Heater Core??? Or Not?? HELP!

[Dr.Spank]

I am hoping someone on here can verify what a mechanic has told me.

2002 4WD Exp.

Finally needed to start using the heat this year and there is none.
well, the heat works for about 30 seconds and then gets cold. Every once in a while, while driving longer distances 30+ miles, it will actually get hot for a while and then stop.

Mechanic told me it's the heater core. He said also that while replacing the heater core, I should replace the "door/valve" (opens and closes for the heat?) Not really sure what that is, but he said Ford has a crappy design on it.

I'm ok with replacing whats needed if I'm paying the labor to remove the dash anyway. i might as well replace what could go wrong under there.

My question though, is....can it be anything other than the heater core??
Is there anything else that "I" can check or change before I dump a gob of money down for the heater core.
Thermostat was changed and the mechanic apparently did some sort of "flush" .

If theres anything else it could be I'm hoping you guys in here can help. I really don't have the $500+ to slap down right now.

Pete

 

[rburch]

Do you have the EATC?

 

[Thermo]

Dr. Spank, like was mentioned, if you have the electronic heater controls, then that is normally the first suspect for me. After that, what I would tell you to do is to get yourself a source of compressed air. THen, next to where the starter solenoid is, the heater core hoses go through the firewall there. Disconnect those hoses and attempt to blow air through the heater core (place air hose on one opening, leave the other one unplugged). If you can blow air through the heater core with little restriction, then your problem is the blend door. If you get lots of restriction, then your heater core is plugged and you need to replace that. Based on how the heat comes and goes and when it does, it sounds to me that the core is plugged. But, blasting it with some air may be all that it takes to unplug the core. I did this to a neighbors car and I was able to remove the blockage. Granted, I used "water hammer" to get the blockage out. If you are not familiar with this, I will talk you through it or simply go to replacing the heater core.

 

[Dr.Spank]

glad i checked back..for some reason I'm not getting the "instant notification" e-mails off this forum..Not sure why..

Anyway...That you both..No I do not have the electronic heat control..It's all dials.


The mechanic I took it too did tell me he was gonna do some sort of flush , but then he said if he did it too much it can ruin the radiator?? not sure why or what that means.

So by what your saying , all i need to do is disconnect the two hoses and blow air through the core and if the air flows its the blend door??
So let me ask, reguardless if it's the blend door or the core, I will still need to remove the entire dash to get to it, correct??

 

[Thermo]

Dr. Spank, I think you can fix the blend door without having to remove the whole dash. The heater core, unfortunately, you have to remove the dash to do it.

As for proving the core good, yes, blow air through the core and if you get a lot out of it, then that proves the blend door is toast. no air, heater core is trashed.

As for the heater core flushing causing damage to the radiator, keep in mind that they are flushing acids through the coolant system in an attempt to clear the clog in the heater core. Aluminum is easily eaten away by any acid. So, the more you try to get acid to the point of blockage in the heater core, the more of the radiator you are eating away. make sense?

 

[rburch]

You could also let the truck get to normal operating temp and feel the heater hoses. If the heater core is blocked then one will still be cold.

 

[walnuts4x4]

blend doors have to have the dash removed since Ford made a one piece door.... so you have to get to the "phleum(sp?) box" were the door operates to either go hot or cold.... only way to do it without removing dash is to go the "heatertreater.com" method... it is a 2 piece door and you have to cut behind the glove box and seal the box after you replace the door with the aluminum tape used for house pipe... this is what I have have-way done.... my door broke so only had heat during the summer... so I made a brace and during the winter I block door open and summer I close the door.... either full AC or HEAT... still need to order the door from heater treater but too cheap and once I do the swap I'm good to go until the season changes then too late to order door and I forget... been almost 2 years...lol

 

[walnuts4x4]

http://www.youtube.com/watch?v=cCUzOUqW6Ms


http://www.heatertreater.net/

 

[Thermo]

rburch, what I am gathering from Spanks first post is that he is getting some flow through the heater core (ie, has a heat for a few seconds, but not much afterwards). So, he will still have 2 hot hoses unless he is running the heat at full blast for the check.

 

[rburch]

Thermo, Yeah i see that now! Sorry! I would try Thermo's suggestion and if that didnt work i would then try some CLR in just the heater core itself to help loosen things up, and then blow it out again.

 

[99exp]

need heat!

New guy here, having issues with the heat in my 99 expedition w/ dial teperature control knobs. My problem is I get decent heat on the floor however when I switch to defrost it gets cool pretty fast. This is what I've done so far: 1 changed the thermostat, 2 cut peep hole in plenum and the blend door operates as intended, closing heater core off when temp. dial in cold position and swinging fully open in the hot position. I can touch the heater core and it's hot so I don's suspect the heater core is clogged., I do feel quite a bit of cold air in the plemun. Question? is the there a fresh air make up damper that could be open so I'm heating external air and not cabin air?? Running out of ideas. The only damper I can see is above the blower motor and it moves toward the firewall when I turn the flow direction dial and swings back in the off position (towards the cabin)