Why does the engine sound louder when the air conditioner is turned on?
2 Answers
When the air conditioner's cooling function is activated, the engine needs to drive the compressor, causing the idle speed to increase and the engine sound to become louder. This is a normal phenomenon. The function of a car air conditioner is to regulate and control the temperature, humidity, air cleanliness, and airflow inside the vehicle to an optimal state according to the set temperature, providing a comfortable riding environment for passengers and reducing travel fatigue. The method of using the air conditioner is: 1. After starting the vehicle, turn the air conditioning knob to the cooling or heating zone; 2. Press the AC button when cooling is needed.
When it comes to the engine noise becoming louder when the air conditioning is on, I think it's quite common, especially during hot summer driving scenarios. When the compressor starts, it requires additional power from the engine to provide cooling, which suddenly increases the engine load. Naturally, the engine speed rises, and the sound becomes louder. The fan system also operates at high speed to dissipate heat, which can generate significant noise as well. Normally, it's a steady humming sound, but if you hear squealing or clunking noises, it might indicate a loose belt or an issue with the compressor bearing. I used to notice this particularly in older cars because carbon buildup made the engine struggle more under load. Regularly checking the belt tension and the compressor's operation is important to avoid more serious engine issues later on and to maintain driving comfort and safety. If you're concerned, you can lightly press the accelerator after turning on the AC to listen for any unusual changes in the sound to determine if there's an abnormality.
