What Happens When a Car's Air Conditioning Compressor Fails?
3 Answers
When a car's air conditioning compressor is damaged, it can lead to the air conditioning system not working or having poor cooling performance. Obvious symptoms include the compressor failing to rotate, abnormal noises during rotation, abnormal pressure readings (low high pressure, high low pressure, or both high and low pressures with no changes). Methods to determine the condition of the car's compressor: When there is a certain amount of refrigerant in the system, disconnect the compressor's low-pressure pipe, block the high-pressure side after installing a pressure gauge pipe, then increase the engine speed to about 2000 RPM. The compressor's high pressure should be around 1.5MPa, and there should be no significant pressure change within a few minutes after the engine is turned off, indicating good compressor performance. Otherwise, the compressor may be considered subpar. The main failure points of a car's air conditioning compressor include: 1. Damage to the intake and exhaust valves. 2. Burnout of the compressor's electromagnetic clutch coil. If the intake and exhaust valves are damaged, the compressor must be replaced. If the compressor's electromagnetic clutch coil is burned out, it can be replaced separately.
Last time I drove to the city, the air conditioning compressor suddenly failed, with the most obvious symptom being the complete loss of AC function. When I pressed the AC button, no cold air came out at all—only hot or ambient air, which was especially unbearable in summer, making the car feel like a steamer. I also frequently heard abnormal 'clicking' or 'humming' noises from the engine bay, particularly louder during acceleration, which are signs of internal component wear or seizing. If the compressor completely seizes, the belt might slip or even break, creating a hazardous situation. Another issue is that refrigerant could leak from damaged parts, causing a sudden drop in system pressure and rendering the entire AC system ineffective. In such cases, I recommend first checking if any warning lights on the dashboard are illuminated or, after parking, using a stethoscope to listen for unusual sounds near the compressor. If anything seems off, promptly visit a repair shop to inspect the refrigerant and electrical components. Otherwise, prolonged driving could easily lead to heatstroke or fatigue.
I experienced a situation where the compressor failed. At that time, the air conditioning stopped working on the highway, and the temperature inside the car soared to 40 degrees. I was drenched in sweat and had to open the windows, but the noise was unbearable. The key issue was that the cooling capability was completely gone—even setting the temperature to the lowest had no effect. When I pressed the air conditioning button, only air came out, with no coolness at all. I also noticed that the fan was running normally, but the compressor's electromagnetic clutch wouldn't engage, preventing the system from starting. Later, during repairs, it was discovered that the compressor bearing had failed, costing thousands to replace. Now, I check the air filter and belts monthly for any abnormal wear to prevent sudden failures. Traveling in summer without air conditioning is a nightmare, so timely maintenance is crucial.
