How to Determine if a Car's Air Conditioning Compressor is Faulty?
3 Answers
After turning on the car's air conditioning cooling switch, if the cooling effect deteriorates and the engine speed does not increase, it can be determined that the compressor has a problem. The following is a related introduction about the air conditioning compressor: 1. The reasons for air conditioning compressor damage include: damage to the compressor valve plate; damage to the compressor cylinder head gasket; damage or deformation of the compressor exhaust valve; foreign objects in the compressor exhaust valve gasket. 2. The compressor is the heart of the car's air conditioning refrigeration system, responsible for compressing and transporting the refrigerant. Compressors are divided into two types: fixed displacement and variable displacement. According to different working principles, air conditioning compressors can be divided into fixed displacement compressors and variable displacement compressors.
I've been in auto repair for over 20 years, and there are quite a few ways to check if an AC compressor is good or bad. Listening to the sound is key: start the car and turn on the AC, the compressor should hum smoothly. If there's no sound, the clutch might be stuck or damaged; if it's squealing loudly, there's definitely wear. Then check the cooling effect—if the vents aren't cold after a few minutes, the compressor's efficiency is low. Also, look for oil leaks—squat down and check near the compressor under the car for any oil stains, as leaks are common with aging. It's best to use a pressure gauge to test the high and low pressures—normal range is between 25 to 45 PSI; anything outside that means internal issues. Regular maintenance of the AC system can reduce the chance of compressor failure, and since repairs cost a few hundred bucks, it saves money in the long run.
Having driven for urban commuting for over a decade, I find it fairly easy to assess the condition of an air conditioning compressor. Before driving, press the AUTO button for the AC and wait briefly. If no cold air comes out, the compressor is likely faulty. Pay attention to the humming sound under the hood—a slight vibration is normal, but loud noise or complete silence indicates a problem. If the AC indicator on the dashboard stays lit continuously, it might also signal compressor failure. You can check under the car for oil leaks; if it's wet, get it repaired promptly. Seasonal factors matter too—frequent AC use in summer increases load, leading to earlier wear. Replenishing Freon and maintaining pressure during servicing can extend its lifespan.
