- Low refrigerant level: When your AC system is low on refrigerant, it forces the compressor to work harder than it should in order to produce cool air. This can cause parts within the compressor to loosen and generate a squealing noise.
- Faulty compressor clutch: The clutch is responsible for engaging and disengaging the compressor with the engine. If the clutch is worn or damaged, it can generate a squealing sound when it slips.
- Worn or broken belt: The belt is the primary connection between the engine and the AC compressor. As it begins to wear out or if it has snapped, it can generate a squealing noise.
- Failed compressor bearing: The compressor contains bearings that help the compressor shaft rotate smoothly. If these bearings wear out or fail, they can cause a squealing noise to occur.
- Faulty compressor valve: The compressor valves control the flow of refrigerant through the system. If a valve becomes damaged or worn, it may generate a squealing sound.
