Internal Combustion engines generate extremely high temperatures, with combustion gasses reaching around 2300-2500°C. Such high temperatures can burn the oil film between moving parts, which may cause seizing or welding of components. Therefore, it is essential to reduce this temperature to about 150-200°C, where the engine operates most efficiently.
On the other hand, excessive cooling can diminish thermal efficiency. Therefore, an engine cooling system is crucial to sustaining the engine at its optimal operating temperature. So, in this blog, we will cover what is engine cooling system, its fundamental purpose, and the key components of engine cooling systems, providing you with a thorough understanding of this essential automotive system.
Contents
What is an Engine Cooling System?
An engine cooling system is a network of components that cooperates to control the temperature of an engine that utilizes the principle of internal combustion. The important function of the cooling system is to take the excess heat away from the engine, transfer it away, and dissipate it into the surrounding air.
This process maintains the engine’s efficiency, keeps it from thermal damage, and increases its lifespan. Additionally, the cooling system plays a significant role in achieving optimal temperature rapidly, leading to improved fuel efficiency and reduced emissions.
Engine Cooling System Components
Now that you know what is engine cooling system is, let’s look at the cooling system components and its operational details:
Radiator
In the engine cooling system, the radiator is responsible for transferring the heat from the coolant to the air that surrounds it. The primary location of the radiator is the vehicle’s front, usually made of thin metal fins and tubes that the heated concentrate passes through. The passage of coolant through these tubes is cooled by heat dissipations into the air ensuing as a result of the motion of the vehicle or the radiator fan.
Radiator Cooling Fan
The radiator cooling fan is an important vehicle cooling system component that helps supply air to the radiator when it is standing or moving slowly. This cooling fan is usually driven by an electric motor and controlled by the PCM (powertrain control module) or a temperature sensor. It operates only when a threshold is reached, ensuring adequate air supply to the radiator and quick heat dissipation.
Radiator Expansion Tank
The radiator expansion tank, also known as the overflow reservoir or coolant recovery tank, is a small plastic container that is connected to the cooling system through a small hose. This tank accommodates the expansion and contraction of the coolant as it heats up and cools down. When the coolant heats up, and its volume increases, the expansion tank allows some of the coolant to overflow into it, thereby reducing the pressure in the cooling system slightly.
Engine Coolant
Engine coolant, a mixture of water and ethylene glycol (antifreeze), is used to remove heat from the engine. This coolant is mixed with water to prevent freezing in the cold and increase the boiling point to increase steam pressures needed for steam heating directly and reduce heat transfer with less fluid volume.
Thermostat
The thermostat regulates the engine’s temperature. By controlling the coolant flow to the radiator, it ensures the engine heats up quickly and maintains a constant temperature.
At low temperatures, the thermostat blocks the coolant’s path to the radiator, recirculating it within the engine to help it warm up. When the coolant temperature rises to 180-195°F (82-91°C), the thermostat starts to open. By 200-218°F (93-103°C), it is fully open, allowing coolant to flow through the radiator to dissipate heat.
How Does the Engine Cooling System Work?
The engine cooling system operates in a continuous cycle, with the coolant being circulated by the water pump through a meticulously designed network of passages and components. Here’s a step-by-step breakdown of this complex working process:
- The water pump draws the coolant from the radiator and circulates it through the engine block and cylinder head. Here, the coolant absorbs the heat produced by the combustion process.
- After the engine has warmed up, the coolant flows into the radiator. It transfers the heat to the environment as it moves through the narrow metal fins and tubes, which offer a more significant surface area to the cool around them.
- “After the coolant flows through the radiator, its temperature is significantly reduced. It then needs to cycle back to the water pump to be reheated. This process is cyclical, with the refreshed coolant being pumped back into the machine to absorb additional heat.
The thermostat plays a big part in the regulations over the coolant temperature during the whole cycle. If the engine is cold, the thermostat is closed, notclosed not allowing the coolant to reach the radiator and making the engine warm very fast. After the required operating temperature is reached, the button on the thermostat opens, using the coolant to move to the radiator for better cooling operation.
Signs of Cooling System Problems
- Engine overheating
When the temperature meter on the control panel indicates overheating, then it’s the indicator that your vehicle has a cooling system issue.
- White exhaust smoke
The presence of white smoke coming out through the exhaust can be a cause of coolant burning inside the engine caused by leakage, usually the head gasket.
- Frequent overheating
f the engine overheats often, even after you refill the coolant, that’s an indicator of a serious malfunction that needs to be properly checked and repaired by specialists.
- Coolant discolouration
The coolant should stay a neon, clear colour. When the coolant changes its colour or gets mixed with something else, it shows corrosion or foreign substances in the cooling system.
Garima Global is one of the foremost exporters of engine parts like radiators in India. We have developed an extensive range of genuine, OEM / OES and aftermarket radiators and oil coolers with our vendor-partners in India and our customers in over 70 countries trust us to keep their clientele’s engines and tempers, cool.
Conclusion
An effective engine cooling system will remove 30-35% of the total heat generated. By circulating coolant and dissipating heat through the radiator, it prevents overheating and ensures the engine’s longevity. Understanding the components and how the system works can help you identify potential issues early on, allowing for timely maintenance and repairs.
FAQ’s
- What is the function of the radiator expansion tank in the cooling system?
The radiator expansion tank accommodates coolant expansion as it heats up, preventing excessive pressure buildup. It also serves as a reservoir for topping up coolant levels when needed.
- What happens if the engine cooling system fails to function properly?
If the cooling system fails, the engine will overheat, which could trigger the damage of stretched cylinder heads, blown head gaskets, cracked engine blocks, or even engine failure.
- How does the thermostat regulate the temperature in the engine cooling system?
The thermostat uses a mechanical device to control the flow of coolant through the engine. When cold, it’s closed to allow the engine to heat up more rapidly. Once operating, it opens to allow hot coolant into the radiator to cool, which keeps an engine in the best temperature range.
- Are there different types of engine cooling systems, and how do they differ in operation?
There are two main types of engine cooling systems: liquid-cooled and air-cooled. Liquid-cooled systems are known for circulating a liquid coolant through both the engine and the radiator, which results in the efficient removal of heat and the creation of a suitable temperature. In contrast, air-cooled systems rely on the airflow around the exterior of the engine for heat dissipation and do not require a liquid coolant.
