Why does the engine make a whining sound when accelerating with the AC on?

[StEmerson]

The detailed reasons for abnormal noises when accelerating with the AC on are as follows: 1. Caused by compressor damage: The electromagnetic clutch of the AC compressor may be slipping, or the internal bearings may be worn due to prolonged use. 2. Due to collisions during daily vehicle use: Or when replacing components such as the electric fan, radiator, or condenser, improper installation during repairs—such as mismatched part sizes, differences in rubber bushings, or improper alignment of the radiator and condenser frame—can cause body resonance when the electric fan operates with the AC on, leading to abnormal noises during acceleration. 3. Due to issues with the AC system pressure: If the radiator or condenser surface is excessively dirty, heat dissipation efficiency decreases. Poor heat dissipation after turning on the AC increases pressure in the pipes, causing the electric fan to operate at high speed and produce abnormal noises. Alternatively, overcharging the system with refrigerant can cause the system pressure to rise when accelerating with the AC on, leading to high-speed operation of the electric fan and resulting in abnormal noises.