Cooling System


Cooling System

The main purpose of the vehicle engine is to convert chemical energy (from the fuel) into mechanical energy that will propel the vehicle. The main energy conversion occurs in the engine block, and particularly, within the engine cylinders where spark plugs ignite the fuel which pushes the piston and provides mechanical energy. Basically, a series of explosions have to occur within the engine for mechanical energy to be produced. The result of these explosions is that the engine tends to heat up very quickly. Since overheating will limit the efficiency of any engine, a vehicle needs a cooling system in place to regulate its temperature.

What is the Cooling System?

When it comes to engines, there are two types of cooling systems: air-based and water-based variations. Air-based cooling systems rely on a fan to cool the components within the engine. This only works for smaller engine systems. Larger and more complicated systems, such as a car engine, require water-based cooling systems. Water is an excellent, and affordable, conductor of heat. The car engine cooling system works by passing cold water through the engine components which ‘absorbs’ their excess heat. The hot water is then cooled and returned back to the engine to further cool it. This ensures that the vehicle engine is kept at a constant temperature that is optimum to its performance. Obviously, this is a much simplified explanation of the vehicle cooling system. A more in-depth analysis that covers the different components of the cooling system will be provided further below in this guide.

Importance of a cooling system

Before we get into the different components of the car engine cooling system, we need to understand why it is so important to regulate the temperatures in a vehicle’s engine.

A vehicle’s engine works best at hot temperatures. This is why car owners are advised to let their engine run for a bit when you start your vehicle in the morning. But when your engine overheats, it starts developing long-term damage.

The purpose of the cooling system is to ensure that your vehicle engine temperature remains within the small window where it can achieve peak performance.

Some of the damage that your engine can develop due to overheating include:

Warped Piston Heads

The piston head is meant to fit snugly into the cylinder to ensure that there is no leakage in the fuel chamber and the chamber that holds engine oil. When overheated, the piston head gets warped and allows oil to seep into the combustion (fuel) chamber. This not only reduces the power output developed by the fuel combustion, but it also adds to the pollution created by the ensuing exhaust fumes.

Damaged Piping

The vehicle engine has numerous pipes to allow the flow of engine oil, fuel as well as the water coolant. Most of these pipes are made from rubber, which is prone to damage when exposed to excessive heat. When your engine overheats, these pipes are damaged which result in reduced vehicle performance or total engine failure if not addressed in time.

Parts of a Cooling System

While no two cooling systems are perfectly identical, they all share similar components. The main components in a car engine cooling system are:

The Coolant

This is the fluid that dissipates the heat from the heated engine components. Usually, this is just made up of water. However, in colder climates, anti-freeze is added to the water to ensure that the water does not freeze during particularly cold winter months. The recommended ratio between water and anti-freeze is 50:50. For colder climates, more antifreeze can be added.

Intercooler or Charge Cooler

Most high-performance engine upgrades will include a turbocharger or supercharger. Both systems compress the air that is delivered to the combustion chambers increasing the energy output of the fuel burnt. The compression process generates heat, which when excessive, can actually reduce the engine performance. This heat is regulated by an intercooler or a charge cooler. The main difference between the two cooling systems is that intercoolers use cold air while charge coolers are water based cooling systems.

The Radiator

The radiator is the main reservoir that holds the water coolant. It is placed at the front of the engine where it is exposed to the external airflow that will cool the heated water before it is piped back into the engine. A fan is usually placed behind the radiator to further cool the water if the natural airflow is not adequately cooling the liquid. Depending on your vehicle, there are many different types of radiators available such as performance radiators and aluminium radiators.

The Thermostat

Since every engine has its own ideal working temperature, a thermostat is required to keep track of the engine temperature. As the engine temperature increases, the thermostat allows the radiator water to get into the engine and cool it.

Water Pump

This is the mechanism that ensures that the coolant is pumped through the engine. Gravity is not sufficient to provide the required energy to pipe the coolant throughout the engine. Heavy duty and high performance cars which use high performance radiators or aluminium radiators tend to have more powerful water pumps.


There is a complex set of pipes that connect the radiator to the parts of the engine that need to be cooled on a regular basis. Different types of piping are used, based on the engine. Just like a cooling system can use standard radiators or alloy rads, piping can either be rubber or metal-based.

Maintaining your Cooling System

Each of the above-mentioned components needs to be regularly checked to ensure that your cooling system is performing optimally. This should be a priority when your vehicle undergoes its regular checkup routine. A small leakage in the piping could end up causing total engine failure.

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