What Causes Loud Engine Noise When the Air Conditioner is On?
2 Answers
The reason for loud engine noise when the air conditioner is on is: After activating the air conditioner's cooling function, the engine needs to drive the compressor to operate, which increases the engine's idle speed and results in louder engine noise—this is a normal phenomenon. The function of a car air conditioner is: to regulate the temperature according to the set level, maintaining the cabin's temperature, humidity, air cleanliness, and airflow in optimal conditions, providing a comfortable environment for passengers and reducing travel fatigue. The method for using the air conditioner is: 1. After starting the vehicle, turn the air conditioner knob to the cooling or heating zone; 2. Press the AC button for cooling.
I've also experienced the issue of significantly increased engine noise when turning on the air conditioning while driving. The main reason is that when the AC is activated, the engine needs to additionally power the compressor, which increases the load and raises the RPM, making the existing noise more noticeable. For example, worn compressor bearings or aged/loose belts may produce sharp squealing sounds during operation. The cooling fan might also operate at high speeds with noticeable noise, especially when dust accumulation reduces fan blade efficiency. Another factor could be poor engine condition itself - such as excessive carbon buildup or insufficient engine oil under heavy load. It's also possible that soundproofing materials have degraded. I recommend starting with simple checks: inspect whether belts are cracked or if the fan is clean. If that doesn't resolve it, then examine the compressor and engine components for necessary repairs to maintain driving comfort and safety. This issue occurs frequently in summer, and neglecting it may lead to more serious failures like belt breakage affecting vehicle operation.
