What causes the sound of water flow near the engine when the air conditioning is turned on?

[VanNathan]

When you hear a water sound from the car with the air conditioning on, it's because the condensate water from the air conditioning system drains out of the cabin through hoses. It is recommended to check the central air conditioning hoses, coolant, outdoor unit, and filter screen. Inspect whether the central air conditioning hose has come loose. If not, the sound is likely caused by the refrigerant flowing and evaporating inside the compressor, which is a normal phenomenon. If the water sound is produced when water passes through the heater core, it is advisable to check if the engine coolant is low. In such cases, you can first add antifreeze, then press the accelerator a couple of times to let the engine rev up and expel air from the system. Check the outdoor unit of the car's air conditioning for any obstructions. If present, clear them promptly. Inspect the air conditioning filter screen. Open the indoor unit cover to check for dust or odors on the filter. If excessive dust or severe odors are found, clean the filter screen.