What are the reasons for insufficient cooling in a sedan's air conditioning system?
2 Answers
There are several reasons why a car's air conditioning system may not cool effectively: 1. Damaged expansion valve: A faulty expansion valve prevents the formation of high pressure in the system before the valve, resulting in the high-pressure refrigerant failing to reach 150Kpa. This causes the evaporator behind the expansion valve to not cool down, leading to ineffective air conditioning. 2. Internal wear of the air conditioning compressor: Wear inside the compressor causes the pressure between the compressor and the expansion valve to not reach 150Kpa~200Kpa, preventing the refrigerant in the system from circulating normally and resulting in poor cooling. 3. Idle speed too low: An excessively low idle speed may lead the vehicle's computer to determine that turning on the air conditioning could cause the engine to stall.
The air conditioning in my sedan isn't cooling properly. After handling many similar cases, I've found the most common causes are insufficient refrigerant or leaks, which lead to low system pressure and poor cooling performance. Compressor failure is another major issue - if it's not running or making strange buzzing noises, cooling will fail. Condenser blockage from dust or insects obstructing airflow can reduce cooling efficiency. If the fan motor is broken and not spinning, lack of air circulation will also affect cooling. A dirty cabin air filter restricts airflow, so regular replacement is recommended to maintain proper ventilation. Some electrical issues like short circuits or sensor malfunctions may also cause problems, requiring professional diagnostic equipment. Generally, start with simple checks like inspecting the filter and fan operation yourself. If that doesn't help, promptly visit a repair shop for thorough diagnosis to avoid discomfort during summer driving.
