What Causes Abnormal Noises When the Car Air Conditioner is On?
4 Answers
The air conditioning system adjusts and controls the temperature, humidity, air cleanliness, and airflow inside the car cabin to a suitable state, providing a comfortable environment for passengers, reducing fatigue during travel, and creating favorable working conditions for the driver. It is a crucial ventilation device for ensuring safe driving. The reasons for abnormal noises when the car air conditioner is on include: 1. Damaged compressor belt tensioner; 2. Excessive wear or damage to the blower motor; 3. Malfunction of the air recirculation motor; 4. High pressure in the air conditioning system; 5. Incomplete engagement of the compressor clutch; 6. Prolonged non-replacement of the air filter. Solutions for abnormal noises when the car air conditioner is on: 1. Clean the air conditioner vents promptly; 2. Remove the fan blades to add lubricant and clear any foreign objects; 3. Replace the blower with a new one; 4. Replace the air filter.
I've been driving for over twenty years, and it's quite common to encounter strange noises when the air conditioning is turned on. The main culprits are dust buildup inside the blower fan or leaves and insects getting stuck, causing a buzzing sound like a small fan is broken. A loose or slipping belt will squeal, especially noticeable during acceleration. If the compressor is faulty, there will be a clicking sound, which can be quite alarming. Worn bearings inside the compressor or poor refrigerant flow can also increase noise, and a gurgling water sound might indicate a clogged evaporator. Don't underestimate these noises—the longer you ignore them, the more expensive the repairs will be. Replacing the entire compressor can cost thousands. I think it's a good idea to clean the fan screen and filter before summer. Using a small brush to remove dust is quite simple and saves the hassle of going to the repair shop, keeping the car quiet and comfortable during drives.
As an amateur car enthusiast who has been tinkering with repairs for several years, I've found that most air conditioning noises are caused by foreign objects stuck in the blower fan blades creating imbalance, resulting in annoying buzzing sounds. Worn or loose belts produce squeaky friction noises, while compressor knocking sounds often indicate clutch or bearing issues. Loose refrigerant pipes can also cause resonance noises. Different sounds correspond to different problems: whooshing indicates fan issues, squeaking points to belt problems. I recommend identifying the approximate location by ear, but professional tools are needed to inspect the compressor. Replacing fan blades yourself costs just tens of RMB, and loose belts can be tightened. Compressor issues require expensive complete system repairs - fixing early prevents major overhauls. Regular filter cleaning and seasonal maintenance can prevent noises, which I always prioritize in my routine maintenance.
My car's AC keeps buzzing when turned on, and the inspection showed the fan is heavily clogged with dust. It also makes scary rattling noises when the belt is loose or the compressor is about to fail. A loud water-like sound is common when the refrigerant flow is obstructed. Don't ignore these noises—delaying repairs can lead to worse part failures. It's safer to visit a repair shop to avoid breaking down halfway on the road.
