What to Do If You Hear a Hissing Sound When Car AC is Turned On

December 30, 2023

If you hear a hissing sound when your car ac is turned on, it is important not to ignore the issue. The hissing noise could be a sign of an AC leak or a compressor problem. In either case, it is recommended that you seek professional assistance from an experienced mechanic to ensure that the problem is properly diagnosed and repaired.

There is a low-pressure side and a high-pressure side within your car AC system. When the system is running, the refrigerant (also known as freon) moves between these two sides to equalize the pressure. However, hissing sounds can be heard as the freon moves from the lower to the higher pressure side of the system.

A hissing sound can also be caused by a clogged compressor or air ducts in your car. This occurs when there are blockages or gaps in the air ducts that prevent the flow of cold air. In such cases, the hissing sound is caused by the escape of air from these openings under high pressure.

A hissing sound when your car ac system is on can also indicate that the compressor in your vehicle has a problem. The compressor is responsible for pressurizing the refrigerant within your car ac system. If there is a problem with the compressor, it may not be able to circulate the refrigerant through the system, leading to a loss of cooling performance. This could be due to a compressor leak, sensor malfunction, or other problems within the compressor.


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