What Causes a Car To Overheat?
May 20, 2023

I am a serial entrepreneur and a consumer advocate. When I’m not helping car buyers, I love working on ventures that have a positive impact.
I run a cause marketing agency and serve on the board of Vayu Global Health where we are disrupting the medical industry and preventing the needless deaths of mothers and babies during childbirth.
As a car owner, one of the various car-related problems you don't ever want to encounter is engine overheating. It can be incredibly frustrating, especially when it happens to you the first time. But what causes a car to overheat?
You must identify the source of the problem to prevent expensive repairs and further damage.
Overheating may happen even with the usual upkeep. Automobiles are complicated devices with many different pieces running together for correct performance.
Various issues, from low coolant to a damaged cooling system, can result in overheating.
Knowing the sources of overheating helps preserve the wellness and endurance of an automobile. It also helps prevent potential safety risks on the street. Keep reading to find out what causes a car to overheat and how to prevent this issue.
Table of Contents
How the Car Engines Work
Vehicles need a power source that propels them forward, and the car engine serves as this source. The engines convert fuel into energy, which helps to drive the car's varying systems.
Understanding how car engines work is essential for any motorist who wants to preserve their vehicle and maximize its performance.
First, car engines are internal combustion engines. So, they depend son the principles of the internal combustion. They run by igniting a fuel-air mixture in a combustion chamber to produce energy.
The most common type of car engine is the four-stroke engine. It has four major components: the intake, compression, combustion, and exhaust.
The intake is the first phase, where the engine draws in air and fuel. The intake manifold distributes the air-fuel combination to each engine's cylinders.
After the air-fuel mixture goes inside the cylinder, it squeezes the piston in the second step, compression. Compression activates energy in the subsequent stage.
The combustion process is where the real action happens. In this phase, the spark plug ignites the air-fuel blend, causing it to burst and create energy. The energy is then passed on to the engine's crankshaft, transforming it into rotational energy.
The exhaust is the last stage. The engine emits waste products. This is done by the exhaust manifold channeling the gases out of the engine and into the exhaust system.
Additional components of the car engine, like the camshaft, govern the opening and end of the engine valves. The oil pump disperses oil around the engine for lubrication.
The engine's cooling system is also important. It keeps the engine from overheating by circulating coolant.
What Causes a Car to Overheat?
The following are the most common causes of overheating in cars:
1. Low Coolant Levels: A Common Culprit of Overheating
A common cause of an overheating engine is low levels of antifreeze, or coolant, which circulates to absorb heat. Insufficient liquid implies cannot take away heat, thereby causing overheating.
Check coolant levels regularly and top them up if necessary to protect the engine from harm.
2. The Thermostat: How It Can Cause Overheating
The car's cooling system's thermostat dictates how fluid can circulate between the engine and the radiator.
If it stays impersonally closed before the motor reaches its optimal heat, the coolant cannot travel to the radiator.
After the engine reaches its designated temperature, the thermostat opens. It allows the liquid to go to the radiator, cool it off, and return to the power plant.
The motor will quickly overheat if the thermostat freezes or can't correctly open. It won't be able to receive its coolant as the transfer of liquid is barred. This causes the engine to become too hot. It can lead to serious harm, like expensive engine and hardware repairs.
When the thermostat fails to close, the engine does not warm up adequately, which leads to lower gas mileage, declined capability, and increased pollutants.
Replacing a defective thermostat protects the engine from hefty damages and keeps your vehicle functioning optimally.
3. Water Pump Failure: A Common Cause of Overheating
The water pump regulates the engine’s warmth. It circulates coolant through the engine. However, equipment like the impeller and seal can become worn down over time, resulting in a lack of performance or total failure.
If that happens, then the coolant does not circulate effectively, leading to overheating. It can consequently damage the engine and other parts, causing expensive repairs.
4. Radiator Issues: How They Can Cause Overheating
The radiator prevents engine overheating. Malfunctions of the radiator can lead to the engine getting too hot.
Common abnormalities associated with the radiator include clogging, leaks, and destruction of the tubes/fins. Scheduled upkeep and investigation of the radiator help avoid excessive warming and expand the motor's life.
5. Other Causes of Overheating: Electrical Issues, Cooling Fan Malfunctions, and More
Various issues may cause an automobile's engine to overheat, including electrical complications, cooling fan failures, etc.
The automobile's computer might misperceive the temperature when the temperature sensor is faulty, leading to the engine overheating.
When the cooling fan does not work correctly, air may not circulate the radiator, leading to overheating.
Other potential causes are obstructed hoses or a defective head gasket. Taking accurate measures and regularly inspecting the vehicle's cooling system ensures the engine functions properly.
What Happens When a Car Overheats?
Engine overheating poses serious dangers.
It can lead to the following damages:
1. Engine component damage
It can lead to damage to engine components. For example, warped cylinder heads, require an entire engine replacement. Seals and gaskets may also be affected due to leaks of oil and coolant, incurring further damage and pricey repairs.
More distressingly, overheating can cause a blown head gasket. That’s when coolant seeps into the engine's cylinders and misfires. This could stall the engine.
2. Transmission issues
The transmission depends on the engine's cooling system to regulate its temperature. Overheating can compromise the transmission, damaging the transmission fluid and, consequently, failure.
3. Poor handling
Overheated cars may be difficult to handle. They often suffer poor braking ability, thus posing a severe risk in heavy traffic or on slopes.
4. Fume emission
The car might emit harmful fumes, potentially placing the people in hazardous conditions. In a worst-case scenario, the car may even combust, instigating a more significant danger if parked near other vehicles or in a garage.
The coolant level, temperature gauge, and cooling system require a consistent inspection to reduce the likelihood of overheating.
Moreover, the engine should be well-rested in hot weather or traveling steep hills.
Understanding the Cooling System
The cooling mechanism of a car is a fundamental aspect of its functioning.
The cooling system has many components including the radiator, water pump, thermostat, and fan.
The radiator sits toward the front of the car, right behind the grille, and is the visible part. It is accountable for dumping heat generated by the engine. It allows the passage of coolant over many fins that let air pass over them, thus cooling the fluid.
The belt drives the water pump linked to the engine's crankshaft. It flows the coolant through the engine, guaranteeing that every component is chilled.
The thermostat is another essential portion of the cooling set-up. It’s between the engine and the radiator. It controlls the current of coolant over the engine by opening and closing a valve based on the engine’s temperature.
The fan is the last component of the cooling system. It pulls air over the radiator and the engine, usually powered by electricity. It switches on and off, contingent on the engine's temperature.
What to Do When Your Car Overheats: Safety Tips and Immediate Action Steps
The following are helpful tips and procedures you can carry out if your car heats up:
- Before cutting the engine's power, immediately drive your car to a secure area. Refrain from placing your car in an area that features an incline or is close to combustible elements.
- Once it is secure, switch off the motor to avert additional harm.
- Allow the car to cool. Don’t open the hood or touch the radiator while it’s overheating. Depending on the heat, this could take around 30 minutes or more.
- Once the motor has cooled, assess the coolant volume in the radiator or overflow tank. If insufficient, add either coolant or H2O.
- Visually inspect the automobile for any signs of coolant leakage. Check for wet spots on the ground. If you spot a leak, immediately take the car to get serviced.
- If you cannot pinpoint the root of the overheating or if it persists, seek technical assistance from an auto technician.
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