What is a Radiator in a Car and How Does It Work?

Although most people have heard of a radiator, they may not be aware of its purpose or importance. In the simplest terms, the radiator is the central component of a vehicle’s cooling system.

Its primary function is to monitor and regulate a vehicle engine’s temperature and prevent it from overheating.

What is a Radiator in a Car?

A radiator is the key component of the engine’s cooling system. Its main role is to disperse a mix of antifreeze and water throughout its fins, which releases some of the engine’s heat while taking in cool air before continuing to pass the rest of the engine.

Alongside the radiator is the spur line, water pump, and fan clutch. Each of these plays a different role in aiding the radiator to keep the engine cool.

The spur line dispatches warm coolant to the heater core to produce hot air when needed, while the water pump sends the coolant to flow throughout the engine.

Most importantly is the role of the fan clutch, which is to bring more air into the radiator and help lower the temperature of the antifreeze and water mixture.

Car Radiator Diagram

Parts of a Radiator

There are a few main parts that make up the radiator, and each plays a role in the cooling process. They are:

Core: The core is the largest part of the radiator. It’s a metal block that features the metal cooling fins that help vent the air. The core is where hot liquid releases heat and gets cooled before being sent through the process again.

Pressure cap: The pressure cap works to help seal the cooling system so it can remain pressurized. Coolant in the radiator is pressurized to prevent the coolant from boiling. It also keeps the system more efficient.

Inlet and outlet tanks: These tanks are where coolant flows in and out of the radiator and are located in the radiator head. Hot liquid flows from the engine through the inlet tank, and once it is cooled, goes out through the outlet tank and back into the engine.

Radiator hoses: Coolant moves to and from the engine via the radiator hoses. They are important for connecting the inlet and outlet tanks to the radiator and the engine.

How do Radiators Work?

A vehicle’s engine gives it the power it needs through the burning of fuel and the creation of energy from its many moving parts. This power and movement can generate a tremendous amount of heat throughout the engine.

It is essential to vent this heat from the engine during operation to avoid overheating, which can result in severe damage.

A radiator helps to eliminate excess heat from the engine. It is part of the engine’s cooling system, which also includes a liquid coolant, hoses to circulate the coolant, a fan, and a thermostat that monitors the coolant temperature.

The coolant travels through the hoses from the radiator, through the engine to absorb the excess engine heat, and back to the radiator.

Once it returns to the radiator, thin metal fins release the heat from the coolant to the outside air as the hot liquid passes through it.

Cool air flows into the radiator through the car’s grille to aid in this process, and when the vehicle isn’t moving, such as when you’re idling in traffic, the system’s fan will blow air to help reduce the heated coolant’s temperature and blow the hot air out of the car.

After the coolant passes through the radiator, it recirculates through the engine. This heat exchange cycle is continuous to maintain an optimal operating temperature and prevent the engine from overheating.

Why is your radiator important?

A radiator is important because it is the chief way your engine vents heat during operation. A malfunctioning radiator may cause significant engine damage caused by overheating – in most cars you see the billowing smoke on the side of the road is actually caused by malfunctioning radiators!

The most common cause of radiator malfunction is physical damage, which warrants a replacement of one or all of its components. Radiator function can be impaired by expired coolant or lacking coolant levels, which can be fixed via a coolant flush.

How To Flush A Radiator?

Vehicles need regular maintenance to keep working. While many of these maintenance tasks are small and simple, they can lead to big, expensive repairs if left undone for too long.

Flushing your car radiator is one of these tasks. The radiator is the heart of your vehicle’s cooling system, sending liquid coolant (antifreeze) to various parts of the engine to keep it from overheating.

Experts recommend draining and replacing the antifreeze in your radiator every five years or 100,000 miles, whichever comes first.

This process, along with running distilled water through the radiator before adding fresh antifreeze, is collectively called “flushing” the radiator. Flushing gets rid of rust and gunk that naturally builds up in your car’s cooling system.

Skipping this process could lead to a cooling system blockage and, ultimately, an overheated engine.

#1. Determine If You Should Flush Your Car Radiator.

When to flush a radiator depends on a couple of factors. One is the make and model of your car. Some cars only hold about 6 quarts of coolant, while others can hold up to 18 quarts. Knowing your car will help you determine if it’s ready for a radiator flush.

Another factor is the year of your car. If your car is on the older side, it’s probably time to flush the radiator. If it’s older than five years especially, it’s definitely time to replace the coolant by flushing the radiator.

When to flush a radiator is also dependent on your mileage. It’s recommended you flush your radiator out about every 30,000 miles to keep your car running smoothly.

#2. Make Sure the Engine Has Cooled.

Once you’ve determined you need to flush the radiator, also referred to as a coolant flush, place your hand on the engine block to check if it’s hot or cold. If it’s hot, don’t open it, and wait for it to cool.

Also, check the coolant temperature on your dash. As soon as your engine has cooled, pop the hood of your car.

#3. Drain the Coolant.

As soon as everything has cooled, look under your car to find the radiator drain petcock. The petcock is usually always located in the corner of the radiator.

Once located, get a pan of some sort, such as a disposable aluminum pan from the store, and place it directly under the petcock.

When in place, remove the petcock and let the coolant drain into the pan. When it’s finished draining, close the petcock and dispose of the coolant accordingly.

You can check with your local hazardous waste control organization on how to safely dispose of the antifreeze.

Tip: When draining the antifreeze, it’s recommended you wear protective gloves, eyewear, and clothing.

#4. Locate the Radiator.

Your radiator is a long metal tank next to your engine.  When you’ve found it, twist off the radiator pressure cap so you can begin the radiator flush.

Tip: Place the cap somewhere secure. You don’t want it falling into your car or getting misplaced.

#5. Pour Water and Cleaner into the Radiator.

Use distilled water and the radiator cleaner of your choice to flush out your radiator. Pour both into the radiator using a funnel, making sure all of the water and cleaner make their way inside.

Tip: If at any point you get confused, refer to the directions on the back of the radiator cleaner.

#6. Close the Cap and Start Your Engine.

After you’ve poured in the water and cleaner, close the radiator cap, start your engine and turn on your heat. Let your engine and heat run for 5 minutes at the minimum.

Doing this allows the water and cleaner to work their way through your cooling system, removing unwanted residue.

#7. Drain the Water and Cleaner.

After 5 minutes of the engine running has passed, turn off your car and wait for it to cool. When it’s cool, place the same aluminum pan back under the car under the petcock.

Remove the petcock once more to drain the water and cleaner mixture. If you think some water remains, start the engine so it pushes the rest out and into the pan. Then, close the petcock.

#8. Add the Coolant.

Using the funnel again, pour your coolant mixture into your radiator. Most cars take a 50/50 antifreeze mixture that you can purchase at any automotive store.

However, it’s recommended you check your owner’s manual so you know the correct antifreeze mixture to use for your specific car.

Also, check the manual for the amount of coolant you should use. Fill the coolant to the fill line.

If there’s backup coolant as you pour, turn on your car with the heat on to make it drain. Then continue pouring in the antifreeze. Place the cap back on once the radiator is full.

#9. Start Your Vehicle.

Once the radiator has been properly flushed and the new coolant added, turn on your car so the antifreeze can run through the system.

Turn off your car after a few minutes. You have now successfully learned how to flush a radiator.

To continue to care for your car, it’s important to invest in engine oil, hydraulic oil, and other car fluids that will help with the upkeep of your vehicle.

Why do car radiators fail?

The main reason for radiator failure is a coolant leak, which can lead to the cooling system failing.

If the coolant has not been checked or topped up properly, the radiator, hoses, and hose connections will become clogged and begin to rust. Over time, such corrosion will cause small holes or ‘pinhole leaks’ to develop in the car radiator.

This will result in engine coolant loss and a need for car radiator repair – or even the complete replacement of your radiator.

How to Maintaining Your Radiator

Just as with other parts of your vehicle, your radiator will also need to be checked and cared for regularly. Here are some tips for maintaining the radiator of your vehicle.

Take caution when checking the level of coolant and the radiator! Please bear in mind, you should never open the radiator cap or the heater hose connector cap when the engine is running, as hot coolant can erupt and cause burns and other injuries.

When checking the coolant, turn off the engine and wait for it to cool. Then, slowly and carefully open the cap with a thick cloth.

• When refilling the coolant level during the freezing winter season, it is crucial to add antifreeze and make sure they match at a 5:5 ratio. Otherwise, cool water can freeze within the engine. In addition, adding antifreeze with coolant can prevent the radiator grille or related parts from corroding.
• To prevent harmful particles or rust erosion, be sure to clear out the radiator at least once every 30,000 kms or 12 months(It is recommended to check the owner’s manual).
• Each time you change your oil, it is also recommended to take a look at your radiator hoses to see if there are any noticeable cracks or leaks.
• Lastly, if any electrical work was done on your vehicle when installing your radiator or heater, you should check to see if there are any stray currents as they can cause corrosion which can lead to radiator failure.

FAQs.