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Heat blowing warm not hot..

Tried cardboard in front of the radiator in case the engine was not getting hot during my commute to work. Made very little difference.

Anyone else have any ideas?
 
What may have happend in the flushing is that only part of the heater core was flushed. The water may not be circulating through the whole heater core. If 50% of the tubes are blocked, you will only get 50% of the heat. I would do the flush again going between input and out put until it runs clean. Then put a Cleaner/Flush agent in the system for the recommended time.

Once there is corrosion, it is hard to clean out. I am sure replacing the heater core is hard, but I bet it insn't near the effort that I am going through on my WJ! And I thought the Escort was bad!
 
I used a pressure washer on the heater core and it might have helped a little but not a whole lot. It's been around 20 degrees here the past couple weeks and I still have no heat. Both hoses coming out of the heater core are hot so I need some more suggestions if anyone can help.
 
Someone posted in a thread here recently with the same problem you have.

That poster replaced the heater core, then cut the old core open to inspect the tubes. The poster stated that all the tubes were close to 50 percent closed with crap. And this was after the poster had tried multiple flushes.

It may just be heater core time for you.
 
I just went through this on a 1990. I had the same problem, luke warm at best - hardly any heat when it was below 20 degrees outside. I had to replace the heater core. I also found a lot of debris in the heater door hinge area, including a screw that was (possibly) binding the door up - but that had nothing to do with the lack of hot air, the core was clogged up beyond Prestone's abilities.

Search here, there is a good write up with pics for the core - (changing the core isnt the problem, getting the air box out and back in is)

mixer door junk is here; I apologize for the ranting, I was an unhappy monkey

http://www.naxja.org/forum/showthread.php?t=1020640
 
I'm having similar things happening with my heating system and its been pretty freakin cold here in chicago. So I know my blower motor is working but the heat is barely on if at all. So I'm thinking of trying this heater core flush because before I had my transmission put in and they flushed the system my heat worked great. So I've heard a few different things on how to do this. So I can just take a garden hose and flush it though both heater hoses? Do I need the jeep running as I do this? My jeep is 90.
 
groovyjeepster said:
I'm having similar things happening with my heating system and its been pretty freakin cold here in chicago. So I know my blower motor is working but the heat is barely on if at all. So I'm thinking of trying this heater core flush because before I had my transmission put in and they flushed the system my heat worked great. So I've heard a few different things on how to do this. So I can just take a garden hose and flush it though both heater hoses? Do I need the jeep running as I do this? My jeep is 90.
Click to expand...

I'd pull the hoses off the core (carefully) and flush/backflush it out. You aren't going to push stuff through the core but you might be able to flush it back out the way it came in. I've done it on mine when I got it but also used some shop air. It was enough to get 150* at the floor on high blower (milder temps here though).
 
Jeep not running. You are just flushing the heater core here, right? Remember that the radiator cap is 16 PSI and that is what the heater cores are leak tested to when new. So--------don't pressurize it too much. Flush back and forth with water, or maybe let some coolant system cleaner soak in there for a while. Make sure to get antifreeze back in there good. You are probably as cold as we are.
 
Haha yeah its been pretty cold. I just moved here from Oregon and I got to say I'm missing there winters. Anyways alright I'll give that a try tomorrow since its suppose to be warmer tomorrow. Hope this works it would be nice to have heat again.
 
Txakura said:
I just went through this on a 1990. I had the same problem, luke warm at best - hardly any heat when it was below 20 degrees outside. I had to replace the heater core. I also found a lot of debris in the heater door hinge area, including a screw that was (possibly) binding the door up - but that had nothing to do with the lack of hot air, the core was clogged up beyond Prestone's abilities.

Search here, there is a good write up with pics for the core - (changing the core isnt the problem, getting the air box out and back in is)

mixer door junk is here; I apologize for the ranting, I was an unhappy monkey

http://www.naxja.org/forum/showthread.php?t=1020640
Click to expand...

I have a feeling this is whats going on with mine as well. The weather is warming up to around upper 30's mid 40's now so I have enough heat to take the chill off.. This will make a good weekend project when it warms up even more :D
 
Mine was doing the same thing and I found that the control valve the heater control wire runs to was not going all the way. I moved it the rest of the way by hand and have plenty of heat. I havent looked at it in a will but I had to pull the wire off of it so I could keep heat in it.
 
Well did the flush today, nothing bad came out actually it was pretty clean looking for the most part. Still have no heat, its not blowing though the top vents very well but it is blasting on my feet and in the back which would be fine if it was warm air verses cold air. Any ideas?
 
groovyjeepster said:
Well did the flush today, nothing bad came out actually it was pretty clean looking for the most part. Still have no heat, its not blowing though the top vents very well but it is blasting on my feet and in the back which would be fine if it was warm air verses cold air. Any ideas?
Click to expand...

if the temperature slider is moving the cable, and the cable is moving the door that allows air to bypass the core is functioning correctly, then it could still be the core is clogged

see my other post with the link in this thread for pics of my core, that was about 50-60% clogged after flushing

that assumes you have checked the vacuum controller valve, (if you still have it) like a half dozen other people have mentioned

the air not being distributed well could be the mixer door operation, the doors could be binding from debris falling in from the defroster vents (see a post titled 'mixer door operation' where I had a pic of all the crap that I dug out of the lower door hinge) or the doors could be not moving due to a vacuum leak in the controller

so to re-state the obvious, the vacuum valve under the hood allows coolant to the core, the cable actuated flapper door allows outside air to bypass the core for less than full hot, and the mixer doors get steered around by a vacuum selector

If it isn't the cable door that allows bypass air, then your core is clogged. IMHO the OEM tubing is too fine and easily clogged.

When you have the airbox out for the core change, and before you open the cooling system, you can watch the mixer doors operate with the engine running and go from there.
 
Alright thanks, well maybe I'll try flushing it again, if it doesn't work I guess I'm just going to have replace my core then. I did notice the vacuum motor under the dash isn't operating. When is this suppose to operate and whan does it exactly do. I can move it with my hand and I notice the door opens. And I do have one red vacuum hose that comes out of the fire wall thats not connected to anything but I can't find any loss ends that it goes too??
 
groovyjeepster said:
Alright thanks, well maybe I'll try flushing it again, if it doesn't work I guess I'm just going to have replace my core then. I did notice the vacuum motor under the dash isn't operating. When is this suppose to operate and whan does it exactly do. I can move it with my hand and I notice the door opens. And I do have one red vacuum hose that comes out of the fire wall thats not connected to anything but I can't find any loss ends that it goes too??
Click to expand...

PM me your email address and I will send you a file with the vacuum/door diagrams.
 
groovyjeepster said:
Good news! My heat works now, its taken awhile but its getting better but I still only have heat coming out by my feet and not out of the dash ducts.
Click to expand...

And the solution was...?
 
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