Topic: heating efficiency

[stan98tj]

my softop and soft windows sure dont insulate well this much i know. my heater seems ineffective at any temp under 40*. if i have the blower on above the 2nd level, it blows cool air through. i basically have to keep it at level 1 or 2. is there anyway (within reasonable cost and labor) to increase the heat temp coming from the vents, or would it be easier to go the way of an auxilliary heater? the one sold by quadratec mounts in the back, but i think it requires the back seat to be removed, which i wouldnt really want to have happen.

[sharpxmen]

my softop and soft windows sure dont insulate well this much i know. my heater seems ineffective at any temp under 40*. if i have the blower on above the 2nd level, it blows cool air through. i basically have to keep it at level 1 or 2. is there anyway (within reasonable cost and labor) to increase the heat temp coming from the vents, or would it be easier to go the way of an auxilliary heater? the one sold by quadratec mounts in the back, but i think it requires the back seat to be removed, which i wouldnt really want to have happen.

shouldn't blow cool air - I would start by looking at the thermostat as it could be that it remains partially open. I do feel that my Jeep is colder inside due to the softtop, but the air is coming out quite hot even on very cold days. Could also be that the heater rad is not getting enough flow somehow (maybe plugged? - did you ever had any leak fix powder put in your cooling system, that can cause the heater rad to plug some of the cells).

[stan98tj]

shouldn't blow cool air - I would start by looking at the thermostat as it could be that it remains partially open. I do feel that my Jeep is colder inside due to the softtop, but the air is coming out quite hot even on very cold days. Could also be that the heater rad is not getting enough flow somehow (maybe plugged? - did you ever had any leak fix powder put in your cooling system, that can cause the heater rad to plug some of the cells).

it's not exactly cool..just not as warm as the first or second blower levels. basically at high fan speed it blows cooler air. im not sure if thats normal, given the fact that its a jeep and the heating system isnt a climate control wonder. the air comes out hot on the lowest fan speed, and decreases as you increase the speed. ive never put any leak fix in..dunno if the prev owner did or not. How hot is hot though? im not even sure as to what heat temp im to expect given this my one and only jeep and ive had no others to compare it to.

[aw12345]

Even though I am in So Cali, I have had the Jeep in freezing temps and the heater works like a charm regardless of the speed of the heater blower. If the thermostat is good then the heater core is restricted. You can try to flush it both ways with a garden hose, if that is no dice then it's time to replace it. Since it's plenty hot at low speed it should not be a blend door, but just lack of coolant circulation through the heater core

[sharpxmen]

it's not exactly cool..just not as warm as the first or second blower levels. basically at high fan speed it blows cooler air. im not sure if thats normal, given the fact that its a jeep and the heating system isnt a climate control wonder. the air comes out hot on the lowest fan speed, and decreases as you increase the speed. ive never put any leak fix in..dunno if the prev owner did or not. How hot is hot though? im not even sure as to what heat temp im to expect given this my one and only jeep and ive had no others to compare it to.

on max fan speed on mine it's quite hot on the output by the feet (can't keep my hand there once the engine is hot) and very warm on the defroster output (i'm not showing off or anything) - but i cannot remember if that was the case in really cold days also, in any case it is quite warm on those days as well, my prob is that cold air is coming in around the zippers and velcrow of the softtop rather, so it's blowing hot from the heater and blowing frost from the softtop, not a good combination :)

what is your engine temperature at?

maybe someone here that had a similar problem can give some pointers on what the issue could be, i only adjusted the cables once and had a custom instrument panel installed so i took it out and cleaned the controls but other than that i didn't do much with it so unfortunately i can't be  of much help.

[aw12345]

On a TJ the heater doors work with vacuum, but since it blows hot on low speed my money is on poor circulation through the heater core or a bad thermostat lean towards the first though

[stan98tj]

On a TJ the heater doors work with vacuum, but since it blows hot on low speed my money is on poor circulation through the heater core or a bad thermostat lean towards the first though

ok art, how do i check for the poor circulation through the heater core?

sharpxmen, my engine runs at around 207, 208...dunno exactly but it's under 210.

[sharpxmen]

ok art, how do i check for the poor circulation through the heater core?

sharpxmen, my engine runs at around 207, 208...dunno exactly but it's under 210.

that's fine as far as the temp goes. check if the cables are adjusted properly too - i remember when i did it that it wasn't closing or opening the whole way and that improved the heating but i cannot remember exactly what i did as it was quite a while ago

[stan98tj]

that's fine as far as the temp goes. check if the cables are adjusted properly too - i remember when i did it that it wasn't closing or opening the whole way and that improved the heating but i cannot remember exactly what i did as it was quite a while ago

would you be able to elaborate on the cables im looking to check?

[Castr8r]

How long has it been since the thermostat was replaced?  You should have a 195* t'stat, and I'll bet you'll have good heat.  When you replace it, go with a quality part; it'll be cheaper over the long haul.  (I found this out the hard way!)

[sharpxmen]

would you be able to elaborate on the cables im looking to check?

you have a TJ and i am not familiar with it.
what i did on mine was to move the controls all the way left and right and make sure the doors (on the heater unit) are closing all the way - on my YJ there is a little metal clip on the cable jackets that secures them to the heater housing, it's easy to unhook that and adjust - but like i said, i did this about 4 years ago and cannot remember exactly which is which to give you specific details and most likely in your case the heater housing is different also.

[TrailsLessTaken]

You don't have cables on yours since its a TJ.  Yours is controlled by the vacum and you would have to follow the lines to see where they go to.  I would try unhooking the heater core on the firewall in the engine bay.  You should have two hoses that go in to it, and use a garden hose and try to flush it each direction.  That sounds like thats all the problem is, is that it cant generate enough heat on the high setting cause not enough fluid is getting to it

[Got Wood?]

On my 97 TJ the door that controls the door for heat/cool is controlled by a cable, vacuum controls where it comes out though. There is a cable that comes out from behind the dash on the passenger side, on the left side of the passengers foot area, above where your left foot would be when you are sitting in the passenger seat there is a cable that is attached to the arm for the flapper. On my old TJ the part of the cable that is attached to the outer sheath which then attached to the heater box was broken and so the flapper door didn't seal all of the way, when you turned the blower on hi the pressure would push the door a little so you didn't get full heat, I repaired the clip on the outer sheath and my heat seemed to be a little hotter. I am not sure this is the same problem you are having but it helped mine. Flushing your heater core is a good thing to do anyhow, I would start by putting the hose on the output to dislodge anything in the core, but I would flush in both directions.

[sharpxmen]

On my 97 TJ the door that controls the door for heat/cool is controlled by a cable, vacuum controls where it comes out though. There is a cable that comes out from behind the dash on the passenger side, on the left side of the passengers foot area, above where your left foot would be when you are sitting in the passenger seat there is a cable that is attached to the arm for the flapper. On my old TJ the part of the cable that is attached to the outer sheath which then attached to the heater box was broken and so the flapper door didn't seal all of the way, when you turned the blower on hi the pressure would push the door a little so you didn't get full heat, I repaired the clip on the outer sheath and my heat seemed to be a little hotter. I am not sure this is the same problem you are having but it helped mine. Flushing your heater core is a good thing to do anyhow, I would start by putting the hose on the output to dislodge anything in the core, but I would flush in both directions.

great post - that's one thing he should look for. My cables were still attached but were not closing all the way so had to adjust them so sort of similar problem

[stan98tj]

Good stuff! thank you guys, ill try and find myself a little wedge of time and get on that, ill post when i have results.