HVAC temps in a good working TJ with a good HVAC system

Nopp said:
In need a new heater core as well... @JMT I know you do a ton of research on stuff - what did you determine was the best available heater core to get?

Do you have a rock auto link? thanks!
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Mopar!

But since they’re unavailable I went with this one.

https://www.rockauto.com/en/parts/agility,9010450,heater+core,6864

I don’t know how it’s going to perform. I ended up buying it because another forum member was getting good heat at the vents and that seems rare for aftermarket heater cores.
 
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Nopp said:
In need a new heater core as well... @JMT I know you do a ton of research on stuff - what did you determine was the best available heater core to get?

Do you have a rock auto link? thanks!
Click to expand...
I would have given you a Rockauto link but I can't figure out what model year you have other than it has to be an 03 to 06, your Profile has zero information about your Jeep. Provide your model year (and please complete your Profile) and I'll be happy to provide a Rockauto link for your TJ. :)
 
I went with the Amix core, needed to have heat…. With just an idle in the driveway at 37 degrees, I was able to hit 135. Was going up with a few RPM.

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Here’s what the Omix replaced yesterday. I do not remember the brand, only that my wife ordered it from Quadratec. I was out to do the brake brake in procedure, accelerating, and heard a loud pop; thought I hit something, then started smelling coolant. The tubes just blew out of the tank plate, the only thing that kept it together was the hvac box…

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Artsifrtsi said:
Here’s what the Omix replaced yesterday. I do not remember the brand, only that my wife ordered it from Quadratec. I was out to do the brake brake in procedure, accelerating, and heard a loud pop; thought I hit something, then started smelling coolant. The tubes just blew out of the tank plate, the only thing that kept it together was the hvac box…

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Holy cow. Did it make a mess?
 
NashvilleTJ said:
Holy cow. Did it make a mess?
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Luckily, the coolant was able to make it out the drain through the firewall.

In doing the replacement, the dash defroster panel went from I’ll get to it, to gone; and the dash panel under the steering wheel decided to show how brittle it had become…


On a positive, it only took 5 1/2 hours by myself to r&r….
 
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mrblaine said:
JMT said he was going to swap in a heater core that was touted to deliver 150 degree air. I said I had no idea where that put things but I'd find out, so I ordered in a Robinair instant read HVAC thermometer to find out. These are the temps from one with known good Mopar stuff in it.
Ambient with the sun heating up the black dash bits. No AC or defrost running.
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Very close to actual ambient.

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I started it up and while waiting for the engine to get up to temp and open the thermostat, I turned on the AC just to see what it was doing.

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It got up to temp, opened the thermostat and the heater started working. Center vents first.
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And then the fun one. I was trying to hold the thermometer in the floor vent but it kept roasting my fingers. I had to go get a clamp to do it. When I saw the temp, I understood. Scalding is 150. 164 is toasty.

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Oddly, the defrost is a bit less but I suspect that would go up as the ductwork warmed up, this was all cold when I started. I didn't leave it there long since the heat was driving me out of the rig even with the windows down. If it matters, I can do it again to see what happens when I don't mess with the AC first, but the floor vents tell the story.
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@P man

Granted my evidence is anecdotal, but don't get the AGILITY heater core I got through Rock Auto. It's not even worth checking the temps. It's obviously not even as warm as body temperature. Piece of crap now inside my HEVAC. I'll have to go back in before next winter or move to southern California.

EDIT: it helps if you plug in all the plugs. Now I’m getting hot air. Plenty hot.
 
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JKP said:
It would be hard to stomach the price, but these guys seem to have done the homework and come up with something that might equal the OEM.

https://www.thebrassworks.net/collections/heater-cores/products/2002-2006-jeep-wrangler-heater-core
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I read their description, then I emailed them to get some real data. I don't care how many fins they have. I want to know what the air temp coming out of the various vents is and the ambient temp they tested their heater core with in a TJ.
 
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JKP said:
It would be hard to stomach the price, but these guys seem to have done the homework and come up with something that might equal the OEM.

https://www.thebrassworks.net/collections/heater-cores/products/2002-2006-jeep-wrangler-heater-core
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That's an interesting new narrative on their web page. In the second paragraph, they say that they listened to Jeep owners' feedback on forums (presumably this was one of them). In the third paragraph, they take a passive-aggressive stance when they say, "Some listen to us and some hang out on forums."

Brassworks, if you're reading this, just make a heater core that works, and you'll have a bunch of sales to the members of this forum! Some of the folks that hang out here are pretty smart, but even the dumb ones, like me, can tell when a heater core doesn't work. 🤣
 
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I put an OSC heater core from RockAuto in back in December, I can say the heat output is definitely not as good as my leaking Mopar but if it helps any I’ll order a Robinair thermostat from Amazon and I can post up some heat readings, even just for comparison.
OSC heater core.JPEG
 
James9100 said:
I put an OSC heater core from RockAuto in back in December, I can say the heat output is definitely not as good as my leaking Mopar but if it helps any I’ll order a Robinair thermostat from Amazon and I can post up some heat readings, even just for comparison.
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Bummer. OSC is what I have in my parts pile waiting for when it's needed. Good thing they're inexpensive.

When it comes to physical characteristics that are directly tied to performance, the OSC gave me the most optimism out of 3 that I examined.

The specs on the brassworks unit above look like they should perform well...if not perfectly matching OEM, I see no reason it shouldn't beat the inexpensive rockauto options.

While I do like the OE heater performance and would prefer to keep it, I think I'd be ok with losing a couple of degrees if I knew I was getting something that would last as long as the first one did.
 
sab said:
That's an interesting new narrative on their web page. In the second paragraph, they say that they listened to Jeep owners' feedback on forums (presumably this was one of them). In the third paragraph, they take a passive-aggressive stance when they say, "Some listen to us and some hang out on forums."

Brassworks, if you're reading this, just make a heater core that works, and you'll have a bunch of sales to the members of this forum! Some of the folks that hang out here are pretty smart, but even the dumb ones, like me, can tell when a heater core doesn't work. 🤣
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My questions would be slightly different.
1- Do you know what the heat output should be in order to land within or exceed the Mopar specifications?
2- How close do you get to that and when I send you pics of my thermometer showing it to be lower than OEM, how do you plan to fix that?

The only thing I can think of that would cause them to say folks don't listen is when the heat output is too low and they tell the owner it isn't.
 
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freedom_in_4low said:
The specs on the brassworks unit above look like they should perform well...if not perfectly matching OEM, I see no reason it shouldn't beat the inexpensive rockauto options.

While I do like the OE heater performance and would prefer to keep it, I think I'd be ok with losing a couple of degrees if I knew I was getting something that would last as long as the first one did.
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I’m hoping my OSC will last a decent while. It’d be nice to have something better for our prairie winters but I’d be looking at nearly $650 CAD to get a Brassworks. That’s a lot for a heater core even if it is a good product. I don’t drive my TJ on the daily anyways so as long as it lasts I’ll deal with it.
 
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mrblaine said:
My questions would be slightly different.
1- Do you know what the heat output should be in order to land within or exceed the Mopar specifications?
2- How close do you get to that and when I send you pics of my thermometer showing it to be lower than OEM, how do you plan to fix that?

The only thing I can think of that would cause them to say folks don't listen is when the heat output is too low and they tell the owner it isn't.
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The point of my post was that this forum can tell when a heater core works and when it doesn’t, in spite of what they say on their web site. They’ve bragged about how great their cores are, yet they’re also about to introduce a third version. According to them, the first version was awesome, so I wouldn’t trust them to answer any question truthfully…
 
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RE: Brassworks, a possibility I'm willing to entertain is that their tube shape presents less of a blockage to airflow, and would therefore balance with the fan at a higher flow and velocity through the heat exchanger.

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This can easily result in more BTU/h heat transferred but with less temperature rise since the energy is being transferred into more mass of air. Said another way, it could easily be that it keeps your cab just as warm and warms it up just as fast despite having less of that foot blistering sensation we're used to.

If their FPI is 20 and OEM is 21, that's close enough for me, and the fact that they're copper is good because it transfers heat at almost double that of aluminum.

HOWEVER...that tube shape means it's unlikely they are mechanically expanded into the fin, and the image certainly looks like they are brazed or soldered and that's less ideal. It's also a little concerning that their tube thickness is only .007 according to the table...that would be a very common fin thickness, and it folds like paper at that point. Makes me think the table was put together by a writer or a web dev that doesn't know fin from tube, or they're counting on that braze filler material to structurally bolster the tube.
 
Just noticed “the smell” this morning when I turned on the heater in my 06 LJR.
So Agility is a no go and OSC may be a little cooler than stock?
Looking for any advice on heater core and evap as I really don’t want to do this twice.
Spending most of my weekends just working on the Jeep replacing stuff.

My dad was right when he told me back when I purchased my first vehicle…
“son if it’s got tits or tires it’s gonna take all your money and patience”
 
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mrblaine said:
No one has yet reported that the top version works as good as OEM. The ones below that do not which has been reported.
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I was speaking with a local jeeper a few months back. He has the Brassworks heater core in his 2003 TJ. He said it was no better than the Advanced Auto parts one he removed. His reason for removing Advance unit was the typical it doesn't blow as hot as the factory heater core. He also said he waited almost 2 months for the Brassworks piece.
My stock heater core blows close to 180 out the center vents. Unfortunately, it leaks and needs to be replaced.
I have a new heater and evaporator core to install. I just keep putting it off because I know they are not going to perform as well.
On a side note, the aftermarket blower motors do not move as much air as the mopar unit.
 
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