What Causes the Abnormal Noise When Starting the Car Air Conditioning?
4 Answers
Here are several reasons for abnormal noise when starting the car air conditioning: 1. Noise from the dashboard: Usually caused by refrigerant expansion, or the presence of water or air in the refrigerant. Simply replacing the refrigerant can resolve this issue. 2. Excessive refrigerant: In this case, the owner needs to release some refrigerant appropriately. 3. Compressor: Long-term operation of the air conditioning may lead to aging of the compressor. Check if the compressor bearings or internal plungers need replacement. 4. Air conditioning filter: If the air conditioning filter hasn't been replaced for a long time, foreign objects may accumulate in the air ducts, causing abnormal noise. Additional information: If there is abnormal noise when the car air conditioning is turned on, it is recommended to visit a 4S shop for inspection first and then proceed with repairs after identifying the problem.
After driving for so many years, I've encountered quite a few cases of strange noises when the AC starts. The most common issue is a loose or worn compressor belt, which causes a squealing sound during operation, especially noticeable at startup. If the compressor bearings are damaged, you'll hear a grating metal friction noise that's quite unpleasant. Sometimes leaves or small stones get stuck in the fan area, creating a rustling sound when the wind blows, particularly noticeable when the AC is first turned on. Insufficient refrigerant or leaks can also cause noises as the compressor pressure becomes unstable, resulting in a low humming sound. I always make sure to regularly clean the fan vents and check belt tension. Small issues left unattended can turn into major problems - like a burned-out compressor that would cost a fortune to repair. So whenever you notice anything unusual, it's best to get it checked at a professional shop. Safety comes first, and strange noises while driving can be very distracting.
As someone who frequently repairs cars, I know that the causes of AC noise can vary widely. First, check if the compressor belt is loose or cracked – it tends to squeal upon startup, and an overly tight belt wears out faster. If the compressor's internal bearings are damaged, the operating sound resembles metal scraping, requiring prompt replacement. Foreign objects like leaves or paper scraps entering the blower fan can cause imbalance, resulting in a clattering noise, especially noticeable during startup. Refrigerant leaks leading to system pressure imbalance increase compressor load, making the noise louder. Poor contact in relays or switches may also produce clicking sounds. My advice: first identify the noise source – engine area issues point to belt/compressor problems, while air vent noises indicate fan issues. Regularly clean air ducts during maintenance to prevent worsening noises that could compromise driving safety. Often, minor repairs can resolve these issues.
I've been driving for several years, and the strange noise when the AC is first turned on has always been annoying. Common reasons in simple terms: dirt like dust or leaves stuck in the fan, causing a rustling sound when the wind blows; a loose compressor belt squeaks, especially noticeable at startup; insufficient refrigerant makes the system noisy; a damaged fan bearing produces a rattling sound. Last time, I encountered debris in the fan, and the noise disappeared after cleaning. If DIY is difficult, take it to a shop for inspection. Don't delay until it gets worse—persistent noise affects your mood and driving safety. Fixing it promptly saves a lot of hassle.
