Types of a cooling system in automobiles

A car’s engine cooling system not only keeps the engine cool but also regulates its temperature to meet the needs of the engine’s operation. A radiator is one of the cooling system’s components that disperse heat. A fan ensures the airflow for radiator cooling. A water pump is used to help in raising the temperature to the desired operating level coolant pump. The coolants enter the engine, tubes, and other parts when needed.

A thermostat valve is then opened. Most cars today have an expansion tank that allows the coolant to expand, escape, and reverse as the cooling circuit heats up when the vehicle is turned off, and the engine cools. Both air and water cooling are used in automotive engines, and both methods are equally effective. Although to some extent, lubricating oil also aids in cooling the engine’s components. Below listed are the process and types of a cooling system in automobiles:

What is a cooling system?

The cooling system comprises of several parts that allow liquid coolant to flow into the engine block and head’s channels and absorb combustion heat. The heated fluid will then sent to the radiator for cooling via a rubber tube. An air stream cools the heated fluid as it enters the radiator through the little tubes. Modern internal combustion engines use both liquid and air cooling, but some engines use one or the other to remove waste heat.


While in some engines, the cooling is accomplished by transferring heat from a closed water loop to the radiator. Water is better able to move heat away from the engine faster than air. Due to the water cooling systems components, the engine becomes heavier, more expensive, and more complex. The technique works well with increasingly powerful machines that can move more weight but produce more waste heat.

How does a cooling system work?

The coolant is pumped out of the water pump through the internal engine block passage ways. The heat generated by the cylinders is collected as it travels. In a V-type engine, the excess heat from the combustion chambers is collected as it ascends to the cylinder head. The coolant travels to the thermostat if the thermostat is opened to let the fluid flow. The narrow, flattened tubes that make up the radiator’s core are where the coolant travels.

The air passing through the radiator cools the fluid inside of that area. It then exits the radiator through the lower radiator hose from this point. After then, it returns to the water pump. After this point, the coolant’s temperature drops, and it can absorb more heat from the engine. The engine determines a cooling system’s capacity. A large vehicle’s cooling system will require more capacity than a compact automobile with a relatively much smaller engine. The radiator is larger and has more tubes for the coolant to pass through in larger vehicles.

Types of the cooling system:

Car engine cooling systems have two primary types they are air cooling systems and water cooling systems.


1. Air cooling system:

These air-cooled systems, which have aluminum fins covering the engine block to transfer heat away from the cylinder, are typically found in vintage cars and motorbikes. Air is forced over these fins by a strong fan, which cools the engine by transferring heat to the atmosphere. The amount of heat cooled by air-cooling relies on several variables, including the total area of the fin surfaces, the velocity and volume of the cooling air, the temperatures of the fins, and the cooling air.

Most often, air-cooling is employed in engines with less power, such as those used in motorcycles, scooters, tiny vehicles, and small air cars, where the machine’s forward motion creates good air velocity for cooling the engine. Compact industrial engines also come with air-cooling options.


  • An air-cooled engine has a simple design.
  • Due to the lack of water jackets, radiators, circulating pumps, and the weight of the cooling water, they weigh less than liquid-cooled engines.
  • This cooling technique is beneficial in regions with harsh climates, such as the arctic, or where liquids evaporate more quickly, like deserts. Additionally, there is no chance of frost-related harm, such as cracking radiator water tubes and cylinder jackets.


2. Water cooling system:

Jackets are offered along the cylinders, cylinder heads, valves, and seats in the water cooling systems. The jackets absorb the heat of burning while the water circulates. The radiator will then be cooled by hot water using a fan as the automobile is being driven. The jackets will once more be filled with cooled water.


  • They constant the cooling of valves, cylinder heads, and other components.
  • The engine uses a specific amount of fuel.
  • When compared to the air conditioning system, the engine is less noisy.

Components of engine cooling system:

The parts of an internal combustion engines cooling system and their purposes are listed below:

Cooling fan:

The radiator, which is closest to the engine, is placed a little after the cooling fan. The component is made to control airflow and safeguard finger tips. The fan aids in lowering the radiator’s temperature by blowing air into it to cool the hot fluid while the engine is operating. The computer in the car controls an electric fan that is now in use. A temperature sensor tracks the engine temperature, which reports its findings to the ECU.

Water pump:

A water pump’s primary job is to keep the coolant flowing while the engine runs. Wherever the engine is running, the water pump rotates in that direction. The water pump and alternator are both driven by a component known as the fan belt.



The radiator’s core is made out of aluminum tubes that have been flattened. In addition, there is zigzag shaped aluminum strips wedged between the tubes. These fins’ purpose is to transfer heat from the tubes into the airflow. Eventually, this heat is transferred from the car. On either end of the radiator core is a polyethylene tank. This tank protects the radiator’s ends.

In the most recent radiator designs, the tubes are horizontal, and the tanks are on each side. In the past, brass was used to make the tanks, and copper was used to making the radiator core. These days, many people choose the inexpensive, easily manufactured aluminum-plastic system. It is also more effective.


A thermostat is a tool used to gauge the coolant’s temperature. The thermostat opens to allow the coolant to flow through the radiator if the coolant is hot enough. The flow to the radiator is restricted when the coolant is not at a high temperature. There is a provision for a bypass mechanism in such a situation. After passing via the bypass system, the fluid returns to the engine.

This system is crucial because it keeps the coolant flowing continuously and steadily throughout the engine. This constant flow keeps the temperature stable and prevents the development of hot patches. The engine reaches its ideal operating temperature faster when the flow to the radiator is choked.

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Coolant temperature sensor:

The engine’s temperature is monitored via the coolant temperature sensor. The ECU uses this data to control ignition timing and fuel injection. There are many different engines some contain several coolant temperature sensors. The temperature indicator on the driver console is updated, and the radiator fan is also managed using the information.

Most coolant temperature sensors are of the harmful temperature coefficient variety, implying that resistance will fall as the temperature rises. Depending on the car’s brand, the CTS may have a two-pin or three-pin type.

Pressure cap and reserve tank:

The pressure cap on modern radiators allows pressurized coolant to escape when it expands. Thus, the pressurize cap’s purpose is to keep the cooling system’s pressure constant up to a specific point. This cap had a spring valve calibrated in pounds per square inch. If the pressure rises over the predetermined pressure points, the valve opens, allowing some coolant to drain off. The coolant that leaks from the pressure cap is collected in a reserve tank reservoir. The tank, generally composed of plastic, can show the coolant’s temperature.

Heater core:

The heated coolant’s additional purpose is to heat the car’s interior occasionally. This device comprises a heating core joined by two rubber hoses to the cooling system. The hose returns the coolant to the top of the engine.

Freeze plugs:

Special sand is molded into the shape of the coolant tubes in the engine block during the fabrication process. After the casting has cooled, the sand is relaxed. The casting is then taken out using the engine block’s holes. Afterward, the coolant passes via these openings. So that the coolant doesn’t leak out, these openings are then sealed off.

Bottom line:

We looked deeply at the cooling system of internal combustion engines, which we defined as fluid movement throughout the engine to dissipate heat. In addition, we looked at the cooling system’s components in various places to examine how they function and the two types of cooling systems available for automotive engines such as air and water system. Cooling system plays a vital role in automobiles.