of the system, which generates noise during the evaporation and expansion of the refrigerant. Users may perceive this as noise coming from inside the dashboard. Repeated engagement of the electromagnetic clutch: Insufficient power generation from the alternator, excessively high pressure in the air conditioning system, or excessive engine load can all lead to repeated engagement of the electromagnetic clutch, resulting in abnormal noise from the air conditioning.
Every time I start the car and turn on the AC, I often hear squeaking or gurgling sounds, which is annoying but common. When the engine is just started, the RPM is still low, and turning on the AC suddenly increases the load, which may cause the belt to slip and produce noise, especially in hot summer when the belt is prone to aging or insufficient tension. If the fan blades are covered with dust, they can also make strange noises when spinning. The compressor itself makes slight noise when starting, but excessive noise may indicate a damaged bearing or loose installation. Once during a road trip, my AC kept making noise, and a check at the repair shop revealed a loose compressor connection—tightening it fixed the issue. These minor problems are easier to fix if detected early; don’t wait until the belt breaks. Safety comes first when driving, so if you encounter such issues, pull over to check or consult a professional mechanic.
