Will Running the AC Cause An Engine to Run Hotter?
When running your car or truck’s air conditioning system during hot weather you may notice the engine idles faster and the engine fan runs louder. The engine fan will operate at a higher speed to reduce the extra engine heat generated.
Like a home air conditioner, your car ‘s AC uses a compressor. The compressor works with a clutch and is regulated by high and low pressure sensors that cause it to turn off and on. Every time it cycles on it creates more strain on the engine, generating heat. In addition, the engine’s serpentine belt drives the AC compressor, which also takes more energy from the engine.
So yes, running your air conditioner during hot weather will cause the engine to run hotter. This should not be a problem under normal conditions. However, if the AC cycles on and off continuously, it could mean the refrigerant levels are too low or there is something else wrong. If you notice the engine temperature climbing higher than normal when the AC is off, it can be a sign of a problem with the cooling system.
You may also notice a slight decrease in performance and fuel economy when the air conditioning is running. This is normal and simply a side effect of the extra energy needed by the engine to power the AC.
