Reasons Why a Car Overheats


Any day, you drive your car down the road. Nothing bad seems to happen when suddenly, a strange smoke exits the front of the vehicle. What are you afraid of? The indicator of the temperature of the car goes up without stopping.You stop the vehicle, you get down, you open the hood and you see the engine of your car boil like an erupting volcano.

What happened? In this article, we list the reasons why a car can overheat and how to act in case you happen to a scene like the previous one.

What Happens When Your Car Overheats

Refrigeration system

The first thing to know is that any engine has a limit. Regardless of the fuel used or the vehicle’s production model, it can, at a certain moment, stop working optimally, causing what we know colloquially as engine overheating.

Overheating of the engine is caused mainly by two reasons: damage to the different components of the vehicle’s refrigeration system or drawbacks with the engine lubrication system.

The cooling system exists precisely to maintain the balance in the temperature levels in the engine (which depends essentially on the design of the engine, but in general must be between 80 and 100 ° C).

Only between 20 and 30 percent of the energy released by the fuel during the time of the explosion in an engine becomes useful energy; The remaining 70 or 80 percent is lost practically in the form of heat. The inner walls of the cylinder or jacket of a motor can reach temperatures around 800 ° C. Therefore, all motors require a cooling system to help dissipate that excess heat.

How does the cooling system work?

An engine can be cooled by water or air (depending on whether it is a car or a motorcycle). When it works by air cooling, the motor consists of dissipation fins that evacuate the heat from the motor and thus reduce its temperature. Bikes are the main vehicles that use this type of cooling, in addition to the boats (outboard motor).

Water or coolant are the elements most used to control the temperature of an engine and fulfills this function through a complex system composed of the following elements:

  • Radiator: The radiator is a device that connects to the engine and that fulfills the function of the heat sink. A liquid is pumped to the engine, typically a mixture of water with alcohols with a high capacity to absorb heat. The idea is that the fluid circulates through the engine, absorbing the heat and then going to the radiator so that it cools there. A leak can lead to engine overheating.
  • Hoses: are responsible for transporting the water or coolant that enters and leaves the engine in order to cool it. Its breakage or poor condition is the most common causes of the temperature of a car to rise disproportionately.
  • Water pump: Its purpose is to maintain the necessary circulation of the coolant. The useful life of this element is very long and can only be damaged when the liquid deposits are left without this element.
  • Tank Jar: The typical failure of this element is that its cap loses seal capacity, causing the liquid to escape there.
  • Thermostat: if this valve, which allows the passage of the coolant to the engine to absorb the heat generated in it, is damaged, can lead to several incidents: not open and close properly, there may be an increase in fuel consumption And overheating of the system.
  • Fan: without a good job of this element the radiator may not receive enough air to lower the temperature of the coolant stored there.


If the engine runs above its optimum temperature, oil viscosity can be decreased, engine wear can increase and parts can be soldered by increasing temperature.

On the other hand, if the engine works below its optimum temperature, the fuel consumption increases, since the engine needs a specific temperature necessary for its proper operation. Engine parts can also wear prematurely, as they are designed to expand due to the effect of heat to a certain size. In addition, the power is reduced by not having the right conditions for a correct combustion.

Any damage to one of these components can cause the vehicle to overheat. That is why it is important that you follow the following recommendations to avoid further damage to the engine and its different components (from breakage and damage to parts to total engine failure).

  • Periodically check the condition of the belts, coolant, leaks, and patches or coupling points of the hose towards the engine as there may be signs of rust (a sign that the liquid is filtered at this point).
  • Check that the motor fan is activated when the car is turned on.
  • If smoke comes out, stop the vehicle, do not open the coolant reservoir jar as you can burn it.
  • It is not advisable to put water or coolant to the tank when it is hot because at that moment there is pressure in this element and you can burn it. Never move the car when the vehicle presents a failure in its cooling.
  • Staying too long with the vehicle on and stopping may cause engine overheating. If you go into a trance and you have to stay in it for a long time, you’d better turn the car off.


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