What Causes the Abnormal Noise When Turning on the Air Conditioning in a Mazda6?
3 Answers
Based on the different sounds of the abnormal noise, it can be divided into two situations: one is the metal friction sound emitted when the compressor electromagnetic clutch engages, and the other is the abnormal noise caused by excessive force on the air conditioning belt. The following are specific explanations: 1. Analysis one: The metal friction sound emitted when the compressor electromagnetic clutch engages 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. Analysis two: The abnormal noise from the air conditioning belt when turning on the air conditioning is caused by the rapid increase in the air conditioning system pressure when the air conditioning is turned on.
My old Mazda6 had the same issue last year! The AC would squeak as soon as it was turned on, and it turned out to be a failing compressor bearing. After seven or eight years of driving, the compressor is most prone to problems, especially when the AC is used for long periods in the summer—the noise becomes more noticeable. If you hear a metallic grinding or clicking sound, it's likely the bearing balls inside the compressor have worn out. I suggest not delaying; find some time to use a stethoscope against the compressor housing to pinpoint the noise. Also, have the mechanic check the belt tensioner and idler pulleys—these parts tend to age together, causing a chain reaction. It’s best to replace the entire set for durability. If the compressor fails completely, driving in hot weather will be miserable.
The issue of abnormal noise when the AC is on depends on the specific sound type. If it's a hissing sound like air leakage, it's most likely due to aging seals in the refrigerant pipes causing a Freon leak. My neighbor's Mazda6 had this problem last year, and the leakage point was found at the high-pressure pipe connection. If it's a metallic scraping sound, it's probably caused by leaves stuck in the blower fan blades. You can check by reaching behind the glove compartment to feel the blades. The most troublesome is a humming resonance sound, which is caused by aging rubber mounts of the AC bracket. This requires dismantling the dashboard to replace them. A quick tip: if you hear abnormal noise, first turn off the AC switch. If the noise disappears, it confirms the issue is with the AC system, avoiding misdiagnosis as engine noise.
