There is little good that comes from being stuck in a car without an air conditioner (AC) in the heat of summer. But what if your car starts overheating every time you activate the AC?
It can be more than just an annoyance, leading to significant damage to your engine if left unaddressed.
In this post, we’ll delve into why your car overheats when AC is on and offer some solutions that can help keep you on the road.
Topic Summary
What Causes Car Overheats When AC is On
If you turn on the AC while on the road, in order to power the AC compressor, your engine needs to work harder, which can produce more additional heat.
And if your car’s cooling system is already weak (for instance, its fans are blocked in some way), that extra burden will then be too much for it, and the engine will overheat. Here’s some more detail about the causes of this situation.
Coolant Level Too Low
Coolant, also called antifreeze, is required to keep your engine from overheating; too little of this fluid means the substance needed to absorb and evaporate those harmful byproducts of AC, and your vehicle’s engine does not have enough areas to attract their intense heat.
Faulty Radiator
The radiator removes heat from the coolant. If it’s plugged up or defective, it won’t cool the coolant properly, leading to overheating of the engine.
Worn or Broken Water Pump
The water pump circulates coolant around the engine. If it’s not working properly, the coolant system’s flow will be restricted, and your engine will overheat.
Defective Thermostat
The thermostat opens and closes to allow coolant to flow depending on the engine’s Temperature. Can your vehicle make it up a hill with the thermostat stuck closed so the coolant doesn’t circulate properly? The answer will be no because your engine will overheat.
Bad Fan
Fails to remove heat from the coolant by drawing forced air through the radiator. This may lead to the engine overheating from lack of cooling.
Condenser Issues
The radiator-facing AC condenser expels the heat absorbed by the refrigerant. If it’s plugged up or has septic leaks, that energy won’t escape properly, and your engine will overheat.
Diagnosing and Fixing the Problem
To address the issue, follow these steps:
Check on your coolant level
Check to see if you have the correct amount of coolant. If you are low, add the proper mixture of coolant and water (typically a 50/50 mix) and top it off. If your coolant level drops frequently, there may be a leak in the system.
Check the Radiator
Check the radiator for signs of blockage or damage. Consider a professional radiator flush, or replace it if damaged.
Water Pump
Listen for a squealing noise caused by a failing water pump. Look for coolant leaking around the base of the pump. Have it inspected. If necessary, have it changed.
Try the Thermostat
You can remove it and test it in hot water to see if it opens. If not, replace.
Radiator Fan
Make sure the fan comes on when the engine gets hot, particularly with the AC on. If not, the fan motor or the fan relay would be suspect.
Clean or Replace the Condenser
If you find dirt blocking the condenser unit, clean it off. If the coils are damaged or clogged completely, the condenser needs to be replaced. You can clean the drain pipe with soap and water.
Measures for Car Overheats When AC is On
Routine maintenance: Regular maintenance, such as coolant flushes, radiator inspections, and AC checks, is recommended to avoid overheating.
Watch Your Temperature Gauge: Check your car’s temperature gauge, especially when driving with the AC on. If it begins to rise, shut off the AC and determine the problem.
Use Quality Coolant: Always use the coolant recommended by your vehicle’s manufacturer.
Keep an Eye Out for Leaks: Under your car is a good place to look for leaks from coolant, especially if the weather is hot or you’ve been on a long journey.
Knowing why your car is liable to overheat when the ACs are on can help you drive better, take the right precautions, or at least enable you to drive safely when it happens.
Understanding the underlying cause of car engine overheating can help you plan your trips and keep you out of trouble, provided you don’t rely too much on the AC and adapt accordingly. Driving your vehicle in extreme weather conditions could potentially worsen the problem.
If you don’t feel qualified to diagnose or fix any of these problems, your best bet will be to get it checked out by an expert. You don’t want to drive your car until it stops moving entirely, only to be told that you could have prevented hundreds of dollars worth of damages.
FAQs On Car Overheats When AC is On
Why does my car overheat when I turn on the AC?
There are many reasons why the AC might be causing your car to overheat, including a high engine load, a failing cooling system (from low coolant levels to a faulty cooling thermostat), radiator fan problems, and problems related to the AC system itself. The AC compressor load further strains any existing cooling-related issues.
What to look at when car overheats with AC on?
Check that the coolant levels are topped up, there are no blockages in the radiator or leaks in the system, and that the radiator fan is working. Also, check the thermostat for correct operation. If all seems well, just take the car to a licensed mechanic who can check the AC system.
Can a dirty condenser cause my car to overheat?
Yes. If the condenser is dirty or blocked, the flow of air will be restricted, and less cooling will be established. The impact of that will be the engine overheating when the air conditioning is switched on. If the condenser is regularly cleaned, then this will not happen.
Can I drive my car if it overheats when air conditioning is turned on?
If your car overheats, even if it only happens when you have the AC on, DO NOT drive any further, no matter how close you are to your destination. This is extremely serious and will damage the engine. If you’re overheating, turn the AC off and wait for the engine to cool completely so that you can have it serviced and fixed as soon as possible.
How to prevent car from overheating when using AC?
Inspect your cooling system, including coolant levels, radiator condition, and the workings of the radiator fan and thermostat, regularly to ensure your car doesn’t overheat. Keep the condenser clean and check the air-conditioning system to ensure it operates smoothly. Follow the car maintenance schedule and have the issues rectified promptly to keep your engine cool even when your AC is turned on.
Conclusion
Car Overheats When AC is on could be annoying, knowing what we know -and taking the appropriate measures- we could not only clear the surface but rectify the situation.
Necessary maintenance is vital for the car to both last longer and perform in whatever the weather happens to be. Timely repairs also play a role in the life of the owner, coming in handy, especially when it starts to heat up. God bless! If in doubt, do not hesitate to call the mechanic.
If you get in front of things, you shouldn’t have to endure the heat from overdriven fluids when what you really want is a cool and breezy ride.