car radiator guide

An Ultimate Guide to Car Radiators: How It Works and How To Maintain

Daniel McDonald
Daniel McDonald9 min read
An Ultimate Guide to Car Radiators: How It Works and How To Maintain

An Ultimate Guide to Car Radiators: How It Works and How To Maintain

We all enjoy driving with loud music and some beautiful seaside landscape beside us, but we hate it when cars let us down. Being able to understand what the trouble with your vehicle is, solves half of the problem. Thus, if your car radiator refuses to operate efficiently, this article is for you.

Maintaining a vehicle's cooling system means taking care of one of its most essential parts. The cooling system of a car is one of its vital parts, as it cools down the engine to protect against overheating. While car radiators are easy to replace and maintain, some techniques make the process much easier for you and your car, so you can avoid running into problems down the road. 

This comprehensive guide to car radiators will walk you through everything you need to know about how car radiators work, what to do when they break down, and how to keep them working correctly.

What Is A Vehicle Radiator?

There is a whole new world under the hood of our cars whose components help our cars operate efficiently, but are we familiar enough with the cooling systems to tell if something is going wrong before it is too late and we are faced with an overheating engine?

As we all know, a vehicle needs fuel to burn, thus creating energy to move it. This chemical power creates heat. So, to keep your vehicle intact and avoid overheating the engine, you need something to vent the heat away from all the engine parts. Here the radiator enters the game.

The radiator cools the engine, which is the critical part of the cooling system. The radiator presents the heat exchange cooling the fluid responsible for cooling the vehicle's engine. A car radiator helps all the excess heat get out of the engine.

Releasing excess heat is its primary function. Car radiators are heat exchangers that help prevent your engine from overheating. The radiator transfers the heat from the hot coolant in your engine to the air outside.

The coolant needs to be at a low temperature by the water pump, and as the pump circulates through the engine, it picks up heat.

The hot coolant then flows into the radiator, cooled by the air passing through the thin metal fins. Once it has cooled, the coolant flows back into the engine to start the process again. If the radiator is not working as it should, it can cause severe damage to your engine.

For the radiator to start working, the thermostat between the engine and the radiator must detect excess heat. Next, the radiator releases coolant and water and sends them to the engine to lower the engine temperature and remove the heat.

When the process ends, and the liquid takes the heat, it returns to the radiator. Next, the radiator needs to blow air and cool down the liquid. Finally, the radiator does the exchange by replacing the heat from the engine with the air outside.

All radiators have thin metal fins. They help the heat quickly escape into the air outside. The fins work together with the cooling fan that blows air across the radiator.

Radiator's Location In The Vehicle

How do you locate the radiator? Just open your vehicle's hood, and you will see the radiator right in front of the engine. You will also notice the coolant reservoir next to the radiator, which is an essential part of the cooling system.

Main Components Of A Radiator

A vehicle radiator works with several important parts that keep high temperatures in control.


The core is the most significant part of the radiator. It is a large metal block with a series of metal cooling fins venting the hot air.

The coolant flows through these fins, and as it does, the heat from the engine transfers into the coolant and then into the radiator's metal. The core is the place where hot liquid releases all of the heat. Then, it is cooled before it starts the process again.

Radiator Hoses

How can the coolant move if there are no hoses in the vehicle? The radiator hoses are the part that moves the coolant through the engine.

Inlet tanks/ Outlet tanks

The inlet and outlet tanks are attached to the core, providing a place for the coolant to enter and exit the radiator.

The tanks are where the coolant moves in and out of the radiator. They are at the head of the radiator.

The inlet tank is there to receive the hot liquid from the engine. When the liquid is cooled, it will be released through the outlet tank and sent back to the engine.

Pressure Cap

The pressure cap is also attached to the radiator, and it helps to prevent overheating by keeping the coolant from boiling over.

The pressure cap seals the system and helps it stay under pressure. The liquid coolant is under pressure to avoid coolant boiling.

The Radiator Cools, But How? The Engine's Cooling System And Its Parts In The Vehicle

The cooling system has a few essential parts to remove the hot air from a vehicle. A car's cooling system comprises a radiator, radiator hoses, water pump, thermostat, and engine coolant.

The radiator is a heat exchanger that transfers heat from the hot liquid in the engine to the coolant. The radiator hoses carry the coolant to and from the radiator.

Water Pump

The water pump is there to circulate the coolant through the engine. It pushes the coolant through all of the system components.

The engine drive belt turns on the pump, and the spinning blades make the liquid pass through the system. Various gaskets and seals are there to keep the coolant in place.


The primary role of the thermostat is to regulate and control the engine's temperature. The thermostat controls the flow of coolant through the engine by opening and closing as needed.

When the engine needs to be cool again, the thermostat opens and lets coolant in. The thermostat will close when the engine is working at the average operating temperature, and there is no need for heat exchange.


Coolant is a vital element of the system that helps cool the engine. The engine coolant is a fluid that helps transfer heat away from the engine. The entire cooling system is under pressure to operate at a higher temperature than the surrounding air.

It is fluid pumped through all the system components to prevent engine overheating. It also lubricates all the parts it reaches. Therefore, coolant levels need to be checked regularly as part of the preventative maintenance of the vehicle.

Types of Radiators

There are two types of vehicle radiators: liquid and air-cooled.

Liquid-cooled radiators have a water jacket around the engine where a pump circulates water. The water absorbs the engine's heat and transfers it to the air passing through the radiator fins.

Air-cooled radiators use airflow to transfer heat away from the engine. Automotive technicians typically recommend a coolant flush every 30,000 miles every two years, whichever comes first.

What is the Best Kind of Radiator

A car radiator is a crucial part of the engine's cooling system. It is responsible for keeping the coolant at the right temperature. If the radiator malfunctions, it can cause the engine to overheat.

Aluminum radiators are the best kind of radiators. Aluminum radiators are more durable and efficient than other types of radiators. They also have a higher boiling point, which means they can withstand higher temperatures.

Why Should You Change The Coolant Fluid?

Regarding car maintenance, the radiator fluid is one of the essential fluids to keep an eye on. Over time, coolant degrades and becomes less effective at doing its job. Degradation can lead to several problems, such as a malfunctioning thermostat or power steering fluid issues.

Transmission fluid also affects coolant degradation, so it's important to change it regularly. Change this fluid to prevent rust build-up. You must also remove scale deposits because your engine might be overheated and the cooling system damaged due to their presence.

Bad/Failing Radiator

No one wants to deal with a failing radiator; this is why preventative maintenance such as checking the hoses, the coolant level, or the cap is so important.

As time goes by, most radiator parts start to wear down. So, how can you know your radiator is not feeling well?

  • Overheating. If you notice your vehicle overheating, the radiator might not work well. Since the radiator is the thing that removes the heat, overheating the engine means you need to check the work of the radiator immediately.

  • Damaged fins. If the fins are bent, the air will not be able to pass freely and will be blocked. Fins can bend due to the gravel that hits them when you drive. They can also be damaged if you clean them with high water pressure.

  • Leaking coolant on the ground. The radiator might leak or have cracks if you see some coolant on the ground. You will notice this when the car is parked, but also you can notice it even when you are driving. Low coolant levels mean radiator opening/crack.

  • Coolant changes color and texture. The coolant's color is usually yellow/green. If you are dealing with a failing radiator, the rust from it might contaminate the fluid and give it some different color, typically rusty dark because of the rust.

Overheating Cooling System And How To Prevent It

You must take care of all the car components to drive your car longer and safer.

If the radiator gets too hot, it can cause the engine to overheat and break down.

This is why you need to replace the radiator hoses regularly. Do this every 35/36,000 miles or every three years.

Hoses can easily break over time, so you should not drive more than the recommended mileage with the same hoses. They are made from rubber material and can break down due to high temperatures and rubbing.

Next, check your coolant level regularly and add coolant if necessary. It would help if you also focused on the coolant temperature gauge on your dash. If the coolant level is going down all the time, you should check for some leaks in the system. Observe since some of the leaking places are rather hard to notice.

Try to have the coolant flushed every 23/24,000 miles. Flushing helps remove radiator contaminants and rust. In addition, it will help components not rust and support the system to work at its best.

Pull over and instantly turn off the engine if it starts to get into the red zone. Next, you should check the radiator for leaks when the engine has cooled down. If you find a leak, you will need to take your car to a mechanic to have it repaired or replaced.

How Do You Replace a Radiator?

Replacing a radiator is not an impossible thing to do, but it requires some basic mechanical knowledge. You will need to have a new radiator, as well as some tools and supplies.

  1. The first thing you will need to do is remove the old radiator. You can remove it if you disconnect the hoses and unscrew the mounting bolts.

  2. Once the old radiator is out, you will need to clean up the area before installing the new one.

  3. Next, install the new radiator in the reverse order of how you removed the old one.

  4. Then, tighten the bolts and connections before filling the radiator with coolant.

  5. Finally, start the engine and check for leaks.

How Do You Extend The Life of a Radiator?

There are some ways to prolong the life of the car radiator.

  • Check the radiator for leaks and have it repaired as soon as possible if there are any. 

  • Keep the radiator clean by regularly flushing it out and adding fresh coolant. 

  • See that the cooling system is operating at the correct pressure by checking the pressure cap and release valve. 

  • Inspect the hoses and clamps for any signs of wear or damage, and replace them if necessary. 

  • Pay attention to the temperature gauge, and be sure to stop driving if it starts to get too hot. 

  • Avoid using coolant additives as they can cause corrosion in the radiator. 

  • Take your car for regular maintenance checkups to catch potential problems early on.


Is It Fine To Drive A Car With A Broken Radiator?

You can, but you should not. A damaged radiator will cause the engine to overheat, leading to complete engine breakdown. Instead, you should contact your service center if you notice any radiator problems.

How Much Does A Car Radiator Cost?

Of course, radiator costs depend on the type of vehicle, the size, the radiator location, and the labor. However, you might expect to pay from $500 to $1000 for a radiator replacement.

What Does Transmission Fluid Do For My Car?

Transmission fluid is there to lubricate all the moving parts of a vehicle. It also gives hydraulic pressure and friction to help the components of the car work. Finally, it keeps the transmission cool.

What Does A Puddle Of Antifreeze Under The Vehicle Mean?

A puddle of antifreeze means you might have a radiator leak. If the color you see is green or yellow, it is most likely coolant. However, you should check carefully to see what it is.

Why Do You Need Power Steering Fluid And Brake Fluid?

Power steering fluid, brake fluid, and other fluids are needed because they add pressure to the pump and thus improve the effectiveness of the power steering system. Brake fluid is there to help the car's brake system function properly.


Maintaining your car's radiator is key to prolonging your vehicle's life. Only a radiator in good condition can prevent engine overheating.

The radiator keeps the engine alive and takes care of its temperature. All of its components are there to help the coolant flow through the vehicle's cooling system. This system in the vehicle helps keep the fluid at the proper level.