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I was getting warm air coming from the blower, so I decided to replace the thermostat. I filled it up with pre mixed anti freeze, and figured that would do it. But nothing has changed, its still warm at best. I let the jeep run for a while and looking at the water in the radiator, well it doesn't turn over like I thought it is supposed to. In fact it just sits there and gets hot... Isn't it supposed to circulate?
well in any event does anyone know what it could be?
 

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I was getting warm air coming from the blower, so I decided to replace the thermostat. I filled it up with pre mixed anti freeze, and figured that would do it. But nothing has changed, its still warm at best. I let the jeep run for a while and looking at the water in the radiator, well it doesn't turn over like I thought it is supposed to. In fact it just sits there and gets hot... Isn't it supposed to circulate?
well in any event does anyone know what it could be?
Ever had problems overheating on your jeep? Water pump may be going out.
 

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If you aren't having any overheating, it might be the heater core. My 94 pickup does luke warm at best.
 

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Two things can cause a luke-warm heater... a clogged heater core which is most likely, or a heater flap door that is not moving which is often caused by a vacuum leak or a broken vacuum motor that moves the blend door.

My guess and the most likely problem is that the heater core is clogged. Disconnect the two heater hoses from the block where they connect and flush them back and forth with a garden hose. This should get rid of any gunk that is clogging the core and causing the heater not to get hot. The hottest hose will be the input side of the heater, the cooler hose will be the output side. Connect the hose to the output side first to reverse flush it. There is no valve to control how much coolant flows through the heater core, coolant always flows through it. How hot the heater gets is controlled by the air blend door inside the Jeep, providing the heater core is not clogged as is common.
 

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Two things can cause a luke-warm heater... a clogged heater core which is most likely, or a heater flap door that is not moving which is often caused by a vacuum leak or a broken vacuum motor that moves the blend door.

My guess and the most likely problem is that the heater core is clogged. Disconnect the two heater hoses from the block where they connect and flush them back and forth with a garden hose. This should get rid of any gunk that is clogging the core and causing the heater not to get hot. The hottest hose will be the input side of the heater, the cooler hose will be the output side. Connect the hose to the output side first to reverse flush it. There is no valve to control how much coolant flows through the heater core, coolant always flows through it. How hot the heater gets is controlled by the air blend door inside the Jeep, providing the heater core is not clogged as is common.
on 97 the heater flapper is controlled by a cable. when I bought mine it was snapped. OP try to look under the passenger side dash close to the center theres a rod connected to a cable see if its opening and closing fully when you move the slider side to side.
 

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on 97 the heater flapper is controlled by a cable.
Absolutely, that control wire came off my '97 TJ's door which caused it to not heat all that well. I forgot that, it was only with later model TJs went to a motor to control that blend door instead of the control wire used by the '97 and maybe the '98 too.
 

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I'm with Jerry.. I have a 97' Sport with the 6cyl and my heater was warm at best last winter. I flushed the heater repeatedly for about a half hour, and now it rocks. I first changed the thermostat and fluids and that did not help at all. I flushed it for a few minutes, that didn't help. I flushed it "really" good and now the heat is really hot.
 

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on 97 the heater flapper is controlled by a cable. when I bought mine it was snapped. OP try to look under the passenger side dash close to the center theres a rod connected to a cable see if its opening and closing fully when you move the slider side to side.
SO after an hour of flushing the core and watching it come crystal clear, I backed out the jeep and started it up. heat was still sub par. so I checked what you said and viola....I now have hot heat. thanks for the input. the cable must be wore out. it moves just not all the way...:iamhappy:
 
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