Car Engine Overheating: Causes, Prevention, and What to do if car is overheating?

What are the causes of a car overheating?

​Radiator Issues That Cause Overheating

The radiator is the primary site of heat exchange for the entire cooling system. Any problem that impairs its function can cause the engine to overheat. Issues can range from external blockages to internal corrosion, all of which reduce the radiator’s ability to cool the fluid passing through it.

Proper radiator maintenance is essential to prevent overheating. Over time, debris, rust, and mineral deposits can accumulate, leading to problems that disrupt coolant flow and heat dissipation. A faulty radiator fan can also be a significant contributor to the engine overheating, leading to a rise in the engine temperature gauge.

Blockages and Restricted Coolant Flow

Internal blockages are a common radiator problem. Rust and sediment from the cooling system can build up inside the radiator’s narrow tubes, restricting the flow of coolant. This bottleneck effect means less coolant can be cooled, which causes the engine to overheat.

External blockages can also be an issue. Dirt, insects, and road debris can clog the radiator’s fins, preventing air from passing through and cooling the fluid inside. This reduces the radiator’s efficiency and can lead to a gradual increase in engine temperature, especially in stop-and-go traffic.

Damaged Radiator Fins

The thin metal fins on the radiator provide a large surface area for heat to dissipate into the air. If these fins are bent or damaged, airflow is obstructed, significantly reducing the radiator’s cooling capability. This can easily lead to an overheated engine during normal operation.

Damage to the fins can occur from road debris, pressure washing, or even minor front-end impacts. Carefully straightening bent fins can restore some efficiency, but extensive damage may require the radiator to be professionally serviced or replaced to keep your engine cool.

Faulty Radiator Fan

The radiator fan pulls air through the radiator, especially when the vehicle is stationary or moving at low speeds. Most modern cars use an electric fan that is controlled by a temperature sensor. If this fan fails to turn on, the engine will overheat in traffic or hot weather.

A faulty fan motor, a bad sensor, or a blown fuse can all cause the fan to stop working. If you notice your car is overheating in traffic but the temperature drops when you are moving at higher speeds, a malfunctioning radiator fan is a likely culprit.

The Impact of a Bad Thermostat

A bad thermostat is a relatively small and inexpensive part, but its failure can have severe consequences for your engine. Its job is to precisely regulate engine temperature by controlling coolant flow. When it fails, it disrupts this delicate balance, often leading to rapid overheating.

Because it is a common point of failure, the thermostat is one of the first components to check when a car is overheating. Understanding its failure modes can help you diagnose the problem accurately and prevent further damage to your engine.

Stuck Closed vs Stuck Open

A thermostat can fail in two ways it can get stuck open or stuck closed. If it sticks open, it allows coolant to flow continuously. This will cause the engine to take a very long time to reach its optimal operating temperature, leading to poor performance and fuel economy.

If the thermostat sticks closed, it prevents coolant from ever reaching the radiator. This is far more dangerous, as it traps heat within the engine, causing the engine to overheat very quickly. This scenario requires immediate action to avoid severe engine damage.

Symptoms of Thermostat Failure

The most obvious symptom of a thermostat stuck closed is a rapidly rising engine temperature gauge, often within minutes of starting the engine, indicating the engine is overheating. You might also notice coolant boiling in the reservoir or even leaking from the pressure cap as the system becomes over-pressurized.

Conversely, if the thermostat is stuck open, your car’s heater may not blow hot air, and your check engine light might illuminate due to the engine running too cool. Both situations indicate that the thermostat needs to be replaced to restore proper engine temperature regulation.

What to do if car is overheating?

Seeing the temperature gauge spike is stressful, but knowing what to do can prevent panic and minimize engine damage. If your car is overheating, your immediate actions are critical. The goal is to reduce the strain on the engine and allow it to cool down as safely and quickly as possible.

Driving an overheated car for even a short distance can cause irreparable harm, including a warped cylinder head or a cracked engine block. Following a clear set of steps will help you manage the situation effectively and protect your vehicle from the worst outcomes.

Immediate Steps to Take if Your Car is Overheating

The moment you notice your car overheating, take action. The first step is to reduce the load on the engine. Turn off the air conditioning immediately, as the AC compressor puts a significant strain on the engine, generating more heat.

Next, and this may seem counterintuitive, turn on your car’s heater and fan to the highest setting. The heater core acts like a small, secondary radiator, pulling heat away from the engine and releasing it into the cabin. This can help lower the engine temperature slightly.

Pull Over Safely and Turn Off the Engine

As soon as it is safe to do so, pull over to the side of the road and turn off the engine. An engine running, even at idle, continues to generate heat. Shutting it down stops this process and allows the engine to begin to cool.

Find a safe location away from traffic. Once parked, engage your emergency brake. This is the most important step to prevent further damage. Do not attempt to continue driving to your destination, as this will almost certainly lead to catastrophic engine failure.

Actions to Take After You Have Stopped

Patience is key once you have pulled over. Do not attempt to open the hood immediately. The cooling system is under extreme pressure, and opening the radiator cap can release a spray of boiling coolant and steam, causing severe burns.

Let the engine cool for at least 30 minutes, or until the temperature gauge returns to the normal range. Once the engine has cooled, you can safely open the hood to inspect for obvious issues like a broken belt or a major coolant leak.

Check the Coolant Reservoir

After the engine has cooled down completely, you can check the coolant level in the plastic coolant reservoir. If the level is low, you have likely found the primary reason for the engine to cool properly, preventing the car from overheating. You can add a 50/50 mix of coolant and water to the reservoir to bring it to the full line.

Never add coolant to a hot engine, as the temperature difference can crack the engine block. If you do not have coolant, water can be used in an emergency to get you to a repair shop, but the system should be flushed and refilled with the proper coolant mix as soon as possible.

Proactive Measures to Prevent Car Overheating

The best way to deal with an overheated engine is to prevent it from happening in the first place. Regular, proactive maintenance is the key to a reliable cooling system. Simple checks and timely service of the coolant system can save you from the stress and expense of a roadside breakdown caused by an overheating vehicle.

A few key habits, both in maintenance and driving, can significantly reduce the risk of your car overheating. Keeping an eye on fluids, inspecting components, and being mindful of how you drive will help keep your engine temperature in the safe zone.

Essential Cooling System Maintenance

Regularly check your coolant level. This simple check, which can be done when the engine is cool, is your first line of defense. Ensure the coolant in the reservoir is between the “min” and “max” lines. If you frequently need to add coolant, you have a leak that needs to be fixed.

Adhere to your vehicle manufacturer’s recommendation for a coolant flush. Over time, coolant loses its anti-corrosive properties, and contaminants can build up. A coolant flush removes the old fluid and any sediment, replacing it with new coolant to keep your engine protected.

Keeping Your Engine in Optimal Condition

Engine oil also helps transfer heat away from the engine. Therefore, maintaining the correct engine oil level is crucial. Low engine oil levels can contribute to overheating, as there is less fluid to absorb heat from the pistons and other moving parts.

Periodically inspect the cooling system’s hoses and the belts that drive the water pump. Look for cracks, bulges, or soft spots in the hoses. Check the belts for signs of fraying or glazing. Replacing these components before they fail can prevent a sudden and severe overheating event.

Driving Habits to Avoid Overheating

Be mindful of your driving, especially in hot weather or mountainous terrain. Avoid aggressive acceleration and high-speed driving for extended periods, as this puts additional strain on the engine and coolant system, increasing the risk of the engine overheating. Using a lower gear on steep inclines can also reduce engine load.

If you are stuck in heavy traffic on a hot day, consider shifting to neutral or park and revving the engine slightly. This increases the speed of the water pump and fan, improving coolant circulation and airflow through the radiator to help prevent the temperature from climbing.

Conclusion

Car engine overheating is often a symptom of poor lubrication. Using a high-quality engine oil is your first line of defense. Trust Armor Lubricants Supplier in UAE to provide the superior thermal stability and protection your engine needs to run cool and trouble-free.