Why does the car make a squeaking sound when the air conditioning is turned on?

[SebastianFitz]

Compressor belt tensioner wheel damage; compressor malfunction; internal and external circulation motor failure. Diagnostic methods: 1. Lack of lubrication: When the compressor electromagnetic clutch engages, it produces a metal friction sound. The fault is usually due to a lack of lubricating refrigerant oil inside the compressor. When there is insufficient refrigerant oil, the internal piston of the compressor does not receive adequate lubrication, resulting in metal friction sounds under the high pressure of the refrigerant. 2. Electromagnetic clutch failure: Another scenario is a malfunction in the electromagnetic clutch itself, where the internal bearing is damaged and produces abnormal noises. In this case, the compressor must be replaced. If there is a lack of refrigerant oil, it is necessary to first recover the refrigerant from the air conditioning system, evacuate the system, refill with sufficient refrigerant oil, then recharge with refrigerant, and run the car with the air conditioning on for a while to allow the refrigerant oil to circulate fully through the system. 3. High pressure: The air conditioning belt makes abnormal noises when the air conditioning is turned on. This situation occurs when the air conditioning system pressure rises rapidly upon turning on the air conditioning.

[GraceMarie]

I've been driving for almost twenty years and have encountered the issue of squeaky air conditioning countless times. The most common cause is an aging or loose belt. When the engine drives the compressor, the belt slips and squeaks. Another possibility is worn bearings in the compressor itself, causing noise due to rough rotation. A leaf stuck in the fan motor or accumulated dust can also lead to squeaking. If a belt issue isn't repaired, it might snap and affect the air conditioning system, or even cause a dangerous breakdown on the road. You can pop the hood when parked to check for cracks or looseness in the belt, but it's best not to replace it yourself—a professional repair shop can diagnose it in minutes. During regular maintenance, ask the mechanic to pay extra attention to the belt's condition. It might need replacement around 30,000–40,000 kilometers—this isn't an expense to skimp on, as driving safety should always come first.

[FaithDella]

Using the air conditioning daily for commuting, I remember being quite alarmed the last time it made a squeaking noise. After consulting a friend, they said it's likely due to the AC drive belt wearing thin or becoming loose, causing friction when it can't turn the compressor properly. Another possibility is debris getting caught in the fan blades, causing unusual noises during rotation. Don't ignore such sounds; continuous squeaking could lead to the belt snapping, resulting in complete AC failure, which would be unbearable in summer. You can first try parking and checking the belt's condition under the hood—if there are no visible cracks, then seek help. During regular maintenance, remind the mechanic to check the belt tension. Proper maintenance can prevent about 90% of squeaking issues, saving you from worries on the road.

[VonSteven]

I'm a new driver, and the squeaking noise from the AC makes me nervous. My friend said it's often due to a loose or worn-out belt, which connects the engine and the compressor. When it's loose, it slips and makes noise. A faulty compressor bearing or something stuck in the fan can also cause such sounds. In this case, it's best to stop driving immediately and take it to a repair shop for diagnosis. It's not worth letting a small issue turn into a major repair. Getting it checked and fixed early ensures a safe and comfortable drive.