Why does the air conditioning cool when stepping on the accelerator but not when not stepping on it?
2 Answers
The reasons why the air conditioning cools when stepping on the accelerator but not when not stepping on it: 1. Poor heat dissipation of the condenser: You can clean the condenser with water when washing the car or take it to a quick repair shop to blow the condenser with an air pressure gun, and also check the refrigerant pressure. 2. Excessive refrigerant: When the accelerator is pressed, the compressor speed increases, and the high pressure rises. Due to excessive refrigerant, the high pressure becomes too high, causing the high pressure protection switch to trip and stop cooling. Conversely, when driving at low speeds, the high pressure is normal and not too high to trigger the high pressure protection, allowing the compressor to cool normally. 3. Excessive dirt in the refrigeration oil: This can clog the filter screen of the filter, reducing the cooling effect, increasing resistance, and decreasing the flow of refrigerant to the expansion valve, leading to the car air conditioning not cooling. Sometimes, if air enters the car air conditioning system, it can cause excessive pressure in the refrigerant pipes, and poor refrigerant circulation can also lead to insufficient cooling.
Having driven for over twenty years, I've encountered quite a few air conditioning issues. When you step on the gas pedal, the AC cools better because the engine speed increases, making the compressor belt spin faster. This pumps the refrigerant more vigorously, naturally improving the cooling effect. When not accelerating, the engine idles at a lower speed, causing the compressor to work sluggishly, resulting in weaker cooling—especially during summer traffic jams when the AC seems barely on and wastes fuel. During a repair visit, the mechanic told me this is quite common. It's essential to regularly check if the belt is loose or worn out, and the compressor clutch might also be worn, causing idle malfunction. For peace of mind, inspect the AC system before long trips, or consider switching to electrically driven auxiliary systems. Some new car designs can help minimize this issue.
