ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How A Radiator Works

Updated on February 20, 2012


Your car's engine runs at very high RPMs(revolutions per minute) which you can imagine generates a lot of heat. 

Somehow the engine has to be kept cool to prevent it from breaking down, yes I guess it could be cooled by air but that might not work so well. So we all have radiators in our cars, but how do these work?

Here's a step by step guide to how your radiator works...


It all starts with coolant and water. You have to fill your radiator with a mixture of water and coolant.

Coolant is also called antifreeze, because it does just that it keeps the water in the radiator from freezing in cold weather.

The mixture of water and coolant runs throughout the engine to cool it down then back to the radiator and the cycle begins again.

The Fan

The radiator fan is the next part in the cooling system. The fan runs, when it needs to or in some older vehicles the fan runs whenever the engine is running, to cool the radiator and the fluid inside it. 

The fan is located directly in front of the radiator and behind the grill, it pulls in cold air from outside of the vehicle.


The thermostat measures the temperature of the water/coolant and when it reaches a certain temperature it triggers and tells the fan to come on to cool the radiator fluid.


After going through the thermostat the coolant/water then moves into the engine, cooling it on it's way.


Now back to the radiator goes the fluid. The mixture runs through the engine and returns to the radiator.


The reserve or overflow tank is often located on the side of the engine bay. It stores coolant/water.

What happens is this...

When the engine warms up so does the water/coolant and when it does this is bubbles or boils, but where does it go? Into the reserve!

The hot water goes into the reserve until the engine cools down.

Once the engine begins to cool the radiator fluid stops boiling and the fluid level goes down, but if the fluid level goes down the car will overheat, so the radiator pulls water/coolant from the reserve tank to make up for it.

You see if there was not reserve tank the water would boil over and out of the radiator, if there was a release at least, and then when the engine began to cool it would overheat!

It's all one continuing cycle, perfectly invented so we can get around safely and reliably!

Pictures To Refer To

Radiator hosing diagram
Radiator hosing diagram
Car Radiator
Car Radiator
Radiator Fan
Radiator Fan
Radiator Overflow/Reserve Tank
Radiator Overflow/Reserve Tank
Thermostat housing
Thermostat housing


    0 of 8192 characters used
    Post Comment
    • profile image


      7 years ago

      I have idea related to radiator. we can make AC using radiator, in radiator we just use water not any other liquid. I have done experiment in my Home.

    • profile image


      8 years ago

      good tutorial

    • profile image


      10 years ago

      your description of thermostat does not describe the thermostat in the photo. i.e., there are two thermostats, and one is a temerature operated valve that prevents coolant circulation until it reaches operating temperatures. Also moderates the flow in cooler weather to keep the engine warm at all speeds. ( I live in Canada. Driving without a thermostat installed equals no heat in the car. Brrr!!)


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)