Heater Core Installation

Updated on May 4, 2019
Msmillar profile image

I write about maintaining and troubleshooting cars as well as jetskis and lawnmowers!

The Heater Core

Heater cores are basically the same. The shape varies depending on the vehicle they fit into. This one fits the 1993 Ford Explorer.
Heater cores are basically the same. The shape varies depending on the vehicle they fit into. This one fits the 1993 Ford Explorer. | Source

The Heater Core

I've been working on cars for twenty plus years and nothing, I mean nothing, was easier to install than the heater core on the 1993 Ford Explorer. I would say a child could install it!

I have heard that some vehicle models are difficult because a person can't access the heater core very easily. I've also heard that you have to remove the dash. I have replaced the heater core on a 1-ton Chevy, a Mustang, a Pinto (yep, a Pinto!) and the Explorer and never have I had to remove a dashboard. Heater core replacement on all four was straightforward and took less than an hour. The Mustang did require me to remove a couple of extra parts, compared to the Chevy, Pinto and Explorer, to access the heater core, but it was still child's play. The Chevy was as easy as the Explorer. I didn't take pictures of that installation, but I did of the Explorer installation!

Follow along with the directions and pictures and you'll be roasting in no time.

What Is the Heater Core?

The heater core is like a miniature radiator. The coolant from the engine flows through it as part of the cooling system.

First, the coolant in a warm engine flows through the engine, absorbing the heat.

Second, the hot coolant is diverted through the firewall into the heater core at the passenger area below the dashboard.

Third, when the heater is activated, a fan blows air across the heater core causing the warmth from the coolant, heated by the engine, to disperse into the cabin of the vehicle.

Last, the coolant flows out of the heater core, back through the firewall and to the radiator for additional cooling through the radiator and radiator fan.

When a vehicle is having an overheating issue it can sometimes help to turn the heater on high. The heater running on high helps the engine take the heat out of the coolant. Running the heater won't fix an overheating issue but it may buy you some time to get to a service station or safe exit.

How to Determine If the Heater Core Is Your Problem

Is the heater core the problem? Before purchasing or removing parts, you'll want to be sure that it is indeed the heater core that is the problem.

Fortunately, the heater core provides several indicators when it is going bad. Here are the indicators, in the order in which you might see them.

  1. Early on, the windshield starts to collect mist on the inside. This mist will get worse as the core goes bad. At first it will be noticeable near the dashboard, where the heater vents for the defroster emerge, and as time passes the damp area will slowly rise up the windshield.
  2. When the core starts to go bad you will notice the cotton-candy odor of radiator fluid or a smell of boiling water in the cabin of the vehicle.
  3. The floorboard of the vehicle, on the passenger side, will be wet.
  4. Finally, the heater will turn on, but no heat will come out of the vents.

A Quick Fix: Bypassing the Heater Core Instead of Fixing the Heater

Sometimes, when a heater core goes bad, a quick fix some people choose instead of replacing the heater core is to bypass it. To do that they go under the hood, remove the hoses from the heater, and plug them into each other. This way the coolant bypasses the heater core (see photo below). This was what was done on the Explorer. The person that bought it found out the hard way. When they were up in the snow and turned on the heater only cold air came out. When they popped the hood they saw the hoses were spliced together. That was a cold ride home!

Heater hoses bypassing the heater core.  I don't know why the white piece was used to connect the hoses, maybe it's all they had on hand.
Heater hoses bypassing the heater core. I don't know why the white piece was used to connect the hoses, maybe it's all they had on hand. | Source

Let's Remove the Core

Only work on the cooling system when it is cool. If it's warm, or hot, the coolant can burn you, and built-up pressure can spray it all over you.

  • Remove the two hoses under the hood, at the firewall, attached to the heater core pipes that are protruding through the firewall.

Heater core hoses at the firewall.
Heater core hoses at the firewall. | Source
  • Inside, on the passenger side, below the glove box, look for a black plastic cover with four screws in it, Remove the four screws. (There may be a decorative cover that would need to be removed first.)
  • The plastic piece will drop down. Slide it outwards to allow the drain pipe, going through the firewall, to come through.
  • You should be able to see the bottom of the heater core at this point. Pull the core down while pushing towards the wall. An assistant, if you have one, can go under the hood and push the pipes towards you through the firewall.

And you've removed the heater core! Now let's put it back in.

Pull the Heater Core Out

Start by removing the screws holding the cover on. Screw number one...
Start by removing the screws holding the cover on. Screw number one...
number three...
number three...
number four.
number four.
Now the plastic cover will drop down. There's a small drain plug that needs to come through...
Now the plastic cover will drop down. There's a small drain plug that needs to come through...
...in this picture you can see the drain that needs to slip through as the cover drops down.
...in this picture you can see the drain that needs to slip through as the cover drops down.
Now the heater core can be removed by pushing and then pulling down.
Now the heater core can be removed by pushing and then pulling down.

Put it Back Together

There may be insulation on the heater core you removed. If possible transfer it to the new core. If it can't be removed, pick some padding up at the hardware store and attach it to the new one the way it was it is on the old one (this is not imperative, it's just padding).

  1. Take the new heater core and slide it up where the old one was. Again, use an assistant to guide the pipes through the firewall if it will help. It can be difficult to line up the holes and push the pipes through at the same time.
  2. Once the pipes are through, working under the hood, attach the pipes to the hoses. It helps to hold the heater core in place.
  3. Now put the plastic piece back on and screw in the four screws you took out earlier.
  4. If there was a decorative cover, replace that too.
  5. Open the radiator cap and top off the fluid that escaped when you took the hoses off.
  6. Start the engine and look for leaks at the firewall connection.

Job well done!!

Installing the New Heater Core

Source

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

    Comments

    Submit a Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, axleaddict.com 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: https://axleaddict.com/privacy-policy#gdpr

    Show Details
    Necessary
    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 googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    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)
    Marketing
    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.
    Statistics
    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)