What causes the buzzing sound when the Audi A4's air conditioning is turned on?
2 Answers
Reasons for abnormal noise when the car's air conditioning is turned on include: damaged compressor belt tensioner, excessively worn or damaged blower motor, malfunctioning internal/external circulation motor, high air conditioning system pressure, improper engagement of the compressor clutch, and prolonged non-replacement of the cabin air filter. Below are more related solutions: Solutions for abnormal noise when the car's air conditioning is turned on: 1. Clean the air conditioning vents promptly. 2. Remove the fan blades to add lubricating oil and clear any foreign objects. 3. Replace the blower with a new one. 4. Replace the cabin air filter. The air conditioning system adjusts and controls the temperature, humidity, air cleanliness, and airflow inside the car cabin to a suitable state, providing passengers with a comfortable riding environment, reducing fatigue during travel, creating favorable working conditions for the driver, and serving as a crucial ventilation device for ensuring safe driving.
I recently researched the issue of abnormal noises in the Audi A4's air conditioning system. The humming sound can be categorized into several scenarios: Low-frequency vibrations when the compressor starts up are normal, but if accompanied by steering wheel shaking, the engine mounts should be checked. Additionally, a continuous buzzing sound could indicate aging of the AC belt or worn tensioner pulley bearings, while overcharged refrigerant can also cause abnormal compressor noise. Once I found tree leaves stuck in the blower fan blades creating similar sounds - I recommend switching to recirculation mode first to locate the noise source. If cooling performance is normal, focus on checking for deformed radiator fan blades - Audi's fans are particularly prone to heat-induced deformation causing contact with the frame. Don't rush to replace the compressor; most cases involve pipe vibrations or loose mounting clips. Testing by wrapping high-pressure pipes with foam tape might solve the problem.
