Engine cooling is the process of maintaining the temperature of an engine to its required manufacturing temperature. Engine cooling ensures that the engine does not overheat. Overheating of the Engine can lead to the breakdown of your vehicle.
Engine cooling system overview

Engine cooling system is one of the essential systems in a vehicle. We all know that an engine generates heat. As the engine generates heat, it also creates other cooling components for reducing its internal temperature.
The cooling system is essential because the car must maintain the particular temperature level required for it to function. If the temperature goes above that level, a lot of damage will take place. It could also damage your entire engine. The internal temperature level of an engine is of great importance. There is a required temperature expected for a combustion engine.
Functions of the Engine cooling system
- It helps to maintain the temperature of the engine
- It helps to ensure the system do not overheat
Components of the engine cooling system

The components of the engine cooling system are both internal and external. The Internal Components of a cooling system include:
- Top cylinder & Top cylinder gasket
In the top cylinder, there are separate holes through which lubricants and coolants flow. You can check our comprehensive article on the top cylinder to understand this concept better.

The top cylinder gasket on the other hand is the radiative point in between the top cylinder and the engine block. Its design depends on the kind of engine in your car.
There are Functional hoses that are of great importance when creating the gasket. For optimal performance, keen attention is crucial to ensure that nothing blocks the hose. The gasket will be designed based on the number of hoses on the surface of the top cylinder or the engine block. This design is to ensure that water can flow.
- Water pump

A pump is anything that can transmit fluid. There are two types of water pumps; the internal water pump is driven by the timing belt, while the second type depends on the external belt. If the timing belt breaks, this can affect the functioning of the water pump and can cause overheating. For further information about the timing belt, why not have a read of our other articles
- The Coolant
Water is a coolant. When you combine water with some chemicals, it becomes a vital coolant in the system. It will resist rust and also cool the engine.
The external component of an engine cooling system includes:
- External Fan
It is an electronic component. Therefore, it comprises brush, bushing, amateur that has a magnetic feel blade. It is heat resistant. It helps to cool down the engine.
- Radiator

This has a reservoir with hoses around it for the coolant fluid to flow around the boundaries. When it moves around, it returns to the base known as the reservoir. The radiator also has cells which are where the water flows. You can read our article on Car radiator fans, types, and symptoms.
- Thermostat
The thermostat is that component that works with increased internal temperature or heat, and at a particular degree, releases water to flow around the system. It determines when the water will flow.
How the thermostat works
- At a set temperature, the thermostat stops the water that gets into the cylinder. It also prevents the water from entering the engine compartment.
- When the temperature in the engine increases, it will open up for water to flow and circulate between the radiator and the hoses
- Thermistors: It is the temperature switch that helps to regulate the temperature level. It tells us the temperature of the engine. The stable temperature level for every automobile is 90 degrees. As a car owner, take note of the information coming from the thermistors on the instrument cluster or dashboard.
Once your vehicle is experiencing overheating, it is evident that one of these components has a fault.
How is an engine cooled?

In a typical engine cooling system, the radiator houses the water. The water from the radiator goes to the top cylinder directly. The top cylinder has two hoses connected to it; the upper and the lower hose. The upper hose goes directly to the radiator, while the lower hose goes through the thermostat.
When the temperature of the upper Hose in the top cylinder spikes, while the temperature of the lower Hose is low, there will be overheating.
The water passes through the upper hose to the top cylinder, and the top cylinder sends it into the thermostat through the lower hose. The thermostat closes until the temperature increases to a certain level. When it gets to that level, the thermostat will release the water, and it starts flowing. It returns to the radiator.
The engine must generate heat as long as it is in use. The fan oscillates to reduce the engine temperature. When the temperature rises above 90 degrees, the fan increases its speed and reduces the engine temperature. The engine component has an inbuilt water pump and also contains water that is not visible.
The water pump transmits and regulates the water inside the engine to ensure the water flows fast. As the water gets into the engine, the water pump helps to regulate. This regulation is to reduce the hotness of the water.
The temperature will build on the thermostat, and at 90 degrees on the thermistors, the thermostat will open. Furthermore, the thermostat will then release and circulate the water around the system.
Once the water starts circulating, the temperature in the engine will reduce to the maximum level. At this point, the fan and every other component will drop as well. As soon as the temperature builds up again, the process starts all over. We have a well-written article on the Best radiator stop leak.
How can you improve your engine cooling?
- Your external fan should be intact: There are two regulation units of a fan. We have the lower unit without an Air Conditioner where the temperature is within the maximum of 85 to 90 degrees.
When the temperature rises above 90 degrees, the AC will start working as it requires more heat. Then, the fan will increase and reduce the temperature to the maximum level. When it gets to 90 degrees, the fan will decrease again.
- Your water pump should be intact: The water pump transmits the fluid to circulate all over the system.
- Your top cylinder should also be flawless: It allows the water to flow after pumping.
What causes engine overheating?

- Faulty external fan
- Bad Water pump
- Leaking Radiator
- Damaged Top cylinder heads
- Defective Top cylinder gasket
- Broken Thermostat
- Malfunctioning Thermistor
- The irregular temperature of the hose.
Using water as a coolant for engine cooling

Water is also a type of coolant, and you can use it in place of the coolant. Coolant is water combined with chemicals. There is one disadvantage in using ordinary water as a coolant. The disadvantage here is often associated with the rust that forms due to corrosion in the system.
A potent coolant that is well mixed with chemicals will resist rust in the system. There are several fake products out there, and you may not be able to detect them. Some coolants you buy are very acidic. We advise that you mix such coolant with water to neutralize the acidic content.
The acidic content can destroy the top cylinder and the gasket. There is the original coolant which you can use without adding water. It has been well mixed and can serve perfectly.
Therefore, you should be aware that in every reservoir, there is a maximum and minimum level. Do not exceed or be below it. If you fill it to the brim, the water will not flow, and it will result in overheating in your engine.
How often should the fluid be added?
If the cooling system is intact, the water or coolant in the system can stay for a long time. Recall that the system is adiabatic; the water circulates and returns to its initial state. The water or coolant does not flow out of the system if there is no leakage. Notwithstanding, the fluid can remain in the system for long without any need for addition if there is no deformation in the system.
Is the air conditioner part of the cooling system?

The air conditioner in your automobile is not part of the engine cooling system. Therefore, the air conditioner is just for the internal temperature of your car. It cannot cool the engine. Therefore, the cooling system of the engine also acts as a coolant for the air condition system.
Conclusion and final words on engine cooling from the expert
Always observe the reading of the Thermistors. The thermistor will show the level of temperature in the engine. Furthermore, some thermistors use calibrated bars, and others use numbers in degrees.
The thermistor that uses a calibrated bar shows a heating symbol on the dashboard. The beginning level of the heating symbol is the maximum heat level. When the heating symbol increases, it is dangerous to your system.
Nonetheless, the thermostat that uses a number degree will indicate in 100 to 1200. When it shows anything above 900, then there is an issue in the cooling system.
Furthermore, there is a common thing you should be aware of when driving with your air conditioner. If you notice your air conditioner is not cooling, check your external fan. It could be that one of the components of your fan is faulty, and this will cause the fan to cease.
When your engine fan stops, it will not cool your condenser, and radiator causing the air conditioner to malfunction. Also, ensure that the water level in your reservoir is at the maximum level. Do not exceed the level.