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

When you engage your air conditioning in your car, it is usually summertime and hot outside. Air conditioning serves to remove heat from the inside of your vehicle by circulating a refrigerant through the evaporator core in your dashboard, and blowing the cooled air into the cabin with the blower motor. Many people believe that air conditioning also cools your engine when it is engaged but the opposite is true.

How air conditioning affects your engine

Air conditioning actually creates more engine heat in the engine compartment as there is more strain on the engine to operate the AC compressor. 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. Either the fan operates at a higher speed to combat the extra engine heat generated, or there may be a secondary air conditioning fan that runs to provide extra cooling. It is triggered by the cooling fan module or resistor to operate when the air conditioning is turned on.

If you notice the engine temperature climbing higher than normal when the air conditioning is turned on, it can be a sign of a problem with the cooling fan or the AC cooling fan. Have your car checked out if you experience higher than normal engine temperatures.


Next Step

Schedule Cooling Fan Relay Replacement

The most popular service booked by readers of this article is Cooling Fan Relay Replacement. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Cooling Fan Relay Replacement reviews

Excellent Rating

(36)

Rating Summary
32
1
1
0
2
32
1
1
0
2

Peter

43 years of experience
1321 reviews
Peter
43 years of experience
Chevrolet Silverado 1500 V8-5.3L - Cooling Fan Relay - Phoenix, Arizona
Was very professional, punctual and is very knowledgeable. He did a great job working on my truck.
Jeep Grand Cherokee - Cooling Fan Relay - Surprise, Arizona
was pleased with my first experience with your company.

Shawn

12 years of experience
285 reviews
Shawn
12 years of experience
Volkswagen Jetta L4-2.0L - Cooling Fan Relay - Lancaster, Pennsylvania
Shawn was professional, knowledgeable, and was able to fix my car within a timely manner. Will be using services again! Thanks Shawn.

Patrick

33 years of experience
1408 reviews
Patrick
33 years of experience
Jeep Grand Cherokee L6-4.0L - Cooling Fan Relay - Austin, Texas
Patrick is always knowledgeable and professional and never tries to charge me for anything I don't need. I have a nineteen year old Jeep that I love, and Patrick takes excellent care of her, and I trust him implicitly to keep her running smoothly! He's truly invaluable!

Ernesto

32 years of experience
28 reviews
Ernesto
32 years of experience
Toyota Highlander V6-3.3L - Cooling Fan Relay - New Berlin, Wisconsin
Ernesto repaired my car in a timely fashion. He was knowledgeable, communicated what was going on with the car and has a pleasant personality. Thank you Ernesto!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How to Replace an AC Condenser Fan
AC condenser fans need to be replaced when the air conditioning stops running. If the AC fans don't work when the car is on, the fan relay may be bad.
How to Replace an AC Evaporator Sensor
The air conditioning pressure evaporator sensor monitors and adapts to the evaporator's temperature, preventing damage and keeping the AC working.
How to Replace a Radiator Fan Motor on Most Cars
The fan motor on the radiator fails when the engine overheats and the fan does not activate. This means that the coolant cannot cool the engine well.

Related questions

Rattling in engine when first starting
Honda has a service bulletin out for this specific complaint of a rattling noise of the engine during warm up. The bulletin number is 07-028 and it refers to having an intermediate heat shield replaced with an updated part as...
My heat and AC do not work - 2003 Volkswagen Beetle
It sounds like the blend door may be stuck. The blend door is usually controlled by a cable or an actuator. If the switch itself seems to be hard to turn, it is likely cable driven and experiencing a restriction....
AC not working for 2015 Honda accord sport
Hello, thank you for writing in. Considering the age of the vehicle, it may be under warranty. It is absolutely worth looking into. Only the dealer will be able to answer that question for you depending on your specific agreement...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com