Nice tidbit for those with barely any heat

[Aaronbrook37]

Just to be sure, you are blowing the heat out of the defrost or floor correct? You know that only cold blows out of the vents correct?

Yes. I've tried every setting. Could it be possible that the pulley/string/wire/cable connected to the heat thing has just become disconnected? It feels like it's doing nothing at all.

[neanderpaul]

Nice tidbit for those with barely any heat

Yes it's possible. Trace the cables back.

[Aaronbrook37]

Will do. Any other thoughts on why it'd still be ice cold? I'd like to least have barely any heat like the majority of people with single stage thermostats... How hard is it to get at the heater core itself to check it out for leaks/clogs/etc? Do I have to pull out the whole dashboard? I should check out my FSM.

[crazyrog17]

Nice tidbit for those with barely any heat

If water flowed through it when you were flushing, it could only be a problem with the bypass pipe or return from the heater core

[Movin]

The cable on mine broke at the bottom where it hooks up. After your car is warmed up if you put your foot like normal on the throttle pedal the end of the heater core is by your little toe. If you feel the plastic in this area it should be warmer than other areas.

EDIT.. My 2 stage stat would only fit in the head one way..? Maybe some of these are built differently? I really doubt there are casting differences in our heads.

[Aaronbrook37]

Mine's a B6T head with a B3 thermostat, so I can't say for certain about the fitment of the thermostat necessarily. What I do know is that my cable is messed up on that bottom thing. Down there, once the car is warm, it's certainly toasty on the plastic... so that's a good sign. The cable... it is simply too slacky to pull properly in the direction I assume is hot/heat. Here are some pictures and drawings to try and sort it out.


Is this first picture in the cold position? If so, my cable is currently in the max heat position and it is just fitting nicely. This could explain my problem.


Is this second picture in the hot position? If so, my cable is currently in the max heat position and as you can see, it's nowhere near tight enough to pull that high. In this position, I did get moderately lukewarm air coming through the defrost/floor.

If I've found the hot position successfully, I'm happy to just leave it there all winter.

[neanderpaul]

Nice tidbit for those with barely any heat

There is a metal clip that holds that cable housing in place. You can see some rust residue on the cable housing where the clip used to be, where it should be. Get that secured and that should solve your problem.

[Aaronbrook37]

Retaining clip as in that one in the picture pointed to? Couldn't find the damn thing for the life of me! Or did you mean something else? Can you whip up a drawing in MS Paint to what you are referring? I don't quite understand.

[neanderpaul]

Nice tidbit for those with barely any heat

In order for the cable to actuate the heat the housing of the cable must be immobilized. That will allow the cable to move back and forth inside the cable housing. You might be able to use a zip tie if the clip is gone. While the cable is off you could actuate that heat switcher by hand to see if your heat works. And for a temporary fix you could just turn the heat on there.

[Movin]

In your first pic right at the tip of the hot arrow is the plastic that should have a spring loaded clip to hold the housing of the cable, just like as stated above. Wiggle the door back and forth a bit to make sure nothing is keeping it from sealing the cold off, like any little thing that could have come down a vent.

[Aaronbrook37]

I think I found said clip. Now the cable is in the hot position, and the door is in the hot position I believe. I am now getting some heat (air is lukewarm) through the floor and the defrost. However, I can hear lots of inert rustling (like pine needles and junk) so I think there's a bunch of crap in front or behind the heater core that I need to clear out to get completely proper heat.

[Aaronbrook37]

Update: Flushed the heater core with alternating water, pressurized air, Simple Green to soak, and a good rinse and blow-out. Now the car blows hot air, albeit a little weaker than I'd expect it to. I still think the heater core isn't able to fully blow 100% of its air, but at least the car will be warm for my girlfriend now!

[bravekozak]

All Festivas without A/C have at least twenty years of dirt and dust plugging up the fins of the heater core. Those with A/C have the evaporator fins plugged up. It is a chore to lower the cooant level in the block, remove the dash, open up the blower housing to get at the heater core, blow it out with compressed air and then reinstall everything.
It is a lot easier to just remove the damper assembly behind the glove box. Therefore I recommend installing a cabin air filter so you never have to clean the heater core again, just to have heat in the winter! Be sure to hover your mouse to detect the hyperlinks in the old threads.

[Aaronbrook37]

All Festivas without air have at least twenty years of dirt and dust plugging up the fins of the heater core. Those with A/C have the evaporator fins plugged up. It is a chore to remove the dash and open up the blower housing to get at the heater core.
It is a lot easier to remove the damper assembly behind the glove box. Therefore I recommend installing a cabin air filter so you never have to clean the heater core again, just to have heat in the winter!

Well isn't a cabin filter rather pointless if my heater core is still plugged up with dirt and dust? There's no way I can get around it and blast it with compressed air or anything? That'd be really handy. I'll check out the damper assembly behind the glovebox tonight.

[bravekozak]

What I meant was to install a cabin filter after you have cleaned the heater core, so it doesn't ever get plugged up again. I wish I took a picture of my evaporator fins. I pressure washed them backwards to clear the sludge. A lot of members seem to think that the main culprit for lack of heat is the wrong thermostat. I believe most members will be shocked when they open up their blower assemblies. I hope members post pics of their filthy heater cores to this thread. Usually, the blower assembly is the last thing that is ever maintained. It's bad that there is no mesh on the plenum, to prevent pine needles and other large debris from entering the air duct. Everyone has a "heater core cabin filter". What is ironic, is that I have a heater hose bypass, since I do not drive my festiva in the winter. Yet, I still have my heater core installed just in case I ever change my mind. I would probably have super A/C if I removed it. This is good info for anyone in Florida. I don't believe a Festiva has a heater core electrical or vacuum shut off valve.