What Causes the Abnormal Noise When Turning on the Air Conditioning in a Corolla?
1 Answers
Here are the reasons for the abnormal noise when turning on the air conditioning in a Corolla: 1. Fault phenomenon: When the air conditioning is turned on, abnormal noise comes from the engine area. There are mainly two reasons, which can be divided into two situations based on the different sounds of the abnormal noise: one is the metal friction sound emitted when the compressor electromagnetic clutch engages, and the other is the squeaking sound caused by excessive force on the air conditioning belt. Both of these situations occur only when the air conditioning is turned on and the accelerator is pressed. 2. Diagnostic analysis: When the compressor electromagnetic clutch engages and emits a metal friction sound, the fault is generally due to a lack of lubricating refrigerant oil inside the compressor. When there is insufficient refrigerant oil, the piston inside the compressor does not receive adequate lubrication during operation, resulting in a metal friction sound under the high pressure of the refrigerant. Another situation is a fault with the electromagnetic clutch itself, where the internal bearing is damaged and emits abnormal noise. 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, and then add the refrigerant. Start the car and run the air conditioning for a while to allow the refrigerant oil to circulate fully in the system. If the friction is severe, the compressor also needs to be replaced.