Gen 2.5 Heater Core Replacement - Tips, threads, pictures, etc

TNMontero

Old Monty fan
Hoping I pick up a Gen 2.5 this next week. Has a bad heater core in, good thing it had heated seats for the guy as he's in a cold part of the country.

I know it's a full dash removal, but any tips or threads on it would be helpful. I did a search and it pulled up tons of people talking about it, but nothing more. I plan to try and flush it first to make sure it's not just caked dirty. But I have a feeling I'm not that lucky. I did this once on a Grand Cherokee, and it sucked.
 

airbox

Member
Hi TNMontero, Just finished mine. It wasn't too bad. It would be a good idea to try and flush it, but if it is leaking then it is most definitely cracked. The radiator shop said it was cracked on the lower tank and all rods were full of crap. I baggied and labelled all the bolts from each separate dash component, i.e. the glove box bolts, radio bolts, voltmeter/compass gauge screws, etc... Had to unbolt and lower the steering wheel column as well. The youtube video helped to a point then I had to consult the FSM to figure out what else to remove. The HVAC box unit was almost impossible to remove from the inner dash "cage" so I just pulled the heater core from the top. Took me about 2.5 to 3 hrs to remove the dash and that was me being meticulous and thorough.
 

dos531

Member
FWIW my heat was non functional when I bought my gen 2, but after reverse flushing the heater core it started working. I've been fighting cooling system rust and also just did a thermocure flush and its working even better now. I was not looking forward to changing it out if the flush didnt work.
 

Salonika

Monterror Pilot
The FSM has the complete procedure. With any job that big I like to setup a few tables and as I take things apart, I set them on one end of the table and work to the other end. It’s a lot easier to put stuff back together when all your parts are laid out in the order you removed them.
 

TNMontero

Old Monty fan
Hi TNMontero, Just finished mine. It wasn't too bad. It would be a good idea to try and flush it, but if it is leaking then it is most definitely cracked. The radiator shop said it was cracked on the lower tank and all rods were full of crap. I baggied and labelled all the bolts from each separate dash component, i.e. the glove box bolts, radio bolts, voltmeter/compass gauge screws, etc... Had to unbolt and lower the steering wheel column as well. The youtube video helped to a point then I had to consult the FSM to figure out what else to remove. The HVAC box unit was almost impossible to remove from the inner dash "cage" so I just pulled the heater core from the top. Took me about 2.5 to 3 hrs to remove the dash and that was me being meticulous and thorough.

Airbox, you mentioned in your message you had a hard time sourcing a heater core. I thought I saw someone had gotten a new one (been searching threads so much I can't remember). Where are people getting their heater cores?
 

airbox

Member
Airbox, you mentioned in your message you had a hard time sourcing a heater core. I thought I saw someone had gotten a new one (been searching threads so much I can't remember). Where are people getting their heater cores?
I saw that too, but once I started using the links provided by other members, there weren't any. I tried ordering one from parts.com but they were completely out, even though they said it was in stock on the site. They cancelled my order after a day or two, so I was at square one. I sourced maybe one or two by phone but they wanted about $400-600 for them for them. Buddy of mine and my dad convinced me to try and have the original recored and patched. Figured I'd try my chances as it was much cheaper and worst case scenario I got to do it all over again.
 

Toasty

Looking for that thing i just had in my hand...
think about replacing the HVAC controler while you're in there because it's easier to do with the dash apart and not a real expensive part. I also replaced my combination switch, antisqueek taped and noico'd under the dash while i was in there.
 

TNMontero

Old Monty fan
think about replacing the HVAC controler while you're in there because it's easier to do with the dash apart and not a real expensive part. I also replaced my combination switch, antisqueek taped and noico'd under the dash while i was in there.

Yeah, I've read about that as well. Thanks. Where did you put the anti squeak and noico? Everywhere? LOL

Big, complicated, time consuming job = spend the money on an OEM part. Do the next owner of your truck a favor.

Do they still sell OEM heater cores for this Gen? (Nevermind, found them on the OEM Mitsubishi parts page, dang them 'spensive!)
 
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SONICMASD

Adventurer
think about replacing the HVAC controler while you're in there because it's easier to do with the dash apart and not a real expensive part. I also replaced my combination switch, antisqueek taped and noico'd under the dash while i was in there.

I remember being over at Toasty's garage when he was midway through this process and I gotta say - this is a job you only want to do once. Yikes.
 

evomaki

Observer
After reading about how difficult it is to find a heater core for my gen 2.5, I found out for myself. Could not find one for sale in the US, aftermarket or from the usual Mitsubishi sources. Ebay may have had one for crazy $. I stumbled onto a parts distributor out of the UAE, Carmarka, and rolled the dice. It took some time but after a couple of months, this showed up. The packaging was impressive, like something you'd ship space station parts in. The part number should be right (MN188337). Never having replaced one of these on a Montero (I bought this as a spare since these are supposed to be a known problem), I can't say anything definitively other than this looks like a heater core. This look right to any of you all who've done the job? Wonder why this included a new case? Also, you all know the part number for the HVAC controller Toasty was talking about? Sounds like something to do while in there. If this proves to be the right part, I'd then have to say Carmarka was definitely OK, and I'd give them a try again for something NLA otherwise.

IMG_0335.jpg

IMG_0336.jpg
 

johnsky

New member
I saw that too, but once I started using the links provided by other members, there weren't any. I tried ordering one from parts.com but they were completely out, even though they said it was in stock on the site. They cancelled my order after a day or two, so I was at square one. I sourced maybe one or two by phone but they wanted about $400-600 for them for them. Buddy of mine and my dad convinced me to try and have the original recored and patched. Figured I'd try my chances as it was much cheaper and worst case scenario I got to do it all over again.
I just replaced the heater core on my 95 SR. Using an online reference table, I was able to find a number of cores with the very similar dimensions. Further investigation revealed a couple cores that had an inlet/outlet pipe configuration that was compatible. I ended up getting this one for an older Ford medium duty truck. https://truckerac.com/heater-core-ford--sterling-c-series-oem-e6hz618476.html I had to trim the plastic around the top of the slot the core drops into, and stick a few layers of padding in various spots to make it secure. Also had to cut the pipes a bit shorter to fit sections of hose in. I used a couple molded 5/8 universal heater hoses and cut them to length. I believe this core could also be made to work. https://www.amazon.com/APDI-9010166-HVAC-Heater-Core/dp/B00GVHZVMI

1594745676376.png
 

johnsky

New member
I just replaced the heater core on my 95 SR. Using an online reference table, I was able to find a number of cores with the very similar dimensions. Further investigation revealed a couple cores that had an inlet/outlet pipe configuration that was compatible. I ended up getting this one for an older Ford medium duty truck. https://truckerac.com/heater-core-ford--sterling-c-series-oem-e6hz618476.html I had to trim the plastic around the top of the slot the core drops into, and stick a few layers of padding in various spots to make it secure. Also had to cut the pipes a bit shorter to fit sections of hose in. I used a couple molded 5/8 universal heater hoses and cut them to length. I believe this core could also be made to work. https://www.amazon.com/APDI-9010166-HVAC-Heater-Core/dp/B00GVHZVMI

View attachment 598411
Also ended up having to point the protruding portions of the clamps closest to the firewall down. They were preventing the heater assembly from going fully into place. The clearance between the assembly and the firewall is minimal.
 

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