Question about 1998 Ford Expedition

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Ten months ago the local Ford dealer replaced the heater core and temp blend door on my '98 Expedition. The heater core failed again and I was told that due to oxidation I will basically continue to have this problem. The system was flushed when I had the first core replaced. Does this failure make sense? Is there something else that should have been done the first time the heater core was replaced?

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There may be a corrosive in the system. Flushing the system should be done at least every 2 years. Your vehicle is now 12 years old, but I have not seen a heater core go bad in 10 months, it may have been defective, and should have some type of warranty.

Posted on Feb 03, 2010

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How do I change the blend door actuator on a 1997 Ford Expedition

This is a big job. You have to drop steering colum, dash, etc. about 6-8 hour job just to get to the heater core where the blend door is located. Go to youtube and look for video on "heater core replacement ". The video is great. they show you all the hidden bolts and screws. The door is on the front side of heater core. It costs about 15-20 bucks at oreillys auto parts. A tough job for a cheap part. Good luck. I did mine in 2 days. First day disassemble and 2nd day assemble. Take your time. The dealer will charge you 800-1200 dollars for the job.

Feb 11, 2015 | 1997 Ford Expedition

1 Answer

How do I change a blend door actuator on a 97 Ford Expedition

Lonnie. This is a hard job but heres your answer. I have done this twice myself but it was for heater core replacement the blend door is connected to the heater core assembly. Go to youtube and search "ford expedition heater core replacement". This video is outstanding the guy who made it points to all the hidden screws and bolts. It is an all day job just getting to the heater core. You have to drop the steering column and take off the whole dash to get to the door. both times i did this it took me 2 days. One day to disassemble and the next day to assemble. If you take to dealer be prepared to spend between 900-1200 dollars. The climate door only cost about 20 bucks. God bless you and keep me posted.

Feb 11, 2015 | 1997 Ford Expedition

1 Answer

98 expedition 9heater blows ice cold air. blend door replaced,heater core and radiator flushed. i think the

heater hoses clogged up, check where heater hoses connect to engine for clogs. Rust and corrosion love to build up in these locations.

Dec 16, 2013 | 1998 Ford Expedition

1 Answer

My 1997 ford expedition is only blowing cold air, is there a fuse i could change or is it the heater core?

Sounds like the common blend door failure on the Expedition. The problem is either with the heater core not getting hot, or the blend door not diverting air through the core. This is a common problem that Fords have. It is caused by the blend door getting stuck. This door is located behind the glove box and it controls the flow of Heat and A/C. Its probably stuck or broken, allowing the cold air from outside to come in instead of the heat from the heater core.
The heater core is difficult to change on the Ford trucks. They have it buried in the plenum box and you have to remove the steering wheel, steering column, dash, evacuate the refrigerant system, drain the radiator, and remove the plenum box to get to the core.

Replacing the core is easy, getting to it is a day's work. The Expedition is particularly difficult to get to. It is almost above the transmission tunnel and well buried behind the dash. The Expedition uses the same plenum box as the F150, so any information on that system applies to the Expedition/Navigator.

You need to be sure that the heater core is really the problem before tackling this job. If you have a pool of coolant on the floor, you'll have to go after the core. If the problem is lack of heat, there are some things you need to eliminate before tearing into the truck. You need to make sure that coolant is flowing through the core. Check the temperature of the heater hoses going into the firewall when the engine is cool and see if they warm up together as the engine warms up. If both hoses get hot at about the same rate, this is a good indication that coolant is flowing through the core. You can also remove the hoses and flush the core with a water hose splice from Home Depot and a water hose. Water should flow unobstructed through the core.

If it appears that coolant is flowing and you don't have obvious leaks, the next step is to check the blend door. This door controls the air flow through the heater core and failure is common on Ford trucks. When the door breaks, it can block the flow of air through the core and kill heat and will also have an impact on AC. If the system seems to work intermittently, it's a good indication that the door is broken and rattling around randomly blocking or opening the passage to the core.

For diagnostic information on how to check the operation of the blend door and a cheap easy fix, check the heatertreater listing on Ebay or the web site at The dealer fix for the blend door is basically the same procedure for replacing the heater core, so it will be expensive. The HeaterTreater alternative will solve the problem at a fraction of the cost and work and is well within the capability of the average shade tree mechanic.

You can try to fix it yourself if you check THIS VIDEO: Ford Expedition Lincoln Navigator

Hope helps.

Dec 21, 2010 | 1997 Ford Expedition

3 Answers

1997 ford expedition has no heat. blower works replaced thermostat. now what

Under the middle of the dash is a part called a blend door actuator it is located between the floor board and the heater housing. It control the door that opens and closes allowing heat to exchange.These go out all the time.

Feb 09, 2010 | 1997 Ford Expedition

1 Answer


You hot air comes from the water circulated through the heater core. It is like a miniture radiator with water flowing thru it constantly. So by opening the "Blend Door" you are permitting so much of this hot air to pass thru.

Seems like for some reason your heater core is plugged up. Just like a radiator can be. So water may be passing through your heater core but not passing through fully. Your heater core gets hot from water passing throught it from the engine. Then your doors open up, in proportion to how much air is permitted to pass over the heater core.

Suggest to remove the heater core and replace it. Seems the blend doors are working properly but again, if you have a non working heater core then no air can pass over the "Hot Core" for you to recieve hot air.

If you are not mechanically inclined, then go to a local parts store and you can buy a car manual, such as Chilton's or Hane's Car manuals, for your year and make to show you how to replace it. Then you can also have it for any other problems that may arise.

Jan 24, 2010 | 2000 Ford Expedition

2 Answers

How to replace heater core in 98 ford expedition

Heater core is a lot of work, but not extremely technical. You do have to remove the console, if applicable, and most of the passenger side dash materials, until you can get to all the small bolts on the bottom of the black blower unit. Beware of all the blend doors, they have to go back in the right places!. Then, to get the old core out, you may want to cut the metal tubes of the heater core, so you can work loose the hose connections to fit the new one. Strongly recommend Ford OEM replacement core, about $110, for fit. Also check closely the bottom of the blend door axle for cracks, you may want to replace it (about $35) while you are there. Local A/C shop with good reputation quotes $350 labor for this job. Good luck!

Oct 21, 2009 | 1998 Ford Expedition

1 Answer

1988 Ford Exppedition heater in the front will not work


Sep 05, 2009 | 1998 Ford Expedition

3 Answers

I have no heat on a 2001 ford expedition

i think you may have a tempature blend door failed or broken in the ac-heater plenum assembly, like wow i know that sounds extreme but ive done a lot of them. the door controls airflow between the heater core and evaporator core for heating or cooling. the hinge on the door breaks and it stays in whatever position. the door is controlled by an electric actuator.
first when the engine is warm and running, feel the heater hoses that go into the passenger compartment through the firewall.
see if both are hot. if they are then the problem is inside the passenger compartment and coolant level, themostat, heater control valve, and all that is ok.
under the center of the instrument panel, to the right closer to the passenger side, is the temp blend actuator. wiht a flashlight and some hunting you can tell if it is moving when you change from hot to cold on the controls. if it is moving the door is broken inside.
the dash has to come out and the plenum partially dissasembled.
good luck

Dec 22, 2008 | 2000 Ford Expedition

2 Answers

Heater valve

there is no heater control valve in this truck, heat control is done through what are called blend doors. So the issue may be the front blend door motor has failed, this is very common on all Ford heatimng systems except the Focus.

Dec 15, 2008 | 2000 Ford Expedition

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