Skip the auto shop - Our mechanics make house calls

Q: Does Running My AC in the Summer Keep My Engine Cooler?

asked by on

Does running my AC in the summer keep my engine cooler?

Automotive air conditioning (AC) will cause the engine to run hotter in the summer because it creates more heat in the engine compartment and there will be more strain on the engine to operate the AC compressor. The AC compressor works with a clutch - kind of like a standard transmission - but it is magnetic and is regulated with different high and low pressure sensors that cause it to cycle off and on. Every time it cycles on it creates more strain on the engine and in turn will create heat. If the AC cycles on and off continuously, you have issues with either low refrigerant levels or something else wrong in the system. The engine’s serpentine belt drives the AC compressor, which requires more energy from the engine. You may actually notice a slight decrease in performance and fuel economy when the air conditioning is engaged.

When the AC is running, you’ll likely hear the engine fan running louder if you do not have electric fans. Either the fan operates at a higher speed to combat the extra engine heat generated, or there may be a secondary electric air conditioning fan that runs when the AC is turned on to provide extra cooling. It is turned on by the cooling fan module or a body control computer that will command the relay to operate.

If you notice the engine temperature climbing higher than normal when the air conditioning is off, it can be a sign of a problem with the cooling system. If the engine runs hotter than normal with the AC turned on, there could be an issue with the AC electric cooling fan. If you have issues with the vehicle overheating in the city but not on the highway, this is a fan issue, meaning the fans are not operating. You actually could turn the AC on to help cool down the engine if the electric engine fan is not working. However, in order for this to work your vehicle would have to be equipped with two electronic cooling fans. You should have your vehicle checked by an experienced technician.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My car won't start

Hi there, from the symptoms you have described, it sounds more like a fuel issue. Either the fuel pump is failing and not pumping enough fuel into the engine, or some component such as a coolant temp sensor or fuel...

Q: My air doesn't work all the time

Hello, thank you for writing in. There are a few more bits of information that we need to try and help guide you. If by not having air, you mean that the air stops blowing, then you have an issue...

Q: My engine fan is not kicking in, but my temp is between 80 -100. Is my thermostat bad because my check engine light just turned on

This can be caused by a number of things such a faulty thermostat, or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...