heat prob for expert not heat have checked a lot

[hundahunta]

does it get cold or cool???? is the ac clutch staying on....

[91sport]

yes still have one hot one cold hose as far as blocked core have ran water thrugh both directions with no dirt coming out

as far as broken/cracked door can hear it flopping back and forth with lever aand would think that i would at least have some heat coming out if it was that not to mention the one cold hose

if not familiar with this system two hoses come off pump/moter then go to two t"s one t goes to in on core and in on resivuor then the other t goes to out on core and out on resivour (reason for asking about wrong flow direct) wondering if flow bacwards would causethis due to sucking air from resivour causing pump to see air and stopping flow seeing it as crack in core

as for the revese pump if it is on a moter with v belts it turns one direction if using serpintine belt turns oposite have to get right one for what you have and wondered if they installed the wrong one before i got it ( i would have replaced it myself ) would reverse flow cause this and not cause an overheating problem with moter because moter runs fine and cool

also no valve in hoses have went to jyard and seen one on one there but all i have is the vac line hanging close to where it prob should be as i said been rigged before i got it looks like valve was removed or cut off the t it was on on the one in the yard all i see this doing is giving it full flow all the time which should make it extreamly hot like the resivour hooked up to the same lines and i know this makes it sound like a clogged core but i"ve check it and it's got flow and no cracks checked both

now you see why i'm confused and looking for stange things that might be causing this

oh ya ac not working

[91sport]

also have burbed the system several times each time a line has been broken after system has heated up

[DIVERHERB]

I dont understand why one of your hoses is cold. Have you taken off the return hose while the engine is running to make sure that the hose has not been blocked off internally? That year there should also be a heater valve on the hose. If there is an uncapped vacuum hose the blend air door will not work as it is vacuum operated and those diaphrams will not work if there is a vacuum leak anywhere in the system. Those earlier years also had two different water pumps available. One clockwise rotation and the other counter clockwise, but that should show up with an engine cooling problem, i.e. running hot at speed. But all being said if there is flow then you should be getting hot water out of both of the heater hoses. Dumb question but is the engine reaching normal operating temp.

[91sport]

blend door is cable ran have seen the cable and lever moving as i adjust temp control

no there is no valve in the lines looks like it was removed before i got it has the t pipes but no valve looks like it was cut off and hose reatached with hose clamp

did answer about pump was wondering about if revese flow being able to keep engine cool or not

and yes temp is running from just below 210 to just above 210 changed stat just to make sure that was not it

and with the resivour getting hot i don't understand why i don't have flow though core that is hooked up to the same hoses

also when i flushed out core to check flow i used the heater hoses to do this just clamped resivour hoses off wile doing this to check hoses at same time

[DIVERHERB]

Sorry you are right, vacuum operates modes heater is controled by cable.
I have worked on these things for alot of years and seen alot of things but your jeep does not make sense. The one thing that I cannot grasp is if you have flow both of your lines should be hot, one a little hotter than the other but still hot. You have disconnected the output from the heater core with the engine running and you have output right? You can do this by running a water supply back to the engine through the disconnecte hose.

[inafogg]

hey 91sport what engine i didnt see it posted??was looking at the 6cyl it looks to
have 4 hoses to/from.just want to make sure the info is correct.you may want to
put the valve in & back to original set up. or is it a 4cyl??

[chrisl757]

91 sport, I am far from an expert here, but I read your description of the T's very closely. It seems that what happened at some point is that your heater control valve was replaced with some t's, and rather than cap off the T's, there were hoses that now run into the reservoir (overflow tank).

I'm not sure how that could be rigged without drilling into the reservoir tank, or just keeping the cap open and pushing two hoses into the reservoir.

Anyways, if that is what has actually happened, I would say to remove that end of the T (the part that goes into the reservoir). Based on the way you describe it, you have a parallel flow path for the coolant to completely bypass your heater core (hence no heat in the cabin).

You could remove those hoses that go into the reservoir and cap them off. If you don't have caps or plugs for them, go to a hardware store and get some caps from a garden hose repair kit (which should fit fine), and cap them off.

Might only be a $1, and what you'll basically be doing is finally forcing the coolant through your core.

I post this hesitantly, because I know little compared to most of the guys on here, so if I am off base, someone correct me.

[captan]

Did anyone consider that maybe the air vents in heater core are clogged. If mice got into the vents and build nests that can block air flow through the heater core and still get some air through it. Also is there flow coming out the heater hose? Just a thought.