1997 Foor F-150 heat problem 4.6cu.

[Jeremy airjer W]

The thing is I hate the nuts and bolts. Give me a screwed up wiring problem and I'll dive in with no hesitation. Put a carburetor in from of me and I'll run the other way!

I'll post the latest thinker I had to deal with in a couple minutes.

[fishing tech]

I don't mind the wiring, but the new stuff working at a dealership and no one else other then engineers who say it should work, to get any info from.

I like when we call hotline and they have no idea but tell us let us know what you find.

Or they say replace this, if that doesn't work replace this, if that does work....

When you have a brand new vehicle that has less then 1k miles on it and the radio quits or the lights flicker it stalls and restarts. and these would be intermittent. Oh it can ruin a week.

Sorry didn't mean to high jack.

[x1957x]

I had a chance to change the thermostat and put in a 195 deg. OEM with no luck after that. STILL luke warm on panel and gets colder on defrost. I felt the heater hose and yes I cant keep my hand on the top one. To hot!, and the bottom one isnt as hot but hot. I can leave my hand on it. I changed the thermostatic controler with no success. How does that work? is it vaccum run? I am not convinced that it is the heater core. Because of the fact that the hoses are hot. Like I said I had a remote start put in a couple years ago and I was wondering if this could play a factor in this. I can try to run a water hose out to garage(in the cold) and try to reverse the lines and back flush it. Any thoughts yet? Thanks!!

[fishing tech]

If you were closer I would say bring it by, I am off work for another 6 weeks or so. My guess would be temp blend door. If the core hoses are HOT, the core should be also. So that makes me think that the blend door or motor is broke or it had a piece of the door foam stuck in it.

[x1957x]

Fishing tech.Thats my thought on the hoses. If the one was cold then I would understand the plugged heater core theory.. With that blend door in mind, I have changed it a year ago. I can put the control on air and also turn it down from the red to the blue and it does get cold. I also do hear it moving.. Being open a little bit like the foam thing. Can that make a big enough differance to do that? Where are you located at? Thanks again F.Tech..

[Scott K]

x1957, iffen I am a little closer to you, you could swing buy and I could take a look at it as well.

[x1957x]

Soooo! Here I go. Thanks guys for your input. I found out after all and everything that it was the heatercore that was plugged up. Heres how I unplugged it. I took off the hot(inlet) side at the motor and put on a 5/8ID. hose that was 2 foot long with a 5/8 coupler. I then took off the (outlet) side, the return side and after cutting it on a 4" straight piece of hose I clamped the motor side and proceeded to add the 5/8" hose to that. I made a shutoff valve for my air compressor so I could regulate the air as I BLEW out the heatercore. I went from the return side first and then to the inlet side and did this a bunch of times. DIRTY stuff! Then I clamped the return hose and added CLR ( calcium,lime,and rust remover) to it. This is the standard bathroom cleaner. I filled it all the way to the end of the hose and clamped it. I then changed the oil and greased the truck taking time. Maybe a half hour although I should have let it sit an hour and a half minumum. I took off the clampes and blew it back out the inlet and then the return a couple times and then I flushed it with water and kept blowing it out until I felt that most of it (CLR) was out of the core. Hooked everything back up and BINGO!! It really worked. Wouldnt believe the stuff that came out. Just should have let it sit another hour though. Maybe I might redo it again seeing how it was relatively easy and let it sit longer. What a differance it made!!! Thanks again guys. Thought I would let you all know. Think of the money I saved not having to put in a heater core!

[Macgyver55]

Careful what you use for pressure to clean it out. The radiator caps release pressure at around 16 lbs, so going too far beyond that you chance damaging the core. Yes, they will likely hold more pressure but depending on its condition you may end up going over the line. If its working good now...I wouldn't push your luck by doing any more.

[Jeremy airjer W]

Using CLR has popped into my head on many occasions but I have been to chicken to use it!