How to Determine if a Car Compressor is Faulty?

[BeckettRose]

Methods to determine if a car compressor is faulty: 1. Air conditioning not cooling: When the AC switch is turned on, the engine speed does not increase. If air conditioning is not needed, removing the compressor's belt can enhance power by more than half a gear without any adverse effects on the car; 2. Exhaust valve damage: If the compressor's electromagnetic clutch coil is burnt out, generally, the only solution is to replace the compressor if the intake and exhaust valves are damaged. The electromagnetic clutch coil can be replaced if burnt; 3. Compressor fails to rotate: There may be unusual noises during rotation, abnormal pressure, high pressure too low, or low pressure too high; 4. The air conditioning compressor is not powered by electricity but is driven by the engine's gears or belt. When the air conditioning is off, the compressor is idling.

[Ryder]

I've been driving for over 20 years and have plenty of experience judging compressor failures. When you turn on the AC in summer and only hot air blows out, the compressor is most likely not working. Start the engine and listen carefully - if you hear rattling or metal grinding noises, it indicates internal bearing damage. Check the belt pulley in the engine bay; if the compressor isn't spinning or the belt is slipping/loose, those are sure signs of trouble. An AC pressure gauge gives more accurate diagnosis - abnormal high/low pressure or refrigerant leakage usually means compressor issues. If you notice unexplained fuel consumption increases during daily driving, a seized compressor can reduce engine efficiency. I remember last business trip when my compressor failed midway - unbearable cabin heat delayed my schedule and cost over 500 yuan in repairs. Early diagnosis saves big money - get these problems checked professionally immediately.

[OliveLynn]

As a young car owner, I only encountered air conditioning issues last year, and it was quite straightforward to diagnose a faulty compressor. When driving with the AC on the highest setting, the cooling was as weak as a fan, and hot air came out of the vents—likely indicating the compressor had failed. Standing in front of the car and listening to the engine bay, if there were strange squeaking or grinding noises resembling something scraping, it’s often a sign of bearing or clutch failure. I foolishly tried adding refrigerant, which only made things worse before finally taking it in for repairs. The mechanic confirmed the compressor was internally seized and needed replacement. The cost was shocking, but safety comes first—a malfunctioning AC affects driving visibility, and fogged-up windows make it dangerously hard to see the road. New drivers are advised to address such issues early, unlike me, who let it escalate. Regularly check for belt looseness as a simple preventive measure to avoid bigger troubles.

[CooperDella]

I usually figure out some car tips on my own, and it's not hard to tell if the compressor is bad. Start the car engine, turn the AC to max fan speed, and wait a few minutes to feel the air vent temperature. If it's not cold but rather warm, the compressor isn't starting, which indicates a high chance of failure. Then pop the hood and listen near the compressor location—abnormal noises like metal screeching often mean a bad bearing. Check if the compressor clutch is spinning; a loose or slipping belt can also cause issues. Last time my car had this problem, the repair shop diagnosed it as a refrigerant leak, and the compressor itself wasn't completely broken—just needed a seal replacement. Pay attention to these signs to avoid unnecessary major repairs. Safe driving is key, so always check the AC promptly if it fails.