What are the reasons for insufficient cooling in a sedan's air conditioning system?

[GideonAnn]

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.

[FranciscoRose]

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.

[JourneyDella]

I've been driving a sedan for over ten years, and it's quite frustrating when the air conditioning doesn't cool properly. Common causes include refrigerant leaks or insufficient pressure requiring Freon recharge, which are basic issues. If the compressor is severely worn, stuck, or making unusual noises, the entire system can fail. Dust accumulation on the condenser fins or blockage by debris can impair heat dissipation, preventing cold air from coming out. A faulty fan motor that doesn't blow air directly affects airflow circulation. A dirty air filter that hasn't been replaced for a long time can obstruct air passage and reduce cooling efficiency. Last time, my car lost cooling due to a refrigerant leak, but it returned to normal after a refill. As a reminder, regularly check the airflow from the air conditioning vents during daily driving. If you notice a decrease in airflow, promptly inspect the filter or refrigerant to prevent minor issues from escalating. Getting a pre-summer maintenance check can save a lot of hassle.

[CarlosMarie]

Poor air conditioning cooling can often be resolved with simple fixes. Insufficient refrigerant is the most common issue—try adding refrigerant. If the compressor is faulty, weak rotation leads to poor cooling. A dirty condenser can be cleaned to restore heat dissipation. Check if the fan motor is burnt out if it's not spinning. Replacing a clogged filter improves airflow. A faulty control module may misread temperatures. It's recommended to first check the filter and refrigerant yourself. If DIY skills are limited, visit a professional shop for tool-assisted diagnostics to avoid overheating issues on the road.