Heater not getting hot

[paulscooter]

I live in the high country in Arizona, (a mile high) and we get snow and cold weather here. We had our first light snow of the season so I took my 1999 TJ out for a ride on the dirt roads in the mountains. The heater was just putting out warm air, not hot air. So the cab never got warm. The thermostat seems to work ok, keeping the temp gauge just below mid point, about 195 I'm guessing. I pulled the Jeep over to the side and popped the hood to check to see if the Air-cond compressor is running and it's not. It is a soft top so it's not a perfect seal, but i don't have any trouble with the air-cond keeping the cab cool. It just seems the air coming out of the heater is not hot. I rotated the heat know from cold to hot and it seems to work,, it gets cold and then warm but not to the point of being hot.
Any ideas?

 

[Only TJ's]

Have you checked your blend door to make sure it's operating fully?

 

[Jerry Bransford]

If your temperature gauge is only showing 195 degrees, its supposed to be at or very close to 210 degrees, either someone installed the incorrect thermostat or it's stuck open. The thermostat needs to be a 195 degree model, that's what the computer is programmed around. Modern engines run more efficiently at hotter temperatures, installing a 165 or 180 degree thermostat would be a mistake for a Wrangler. A good brand would be a Stant or Murray. I personally like the Stant SuperStat model. Make sure whatever you buy is NOT a "failsafe" thermostat which commonly gets stuck in the open position so the engine can't warm up.

But the heater should still be hot with the engine showing 195 degrees. I'd guess the heater core is plugged with gunk. You can use a garden hose to flush the heater core. The hoses have two different diameters so note which hose goes where then disconnect the heater core hoses and flush them back & forth with the hose until the water flows freely through it.

And it could also be cause as suggested in the post above. But do at least get your engine thermostat replaced with the right 195 degree model.

 

[paulscooter]

If your temperature gauge is only showing 195 degrees, its supposed to be at or very close to 210 degrees, either someone installed the incorrect thermostat or it's stuck open. The thermostat needs to be a 195 degree model, that's what the computer is programmed around. Modern engines run more efficiently at hotter temperatures, installing a 165 or 180 degree thermostat would be a mistake for a Wrangler. A good brand would be a Stant or Murray. I personally like the Stant SuperStat model. Make sure whatever you buy is NOT a "failsafe" thermostat which commonly gets stuck in the open position so the engine can't warm up.

But the heater should still be hot with the engine showing 195 degrees. I'd guess the heater core is plugged with gunk. You can use a garden hose to flush the heater core. The hoses have two different diameters so note which hose goes where then disconnect the heater core hoses and flush them back & forth with the hose until the water flows freely through it.

And it could also be cause as suggested in the post above. But do at least get your engine thermostat replaced with the right 195 degree model.

Thanks for the quick answer. I was just making an estimate on the temp gauge. It is about 1 or 2 needle widths away from the 210 degrees mark. The jeep is 22 years old with 82k miles and was sitting around for a few years. I been doing a LOT of work on it including flushing the cooling system. I think ( not sure ) I flushed the heater core also. Someone put one of those flushing kits on it. The one with the garden hose adapter connected to the heater core on the out side. I flushed it out with the garden hose until it ran clear. Then I bought 10 gals of deionized water to get out most of the tap water. I then drained out half the water and filled it up with anti freeze. I'm not a mechanic, but really enjoy working on it.

A short list of the things i did to it over the past 6 months. New tires, new shocks, new steering dampener, new sparkplug wires, new rotor, new rotor cap, new airlifter, new double din Atoto radio, new sliding glass doors, I'm sure there's more i forgot. I have the hood gas filled hydraulic hood assist on order and seat covers on order. I AM HAVING ALMOST AS MUCH FUN WORKING ON THIS AS I AM DRIVING IT.

 

[Only TJ's]

It's fun until it's more time working on it than driving it