Jeep Wrangler TJ Cooling System Overhaul FAQ

Super helpful post. Thank you! Very useful thread for getting this project planned out. Not sure what happened with the OEM radiators, but they are over $300 now!

You're very welcome!

Yes, the OEM radiators were once a lot cheaper, but as Mopar stopped producing them, they've gone up in price significantly. At some point soon you'll never be able to get an OEM radiator again unfortunately.
 
  • Like
Reactions: Dmn0805
You're very welcome!

Yes, the OEM radiators were once a lot cheaper, but as Mopar stopped producing them, they've gone up in price significantly. At some point soon you'll never be able to get an OEM radiator again unfortunately.
I am still collecting parts. I noticed the water tube that connects from the water pump to the heater hose is badly rusting/bubbling. Is the Dorman version safe to use or do I need the Mopar? I also realized the only remaining stock item in the mix is the temp sensor on the t-stat housing - might as well thread a new one into the new housing, but is there a recommended brand? A Stant is $3 and the Mopar is $40, with no less than ten choices in between!

Thanks
 
I am still collecting parts. I noticed the water tube that connects from the water pump to the heater hose is badly rusting/bubbling. Is the Dorman version safe to use or do I need the Mopar? I also realized the only remaining stock item in the mix is the temp sensor on the t-stat housing - might as well thread a new one into the new housing, but is there a recommended brand? A Stant is $3 and the Mopar is $40, with no less than ten choices in between!

Thanks

Dorman is fine for the tube. For the sensor I would use Mopar.
 
@Mfpaul73 , these Wranglers seem to be so finicky when it comes to sensors, so I went with the MOPAR one even though it was quite a bit more costly.

On the tube, I used a Dorman and it works fine. I did read on this site, I think, that someone had problems threading it in the pump after adding thread sealant. They suggested removing the paint that is on the threads. I did just that and used Permatex high temp thread sealant on the tube and the sensor and everything worked smoothly and no leaks. Don't put the sealant all the way down to the ends of the threads on the pipe of sensor that way you don't get it in the cooling system.
IMG_8982.JPG



As an alternative to the tube, I thought about doing something like this and just getting a longer heater hose, or splicing in one that is shaped like the tube. If you ever need to replace that tube, the pump has to come off because other things are in the way when trying to remove or install in on the engine. I decided not to because the hadn't rusted through or anything and I don't live in a road salt area, It is an alternative though.
003.jpg
 
  • Like
Reactions: Dmn0805 and Haanz
@Mfpaul73 , these Wranglers seem to be so finicky when it comes to sensors, so I went with the MOPAR one even though it was quite a bit more costly.

On the tube, I used a Dorman and it works fine. I did read on this site, I think, that someone had problems threading it in the pump after adding thread sealant. They suggested removing the paint that is on the threads. I did just that and used Permatex high temp thread sealant on the tube and the sensor and everything worked smoothly and no leaks. Don't put the sealant all the way down to the ends of the threads on the pipe of sensor that way you don't get it in the cooling system.
View attachment 147952


As an alternative to the tube, I thought about doing something like this and just getting a longer heater hose, or splicing in one that is shaped like the tube. If you ever need to replace that tube, the pump has to come off because other things are in the way when trying to remove or install in on the engine. I decided not to because the hadn't rusted through or anything and I don't live in a road salt area, It is an alternative though.
View attachment 147954
Super helpful. Thank you!
 
  • Like
Reactions: MountaineerTom
@Chris, I’d just like to confirm before purchase. You list in the original post that the correct radiator for the 1997 4.0 is 55037652AA. On Amazon, it says that one does not fit the 1997, but 00-06. On Rockauto, it is listing 5102983AA as the correct radiator for the 1997. Will the 5503 work? Rockauto has it for $180, where the 5102 is $438! I’d like to go with the Mopar rad, but can’t afford it at over $400!
 
@Chris, I’d just like to confirm before purchase. You list in the original post that the correct radiator for the 1997 4.0 is 55037652AA. On Amazon, it says that one does not fit the 1997, but 00-06. On Rockauto, it is listing 5102983AA as the correct radiator for the 1997. Will the 5503 work? Rockauto has it for $180, where the 5102 is $438! I’d like to go with the Mopar rad, but can’t afford it at over $400!

Interesting. At one point that part number showed it fir 97s. However, the 97-00 looks like it's been removed from most online parts catalogs entirely.

That being said, go with the one on RockAuto, since it will for sure work.
 
  • Like
Reactions: Dmn0805
One quick question after finishing today:

I refilled first with one gallon of the 5 year MOPAR embittered/concentrate coolant and then one gallon of distilled water, all through the radiator, one at a time while the engine ran and it heated up. Then I emptied about 1/5-1/4 of a leftover gallon of distilled into the reservoir after burping it and then drove it around. A LOT burped before I put the cap back on. Was that enough coolant and water?

When the leak started, I initially topped off with distilled when I ran it by the shop, then the shop generously topped it off with coolant after confirming the leak for me. I assume there was some still left in the block and heater core so I also assumed the 2 gallon 50/50 was enough.
 
I need to overhaul my cooling system--radiator is leaking. I looked up parts based on this thread (2000 TJ I-6, manual trans) and the P/N for the radiator in the heading is showing as not compatible in the Amazon link and the mopar sites I'm checking.

Anyone have access to a service manual or parts catalog with the correct radiator P/N? Or, is this a matter of sites updating catalogs to remove 'classics' like my rig?

Here's a screen shot of what's giving me pause from ordering:
radiatorfitment.jpg


Not showing up at RockAuto either.
My rig: https://www.rockauto.com/en/catalog/jeep,2000,wrangler,4.0l+l6,1363441,cooling+system,radiator,2172
Part: https://www.rockauto.com/en/parts/mopar,55037652AA,radiator,2172
Listing for different year models, I guess.
 
Amazon is known to tell you stuff isn't compatible when it actually works just fine. Someone else can confirm but a quick glance at the comments shows other folks used it for similar model years.
 
Thanks so much guys! The parts book has helped reassure me and I found a slightly less confusing mopar catalog to check P/N supersessions
I have a brand new Mopar water pump for my 98 I didn’t need if you want to save some money PM me.
 
  • Like
Reactions: Chris
@Chris, I just want to confirm that Mopar 55037652AA does fit properly in a 1997 4.0 with a manual transmission.

Yes, I pulled that info from the part diagrams directly. However, it appears that since you can no longer even lookup parts for a 1997 online (see https://wermopar.com for what I am talking about), they have changed it so it now says it fits 2001 and up models.

But yes, it does indeed fit your 1997 4.0 with a manual.
 
So it's OK to do this cooling system overhaul without replacing the radiator, water pump, and fan clutch? Or should I really do these as preventative measures?
208k on the odometer and I don't know if this has ever been done. No overheating/cooling issues that are visible.