DangerXJ

I have 2000 xj. 105K Did the head, thermostat, clutch fan, water pump and new radiator. I flushed the heater core backwards and forwards I let some prestone coolant cleanser In it for twenty minutes and rinsed again multiple times. Did this all end of august and now as I fears still not hot enough. I am going to try using compressed air and see how much this helps.


So I finally have some time to screw with my jeep and will attempt to do the compressed air; but more reading and thinking has me wondering about the blend door. I dont know much about it but from reading it looks like there may be a door not quite open/closed all the way? How do I access this?

The fan blowers works and operates on all 4 different speeds, the heat function will blow through the floor change to both floor and dash as well as transfer over to defroster mode - so the air is moving its just cold!! I live in VT and thankfully its a mild winter but its cold. When I drive I leave the heat on 1 and floor and it blows small amount on my feet and if need be I can switch it over to floor/defrost. If you turn the blower up any faster the air does the opposite it's intended to and you feel cold where as with it on setting # 1 it is better than having it off!

Any help with screwing with blend door before I pull out my heater core and swap it.

DaddyCat

I would advise against the use of compressed air, you could damage the heater core. If the water flowed well when you flushed, the core is not blocked.

When your jeep is fully warmed up what temp does the dash gauge show? It should be ~200 F if not you may have air in the cooling system or a bad or incorrectly install thermostat. 195* is the correct thermostat. Some times you can rev the engine a few times and clear out any air bubbles.

DangerXJ

The truck comes up to temperature at a decent rate and reaches the hash mark before 210 I believe is right around 195 200.

When I installed the coolant I poured it in not only from the radiator but used the highest point in the system top of the thermostat housing to fill the coolant up with no bubbles. I have driven it for several weeks and checked to ensure I still had enough in there as well as tried to top it off and the system was full.

I have a new heater core sitting on my passenger seat right now I just want to cover all ends before I tear apart the dash.

I don't have any coolant leaking in the passenger compartment or anywhere else that I can detect; I do sometimes smell a slight sweet antifreeze smell from time to time in the jeep.

Before I did all of the work to the cooling system I had been batteling with the system for atleast a year or 2 in trying to get and keep the coolant clean. I would flush it and flush it and have it done at a shop and do it at home and could not keep it clean it would have brown sediment in it. It ended up going through one or two water pumps and having issues with dirty coolant and it not cooling the truck properly (couldn't use the jeep to tow anything with for extended periods of time). The radiator ended up cracking and spewing coolant while i was driving and boiled over and warped the head hence the rebuild. Included all of that just to paint the picture a little bit more; the heater core is the only thing that hadn't been replaced.

Any help or more thoughts / does anyone know about the blend door? My thought is maybe its not moving to the warm position and still letting in the cold air??

Just doubled checked let the jeep warm up and took it for a 5 minute trip with the vehicle coming up to temp as well with the "heat" on as far red as it can be as well as blower on the highest setting. The air got a little warmer as the truck warmed up but was no where near blowing effectivly hot heat. I checked the hoses going to the heater core and the top hose is very hot where as the lower hose is warm but no where near as hot as the top hose........

Macoozie

The solution to your problem lies in a step-by-step analysis as outlined on numrous threads on CF.

But, for openers . . . do yo have HOT coolant in the hoses both in and out of the heater core at operating temp? Then check the vacumn controls for the mode doors. Usually one of these.

On your 2000, you have 3 doors. Door number one: blend air door for heat or a/c. Door number 2: floor/panel door. Door 3: Floor/defrost door. Check the blend door motor functionality on the face of the ac/heat box just to the right of the trans hump. It should rotate as you rotate the heat control.

The mode doors for vent vs floor and fresh vs recirc/defrost are VACUMN controlled. You know the vac bulb behind the bumper by the battery?

If you are getting HOT coolant into and out of the core AND the doors are functional, the only thing restricting the heat from the passenger compartment is a physical blockage in the heat box passageways.

kentuckyscott

Mine is doing the same thing except when I am driving it heats up hot....then when I sit parked it cools way down...any suggestions?

caged

there should be a small white plastic lever under the dash. check to see if that is moving.

i've read where someone actually cut into the housing to access the blend doors and moved them manually, then glued the housing back into place.

maybe this will work for you for now...

DangerXJ

now my thought process is more along the lines like something is wrong with this door or the blend; when i move the heat control **** from blue to red it seems like it moves "very freely" almost like its not connected to anything. will investigate in the evening on saturday.

DangerXJ

There should be a small white plastic lever under the dash. check to see if that is moving.


where abouts is this lever you speak of?

caged

ok, it seems yours is different.

check this out. http://www.jeepforum.com/forum/f9/ho...repair-464741/

and this. http://www.heatertreater.net/jeep-cherokee-97-06

wifin

Can broken blend doors also effect not having any cold air? I did a recharge with dye, no leaks anywhere, the compressor is brand new and works, the evaporator works. So I think it would be the blend doors. When I turn on the heat, it works perfectly, when I turn on AC is doesn't change temperatures when I turn from the blue to the red, just stays the same.