How to replace the heater core on a Jeep Wrangler TJ

yelloTJ said:
In the process of working on mine...... Has anyone researched to see what compatibility is? 1997 to 2006 / auto VS Manual / 2.5 VS 4.0L / AC VS no AC?

I only use my heater really to defog and the odd time for heat in early spring / late fall. I am looking to spend little as possible and am sourcing options for a used replacement.... Either that or go aftermarket.

Great Write up BTW!!!!
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the heater core for a 2.5 is diffrent than the 4.0. Auto or manual doesnt make a diffrence. If you want the cheaper route then order off rockauto. I paid 27 bucks for mine and so far ot has held up pretty good.
 
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Interesting read, reminds me of the first Cherokee heater core I changed out...I didn't pull the whole dash out, left the steering column in place and rotated and lifted the dash with bungee cords enough to access the heater/ac plenum box out from under the dash. Once it was out on the bench, opened it up, changed out the heater core and back in under the dash. Still took pretty much the whole day though, would have been more to finish removing all the disconnects to remove the steering column. Chrysler built the Cherokees and the TJs in very similar ways.

Don
 
Did mine today. No need to remove steering wheel, used cam lock tie down straps to hold the dash up out of the way. The biggest struggle was that as I was pulling the HVAC box out I discovered that the fancy full console in my 2006 LJ has to come out to let the air box assembly drop out.

Replaced with a Brassworks heater core, hopefully i never have to think about it again.
 
So I replaced my heater core in my TJ about 6-9 months ago. It lasted all of a week before the "new" heater core blew up. I didn't go back and replace it immediately because I have to remove the cage from the jeep in order to get the dash off and I didn't want to deal with it. Well....I finally bit the bullet and did the job today. Managed to get the whole thing done in 4-5 hours, which is not too bad. While I had it apart, I took the opportunity to clean up some wiring under the dash. All together now and hope this time, it lasts more than a week. Assuming it does, I'll charge the A/C and call it good.

Here is the heater core that I pulled out of the box. I'm assuming that it was fractured before I installed it. Anyone think that it might be something else? Maybe something with my system?

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My temps never exceed 210 so I doubt it got too hot. Regardless, I'm going to flush the radiator this time and get some new coolant in the system to make sure. I am NOT swapping out that heater core again.
 
Rock Toy said:
So I replaced my heater core in my TJ about 6-9 months ago. It lasted all of a week before the "new" heater core blew up. I didn't go back and replace it immediately because I have to remove the cage from the jeep in order to get the dash off and I didn't want to deal with it. Well....I finally bit the bullet and did the job today. Managed to get the whole thing done in 4-5 hours, which is not too bad. While I had it apart, I took the opportunity to clean up some wiring under the dash. All together now and hope this time, it lasts more than a week. Assuming it does, I'll charge the A/C and call it good.

Here is the heater core that I pulled out of the box. I'm assuming that it was fractured before I installed it. Anyone think that it might be something else? Maybe something with my system?

View attachment 220781View attachment 220782View attachment 220783
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Is that your new one? If so, I'd be trying to get my money back. What brand is it?
 
No idea what brand it was. Probably Amazon or O'Reilley's special. Less than $50. I don't care about the money....it was the effort of swapping it that really got me.
 
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Rock Toy said:
No idea what brand it was. Probably Amazon or O'Reilley's special. Less than $50. I don't care about the money....it was the effort of swapping it that really got me.
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I ponied up for the Mopar ($$$) when I did mine for the same reason. I haven't had to do it again, although it's only been a couple of years.
 
Hey so I replaced the heater core and now the heat isn't working. Why would it not be blowing hot anymore? The coolant level is fine and the hoses for the heater core are getting hot. Any thoughts on what could be wrong?

Could it be I did not put the door back together correctly? Maybe needs to be flushed? Hopefully something I can fix without tearing it apart again.
 
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RMETeeJay said:
I ponied up for the Mopar ($$$) when I did mine for the same reason. I haven't had to do it again, although it's only been a couple of years.
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Well, I got it all together this weekend and everything works. Praying that this one holds together for a few years. Sure is nice cruising around with the heater pumping AND the heated seats :) Livin' the dream.
 
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Finished mine this week. Spot on instructions- thanks for the writeup. My blower motor stopped working after everything was done. Is that a common occurrence? Might have bumped it or pinched a wire when everything went back in. Ended up replacing the motor and the resistor. All working and good to go now.
 
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TJTexas said:
Finished mine this week. Spot on instructions- thanks for the writeup. My blower motor stopped working after everything was done. Is that a common occurrence? Might have bumped it or pinched a wire when everything went back in. Ended up replacing the motor and the resistor. All working and good to go now.
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Finished mine yesterday as well, but with one problem - that hidden nut location behind the engine where the cowl drain attaches. How did you get the nuts back on? My hand barely fits down there, but I was able to spin it off with a finger and then grab it with the magnetic stick. But to get the nut back on requires more dexterity than I have room for. Have any tips?
 
TboneJeeper said:
Finished mine yesterday as well, but with one problem - that hidden nut location behind the engine where the cowl drain attaches. How did you get the nuts back on? My hand barely fits down there, but I was able to spin it off with a finger and then grab it with the magnetic stick. But to get the nut back on requires more dexterity than I have room for. Have any tips?
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I used a bungee cord to hold the harness out of the way, a telescoping magnet to help get the nut started and a ratcheting wrench to tighten. I have so pics that may help in this thread.

https://wranglertjforum.com/threads/another-heater-core-replacement-and-a-c-evap-core.15568/
 
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TboneJeeper said:
Finished mine yesterday as well, but with one problem - that hidden nut location behind the engine where the cowl drain attaches. How did you get the nuts back on? My hand barely fits down there, but I was able to spin it off with a finger and then grab it with the magnetic stick. But to get the nut back on requires more dexterity than I have room for. Have any tips?
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Yeah that one was tricky. Had to hand wrench it, using the 12 point box end of the 7/16 combination wrench. Just lots of small turns and patience.

For me, even with the wobbly/universal attachment, couldn't get a socket in there.
 
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