What Causes the Unusually Loud Noise from the Car's Air Conditioning Compressor?
2 Answers
Damage to the compressor's electromagnetic clutch or severe internal wear of the compressor can cause abnormal noise. Below is relevant information about the compressor: Introduction: A compressor is a type of driven fluid machinery that elevates low-pressure gas to high-pressure gas, serving as the heart of the refrigeration system. Principle: It draws in low-temperature, low-pressure refrigerant gas through the suction pipe, compresses it via piston movement driven by the motor, and then discharges high-temperature, high-pressure refrigerant gas through the discharge pipe, providing power for the refrigeration cycle. This enables the refrigeration cycle of compression→condensation (heat release)→expansion→evaporation (heat absorption).
Last time I drove with the AC on, the compressor was so noisy it almost scared me into pulling over. This situation is mostly caused by a loose or severely worn compressor belt—the noise comes from the belt slipping. Checking the belt is quite simple; just press it to see if it still has enough elasticity. Another common cause is a failed compressor bearing. As the car ages, the bearings tend to wear out, causing a squeaky noise when rotating. Insufficient refrigerant or air mixed into the system can also amplify abnormal noises because it makes the compressor work harder. Another possibility is an issue with the clutch—if the noise is especially loud when turning the AC on or off, it’s likely due to clutch sticking. All these issues relate to driving safety. Loud noises aren’t just annoying; they could escalate into system failures. I recommend taking the car to a repair shop as soon as possible for a professional inspection, especially before any long trips.
