[92wrangler]

Hey guys I just put a new thermostat in my jeep thinking that that was the reason i was not getting very much heat but it did not solve the problem very much it went up a little bit but not very much does anyone know why i would not be getting much heat the jeep does not run anywhere near 210 and was wondering what it could be before i take it to the stealership thanx

[ScotZ]

Low on coolant.

Check and make sure your heater flap is actually moving. You can move it by hand by the passenger side foot compartment.

Bad waterpump

Bad thermostat( remove it completely and let the engine get warm. you should still get heat if the ambient temp is not too cold)

Blockage in the heater hose or core.


Just a few things to check. Hope this helps

[92wrangler]

I put a new thermostat in from the factory and i checked if the heater controls where actually moving and both were so i guess the next thing to check would be the water pump how would i check if that is bad or not thanx

[BPAGS11]

I have had the same problem in the past... Unfortunately Jeeps built around our time frame don't have the most powerful blower motor's to pump out enough hot air. I live in sometimes cold weather, so I opted to do a blower motor upgrade, taking the motor from an 88 GMC jimmy and swapping it out for the Jeep blower motor. It is a simply install, you need to bore out the motor hole a bit wider to accomodate the jimmy motor. Something to think about if your sick of freezing your toes off

[sentinal02]

Originally Posted by 92wrangler

I put a new thermostat in from the factory and i checked if the heater controls where actually moving and both were so i guess the next thing to check would be the water pump how would i check if that is bad or not thanx

if the jeep is running cool, then your water pump is fine. if it was bad then you'd know because your jeep would overheat. my uess would be a blockage in the heater core, either inside the coolant loop or dust build up on the air side in the heater housing. either one will rob you of heat. pull the hoses off the fire wall and back flush the core with a hose. see if that helps. if not, you're going to have to replace the core or blow out the fins in the housing. both require removing the housing so start with the flush.

[Mr. Notorious]

There's a possibility that you might have gotten the wrong thermostat. If I watch my gauge, it will go up to 210 then it opens and then my temp goes back down again. Lets me know its working properly. Maybe yours is stuck open for some reason? Next time you're on a highway, watch your gauge as much as you can. See if the temp goes up to a certain temp and then goes back down again. I always thought this was normal, maybe its just my vehicle. Good luck.

[cjb7804]

Don't rule out that flap in the heater housing. Mine has the same problem, and its my flap is letting a little bit of cold air in. Move the lever by hand on the heater housing on the passenger side, and feel your defroster duct (or heater duct) to see if it heats up. You might have to just kinda jiggle it a little bit. I can just move mine about a 1/4", and feel a huge amount of difference, but my cable and part of my assembly is broke, so thats why mine is acting up. Need to change out the whole housing with mine.

[92wrangler]

how would i go about back flushing the heater core have never heard of that before thanx

[JayJEEPguy]

How's the radiator look?
Mine was very corroded on the outside and the inside...open the rad. cap and look inside. If it;s all white and crusty looking on the inside of the radiator...time to replace.

My heat works great now.

[92wrangler]

I'll look at that today and see if that could be the problem i don't know though because it's almost new and i recently did a anti freeze flush

[BigSkyYJ]

Heh. I was going to start this thread myself this morning, but can't say I'm surprised someone beat me to it. Over the weekend, we had an arctic system move through the Montana area, bringing lows to -23F at my house. Thankfully, the heater was cranking through that period, and I thought was doing so fairly well. One the way to work this morning (mid-20s) it didn't seem to be getting any warmer, and I discovered that it was blowing pure cool air.

I know it isn't the water pump, as that was replaced by me a few months ago when the seal failed. It runs at the normal operating temps, and heats up to it in a typical amount of time, so at least I can rule that out. The coolant is good, being only as old as the water pump (70% of it was replaced, only a portion was recycled, and the radiator is <1 year old and was replaced not long before I got it.

Now, I'll try flushing it this weekend to check for blockage, but if this fails, how much work is required to make the core accessible in order to clean the fins or change it out? This is a poor comparison, but when my buddy replaced the core in his Taurus, he had to completely disassemble the entire dash to get to it.

Also, would the likelihood be more that the flap thing mentioned might not have something to do with it. I have noticed quite a bit of cold air coming in there, and seems to be sticking a bit. I have trouble getting the airflow completely to 'off', and it wants to stick on heat, more than anything. I'll run out at lunch and take a look, but any other input would be appreciated. I'd like to know now if I get to spend Sunday bent over the fender ripping the back half of the engine apart.

[EABiker]

The heater core on these beasts is very easy to replace (relatively speaking!). If the radiator has been replaced, chances are that the heater core had the same problem . If a reverse flush does not help, its time to replace! Do yourself a favor, and buy new heater hoses, (upper and lower are different sizes; cut a sample from each, and buy 3 feet of both!). Just cut off the old ones to save time and effort. The hosing unbolts from the engine compartment side, and the whole box can be pulled out from under the dash after the cables and ducts are removed. Be sure to re-fill the system with anti-freeze through the heater hose; that way you can eliminate an air bubble in the system. Takes less than two hours start to finish, and worth every minute!
E

[NIUPonyBoy]

I am putting a new blower motor in mine as soon as I correct the rear end issues. She is an oven when stopped or low speeds and she is damn frozen wind tunnel at highway speeds. bbbrrr Good luck.

John

[Wif]

Originally Posted by BigSkyYJ

Heh. I was going to start this thread myself this morning, but can't say I'm surprised someone beat me to it. Over the weekend, we had an arctic system move through the Montana area, bringing lows to -23F at my house. Thankfully, the heater was cranking through that period, and I thought was doing so fairly well. One the way to work this morning (mid-20s) it didn't seem to be getting any warmer, and I discovered that it was blowing pure cool air.

...... .

Just remember when you're driving thru -23F air you are super-cooling your rad (and the water flowing thru it). I guess with the added wind-chill it would be more like -40ishF. Does it seem warmer stood still ? Also check the viscous fan. If it is siezed up the air would be pulled thru at all times .. even when cool, adding to the cold air flow.

[BigSkyYJ]

I'll check it out tonight, but part of what I said probably came out wrong. It was in the mid-20s ABOVE zero this morning, with weather marching steadily into the upper 40s to mid-50s this week.

The flap is the thing I'll be looking into at lunch, but may let it run long enough to warm to operating temp and see what happens.