Why Does the Car Make Abnormal Noises When the Air Conditioner Is Turned On?
4 Answers
The reasons for abnormal noises when the car's air conditioner is turned on are as follows: 1. Air conditioning compressor failure. 2. Air conditioning belt slipping or wear. 3. Air conditioning pipeline blockage. 4. Electromagnetic clutch failure. 5. Foreign objects in the air conditioning vents. More information about car air conditioners is as follows: 1. The car air conditioning system is a device that cools, heats, ventilates, and purifies the air inside the compartment; it can provide a comfortable riding environment for passengers, reduce driver fatigue, and improve driving safety. 2. Cars widely use an integrated heating and cooling air conditioning system. Its layout involves assembling the evaporator, heater radiator, centrifugal blower, and control mechanism together, known as the air conditioning unit assembly.
When the air conditioning is turned on, there is an abnormal noise. My car had the same issue before, and the problem is usually due to an aging compressor or a loose belt. The compressor is like the heart of the air conditioning system; after prolonged use, worn bearings can produce a humming or grinding sound, while insufficient belt tension can cause a squeaking noise. Additionally, debris stuck in the fan blades or excessive dust buildup on the condenser can create imbalance and noise during operation. I suggest first identifying the sound: if it's coming from the engine compartment, it might be a fan issue; if it's under the cabin, it's likely due to evaporator icing or blocked air ducts. Promptly check the refrigerant pressure, as insufficient pressure can cause the system to freeze and produce a clicking sound. Ignoring abnormal noises may lead to compressor damage, which is more expensive to repair and can also increase fuel consumption. Take it to a professional shop for a technician to perform a pressure test and diagnosis. Small issues like replacing the belt or cleaning the system won't cost much but will ensure a quiet and cool driving experience.
Last time I turned on the AC, I heard a squeaking noise and suspected either the fan shroud was blocked by leaves or the belt was worn. After cleaning the filter and removing debris from the engine compartment, it improved slightly. It could also be due to insufficient coolant causing the expansion valve to freeze and make a clicking sound. Letting the car warm up for a few minutes before starting can reduce sudden load. If the noise persists, check the compressor clutch as a loose one can slip and increase noise. Recording the sound and taking it to the repair shop makes diagnosis easier. I regularly inspect the belt for cracks and check fan operation to avoid major repairs—driving in summer without AC is unbearable. Routine cleaning prevents most minor issues; don't let them escalate into fan burnout or refrigerant leaks, which are more troublesome.
Compressor bearing or clutch failure is the main cause of abnormal noise, producing harsh friction sounds. The evaporator freezing or expansion valve sticking can cause clicking noises. Aging and imbalance in the condenser fan motor lead to noise. Excessive moisture in the system or low refrigerant levels worsen freezing issues. Pressure testing and leak detection ensure accurate diagnosis. Timely replacement of aging components saves overall maintenance costs. Abnormal noises indicate potential failure risks, so early repairs are advisable.
