VARG7

hi i got a 1990 jeep cherokee 4.0 4x4 my heat is not workin hot jus barley warm is there any known issues?? i see a valve that goes to the heter core, is that replaceable or is that common on these??

please help im freesing my azz up here in ri lol

chrisl757

and I've been working on this issue for weeks. Happy to help.

Some basic questions:

What is your temperature gauge reading on your dash? If it is around 210, then your thermostat is good. If not, then you might want to look at a new thermostat. THEN....

look under your hood for the two heater hoses that are going into the firewall on the passenger side. reach onto them and see if they are both hot while you have the engine warmed up with the heat on.

If they are both hot, then you are likely getting good flow through your heater core. If they are not hot, or if one of them is not hot, then your core might be clogged and need a flush (which is easy to do).

You can look on here to see some other examples of how to do a heater core flush, but a garden hose, some buckets and a screwdriver and pliers should be all it takes with about 10 minutes of effort.

Let us know how it goes.

VARG7

Its got a new water pump ant t-stat. and flushed it with come air a couple weeks ago it seemed pretty clogged i pushed it through and the heat got better but still sucks.. im gonna try the hose flush today when i get outta work ill let u know how it works

chrisl757

make sure you flush it both ways.

I went to Benny's and got garden hose connectors for $1.59 each. One female and one male. These are the kind you would use if your hose got cut and you wanted to splice it back together. anyways, pull the hoses from the core at the connection point where they connect to the heater valve. Then put your male and female garden hose connectors in there. Then I hooked up the garden hose to one, and ran a drain hose to the other (for the drain hose I used the hose line from my dehumidifier---works just as well and I ran it into a bucket so I could see the crud coming out).

The reason to do all this is that you will not spill as much antifreeze on the driveway AND you will get a better and more controlled flush through the core.

Take it easy on the hose pressure at first.

Once you flush it one way....swap the hose connectors and flush it the other way.

VARG7

ok well i tried to flush it but then i realised the hose was frozen lol so when puttin it bck together i checked out that valve and that was all messed up so i cut it out put it all back together and ran it for a lil and tada there is the heat i wanted lol

96Cherokee113

There seems to be a problem with the heater control valves in the Cherokees. I'm gonna change mine out on one of the warmer days before it craps out, so I'm not left in the cold, haha. Might as well flush my heater core while I'm at it. If you just ran the hoses directly to the heater core, you won't be able to shut the heat off because the coolant will be constantly running through the heater core.

auburn4193

im having this same exact problem with my 2000 4.0.. going to the auto parts store first thing in the morning!

captainwoot

The 2000 model does not a heater valve, wasn't that discontinued after the renix models ?or was it in 97?

milmat1

CORRECT! Mine doesn't have one. What it does have is a Temp control servo under the passenger side dash. It is a small servo that adjusts the door in the plenum, between Cold--hot.

When you turn from Hot to COLD does the air temp actually change at the vents???? If not the air control servo may have failed. Mine did !

It is mounted vertically under the pass side right up against the tranny hump ! And any Cherokee or GC that has a rotary temp control **** uses the same one.. However you need to re-use the little plastic drive gear from YOURS !....(ask me how i know !!)

VARG7

ya the whole shutting the heat off dont bother me for now lol when summer comes ill worry about that, for now itll be fine its cold up here lets jus try to make it through the winter first. on most other cars it always runs through the heater core all the time thats y there is the hot/cold lever i dont see the puropse of that valve

auburn4193

the temp. does change its just not very warm. i figured out after i made the first post that the 2000 doesnt have the heater control valve. it should be above freezing by this weekend here in alabama so ill flush it. if that doesnt work i might try putting a piece of cardboard and covering half of the front of the radiator as i saw suggested in another post.

stuntz87xj

i have the same problem with my 87 xj, very little heat, however, i am having some other issues as well and was wondering if they may be related.

1st, my temp gauge barely registers temperature at all. it was reading in the summer, but usually very very low (110-150) which is obviously impossible. I recently changed the thermostat and did a coolant system flush, however i did not directly flush the heater core.

2nd, i only have use of the high setting on my control panel.

3rd, i only have use of the defrost setting on my control panel.

I wonder if these things could all be linked to one problem, however, i did have a leaky windshield at one point (blew 2 cd players) which is now fixed and i thought that might be the cause of the control panel issues. anyway, just looking for some feedback. thanks

mobbs

Check your blower motor resistor for problems 2 and 3. Sorry to revive an old post.

kylelangereis

ive got the same problem on my 2000 cherokee. The motor gets up to 210 but no heat. Both hoses to and from the heater core are hot and i did a heater core flush but theres still no heat

Firestorm500

Then you probably have a blend door problem.