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777 Views 12 Replies 6 Participants Last post by  LooseNut
For all those that helped, thanks. My Jeep is finally dialed in. It runs great. Anyone who wonders, the upgrades are; new fuel pump, vacuum lines, Carter BBD, Clifford cover, cored radiator, thermostat, and housing. Your basic upkeep/upgrade for winter. However I would like to get more heat. I have the Chevy blower upgrade, and have sealed the windshield frame, with foam, but the heater is not kicking a lot of heat. Why? I am running a 195 thermostat, which should be good heat, but it’s not! Is my heater core bad? Does anyone know how to get higher temperatures out of this set up? This is an 85 CJ7 258. Please any suggestions and help would be greatly appreciated!

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i would check all the different heater cables and make sure they are all functioning properly. the cable that activates the heater needs
to be in the right place. for the first time since i have had my CJ the defroster actually works with my blazer motor. if you have any
warm air then it shouldn't be the heater core.


/wwwthreads_images/icons/tongue.gif I spent last weekend with my crack team of moonguys/wwwthreads_images/icons/wink.gif/wwwthreads_images/icons/laugh.gif/wwwthreads_images/icons/smile.gif making a riser to set a center console in our '79 CJ7. The riser starts out at 7" above the floor in the back, and tapers to about an inch over the floor wrinkle in front. In the rear of the riser(the riser is a flat-top tunnel 8" wide and 25" long) is a Hupp Heater I bought from Rosser Think Jeep. The water piping is under the floor and in series with my existing dash heater. The tunnel has outlets in the front corners to heat our little feetsies. Don't have it going just yet....waiting for a floor shift kit for the TH400....but it will be a big help heating our CJ./wwwthreads_images/icons/crazy.gif

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it could be your heater core is plugged up, do you get good airflow? if not check to make sure your heater box is not plugged up, make sure there are no kinked hoses going into the heater box, if all else fails take the heater core into a rad shop and have em flush it out. just cause you have some heat dosn't mean its good, could be just a few cores unplugged in it.

I don't know how cold you get, personally I walk around in short sleeves with no jacket down to about
45 degrees but... You might try pulling the heater core and washing it out, the air passages can get full
of dirt. Also make sure that the foam has not come loose from the deflector door and wound up against
the core. I found a grille cover that fits the CJ. It's made out of the same material as the tops and uses
snaps which install around the grille to hold it in place. I think it's made by K-line but I'm not sure.

I hope you have better luck in the cold with the Clifford than I did. If you have a lack of power for the
first ten minutes when the mercury drops below 30 and/or you get backfiring throught the carb, check for
the rocker arms scraping on the inside of the Clifford.

Someone out there has to know how to get more heat outta this unit! I think my heater core is plugged or bad, as the heater use to get hot, and now it is just warm. Is there a way to put in a larger heater core? Something along the lines of the Chevy blower motor upgrade for the heater core? I have this Chevy blower motor that puts out massive amounts of air, but I need the heat! Anyone?

Have you checked what has been suggested to you already? If you think the core is plugged, pull it out and take it to a radiator shop to check it out! Nobody can give you the answer without you doing a little leg-work first. A heater core should cost less than $50 if it is bad.

If your heater worked before you did all your engine modifications I would suggest that you double check that you thermostat is
working the way it supposed to. Just because it is new does not mean it works. Another thing you can try is to put something to
block the air flow to your radiator partially like others suggested.
Good luck,

What is the easiest way to check if the Thermostat works?

First of all do you know how many degrees it is? If you want to test when it opens remove it, throw it in a pot of hot water on the stove and keep raising the heat till it opens. You need a good thermometer in the water the whole time. If you only want to know that it it working start your jeep cold. Before you do squeze the upper rad. hose. You should be able to squeeze it closed most if not all the way. Then fire her up. After 5-15 min squeeze the hose again. It should be hot and hard to squeze. Have fun, Andytron 89XJ 4.0 5-speed

I know I can't get heat if the outside vents are open check to be sure the cable and vents are operational,you can check the outside vent doors by removing the little grill in front of the windshield,I know my vent cable is a SOB I have to use pliers to move it in or out. I had to fabricate all the valves in the heater box when I had it apart for the blower motor upgrade also lubricated all the cables,removed all the leaves and debris .

Learn to let go of what does not serve you ,but forces you to serve it
Like Andytron was saying you can through your thermostat in a pot of water. When the water reaches the approximate temperature
that the thermostat is made to open, it should open. If it does not then the thermostat is not working. In the past when I have even
suspected the thermostat I just go ahead and replace it, as they are under $10. The reason I suspect that the thermostat could be
bad is that it sounds like your engine is not building up enough heat to heat your jeep. This overcooling could easily be caused by
a thermostat that is sticking open.
Good luck,

1. Check to see that your temp cable is actually pulling the lever all the way open. It's in the middle under the dash.

2. Does your temp gauge go up? It should go about 1/3 of the way up if the thermostat is working.

3. Put your hand on the heater hoses where they go into the heater core. They should both be hot if the water is getting through.

Loose nut behind the wheel
Another right-wing conservative.....
Born and raised in Jeep-Town
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