Car Talk

Causes for Air Conditioner Breakdown in Summer

Avatar Adie Tinkle -

When driving on a hot summer day, the last thing you want is for your engine to overheat and your air conditioner breakdown. Overheating is one of the most prominent causes behind your AC to turn off. Most cars have safety features that turn off the AC when the engine gets overheated. Therefore, it is important to take immediate action when your engine overheats.

What Does “Engine Hot, AC Off” Mean?

The “Engine hot AC off” warning indicates that your car’s engine is at its maximum temperature and requires immediate attention. When the engine gets overheated, the system temporarily disables the AC to prevent further damage.

The “engine hot” light also turns on when the vehicle’s engine exceeds normal operating temperature, which can cause the onboard computer to turn off any system that puts more load on the engine, such as the AC system. This way, the vehicle’s system helps avoid potential engine overheating and costly repairs.

Possible Causes of Engine Overheating 

Overheating can occur as a result of many factors, including the malfunctioning of the cooling system, radiator, thermostat, or water pump. Below, we explore these reasons in more detail. 

Insufficient Coolant Level 

Running your vehicle on low coolant is a common cause of engine overheating. Insufficient coolant level obstructs the coolant system, leading to overheating. To manage this, you will have to add a coolant reservoir. Also, inspect the hose and radiator for leaks before refilling the coolant. 

Temperature Sensor Malfunctioning 

The temperature gauge is crucial as it shows when the engine starts to overheat. The temperature gauge receives the instructions from the temperature sensor. The breakage of the temperature sensor can result in incorrect reports and excessive heat that can cause permanent damage to your engine.

Heavy Load and High Ambient Temperature 

Operating your vehicle in hot temperatures, driving it for extended periods, or towing a trailer can put strain on the engine, hence increasing the risk of overheating. 

Overheating occurs when the engine does not cycle enough coolant through the cylinders and blockheads, which means that the heat cannot be transferred away from it. 

Blown Up Head Gasket 

A head gasket is a seal between the engine block and cylinder head. Its role is to keep the combustion gases in the cylinder and prevent engine oil and coolant from entering. An issue with the head gasket is difficult to diagnose because you will have to take the engine apart to identify it.

There are, however, other symptoms that can help you identify whether your head gasket is blown or not. They include engine overheating, white exhaust smoke, low coolant levels, and a strong, sweet smell of heated coolant. 

What Can You Do if the AC Turns Off Automatically?

Here are some of the things you can do with an overheating engine and air conditioner breakdown

Turn off the Engine and Pull Over 

As you notice the “engine hot AC off” warning, you should find a safe place and park your vehicle there. Turn off your engine so that it can cool down and you can save your vehicle from any damage. By turning off your car, high engine temperature stops safely.

Inspect for Leaks 

Look for signs of coolant leak, including puddles underneath the vehicle or steam from the engine bay. Leaks can cause coolant loss along with overheating issues.

Check Coolant Levels 

When your engine is cooled down, check the coolant level. If the level is low, it is possible that it caused your engine to overheat. Refill the coolant in accordance with the manufacturer’s recommendation. Before opening the radiator cap, wait for the engine to cool down. 

Call for Assistance 

If the issues continue and you are not sure how to proceed, it is preferable to contract a professional mechanic or get roadside assistance for further guidance. 

Can You Keep Driving with the Engine Hot AC Off Sign?

Air conditioner breakdown is due to overheating engine is a serious problem that must be addressed. Parking your car in the sun for too long and not maintaining it until the warning light comes on can cause you costly repairs.

The first thing you should do is pull over and evaluate the situation. It is preferable to turn off your engine because driving with an overheated engine can cause permanent damage to the engine.  

Check if the engine is overheating and consult a professional. If you are in a situation where you cannot stop your vehicle, then turn on the heat so that heat can be pulled from the engine bay. Also, roll down the windows so that heat can flow out of the vehicle. 

Importance of Regularly Maintaining Your Car 

Regular maintenance of your vehicle plays a significant role in preventing engine overheating. Here are some of the preventive measures you can take: 

Check Belts and Hoses 

Firstly, inspect belts and hoses for signs of cracks, as it can lead to coolant leaks and engine overheating.

Scheduled Servicing 

Following the service schedules for coolant flushes, engine maintenance, and radiator inspections is important. This will help ensure that your vehicle is running smoothly and prevent any potential issues down the road.

Monitor Coolant Levels 

Check the coolant level regularly and top up as needed to make sure that the cooling system is functioning properly. 

How to Prevent Your Vehicle from Overheating?

One of the best ways to ensure your engine’s safety is to check your vehicle’s coolant level. Low coolant can be the killer of overheating cars. Therefore, it is important to check the radiator and expansion take every now and then. What you can do is check the coolant level of your vehicle every time you fill up the gas, It will allow you to stay on top of the vehicle’s cooling system health. 

Also, pay attention to your car’s temperature gauge. Not keeping an eye on your car’s temperature gauge can cause it to overwear, and in no time, you will be looking for a new car. 

Lastly, ensure regular maintenance of your vehicle for it to work for many years. 


The Air Conditioner Breakdown warning is a very crucial safety feature that is designed to protect your engine from overheating. By understanding the causes behind engine overheating and by following safety measures to protect your engine’s health, you can easily prevent any potential breakdowns. Remember to maintain your vehicle regularly and reduce the risk of encountering this warning. 

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