Why Your Car is Overheating While the A/C Is On? Possible Causes and Solutions

Why Your Car is Overheating While the A/C Is On? Possible Causes and Solutions

Did you experience that your engine overheats easily when your car’s air conditioning (A/C) is on? This is a very inconvenient situation, especially during summer. This will force you to shut off your A/C unit and be content driving with the windows down until you reach home.

Aside from the inconvenience that you may experience when this happens, the car’s engine is prone to serious damage. But this could be avoided when you know how to maintain your car. There’s got to be a problem in the system that needs to be addressed.

You may want to know the causes of this overheating and find out for yourself the possible solutions. For those not mechanically inclined, this may remain a mystery, not unless you know something. This article will explain to you why your car is overheating while the A/C is on.

What are the possible causes/solutions for overheating car?

These are some possible causes on why your car is overheating when you are in the middle of the road. The possible solutions are also explained:

  • Inefficient radiator

1. Leak on the radiator

Your car’s radiator acts as the cooling system for the engine. When you have a leak at the radiator, you will notice that the water in it is always drained even in short intervals. The radiator’s coils suffer corrosion over time and this may corrode the radiator parts, including the tubes.

​​Although the coolant that you are adding to the water has anti-corrosion properties, it becomes inefficient as years pass by.

One best alternative for coolant is the Prestone AF2100 Extended Life 50/50 Antifreeze by Prestone, available in Amazon.

Possible solution

You can test the leak by using or renting a coolant system pressure tester. It is a small pump that pressurizes the radiator system forcing the coolant on the weak spot (this would be the leak).

When you notice where the leak is coming from, it is better for you to bring the car to your trusted mechanic to do the fixing. Leaking coil or tube will be flared to seal the leak.

2. The build-up of dirt at the radiator’s coils and fins:

When you look at your radiator directly, you may see built-up debris or dirt in-between coils. This may entail overheating as air cannot pass through that cools the radiator.

The fins might be bent as a result of a bump by hard objects. This may also impede the air flow.

Possible solution

Clean up the dirt and debris by squirting pressurized water from a hose through the coil. You can bring back the fins in shape by carefully molding them using a flat-head screwdriver.

  • Radiator fan not working efficiently

Engine overheating may also be caused by an inefficient fan of the radiator.

Possible solution: Replace the timing belt, it might be worn out or loose that causes the fan to slip or to have a slower rotation.

  • Defective A/C compressor

The engine of your car also runs the A/C’s compressor. If the compressor is overloaded due to wear and other symptoms, the engine will have a problem rotating as the compressor adds up to its rotational load. Overheating is most likely to occur.

Possible solution: Let your mechanic do the check up on the compressor. However, some of the most common problems with compressors are a leaky seal and inadequate oil for lubrication.

  • Defective radiator water pump

This pump circulates the water (with coolant) inside the radiator system that keeps the engine from overheating. The rotation of the pump is accomplished by the drive belt run by the engine.

Possible solution: Conduct pressure testing on the cooling system for a possible leak. If the pump is defective, replace it with a new one. Fill the radiator with new coolant, new cap, and new thermostat (one best choice for the thermostat is the Beck Arnley Thermostat by Beck Arnley from Amazon).

Additionally, the best bet for a radiator water pump is the one with a brand name ​AC Delco’s 252-711 Professional Water Pump Kit available on Amazon, or one that has similar qualities.


Overheating car may be avoided if you use superior products like coolant, thermostat, water pump, and other accessories recommended by your car manufacturer. Plus good maintenance practices that you would do aside from the car’s recommended check-ups.

Please send to us your comments if you find this article interesting. We do hope to give you more of the hottest topics on car care in the near future.

About the author

Carolina - Care My Cars

Car, from a long time ago is the main transport vehicle for people which help to move faster and protect users from the unstable of weather such as sunlight, heat, or rainy. So that, the demand of car and the search for the best and a suitable car in the market are higher than ever and you also are one of the people who is looking for the answers from the market. Welcome to caremycars.com and I hope that my articles can help you to solve the problems that you are in with the most effective way. If you think my website give values, you can donate me by the ways. Donate: - Bitcoin (BTC): 1Eoz8vhfAjD4cCrq2jec3V38mmaHehedXU - Etherium (ETH): 0xd10809ae634117bf6c52Af884a8bc8B84D436e3b - BicoinCash (BCH): qqp4yjqx2g57exes0stsnkgk5e9uyu5clvrjj4ew44 Thank for all

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