In desperate need of help with coolant problems

Austin O. said:
Right when I thought I was done with all the big maintenance stuff in my jeep…

A couple days ago, the temperature dropped down to around 0*F that night and for the first time I had problems with the heater. It had always worked previously, but now it was blowing cold air.

I knew that was a sign of possibly bad coolant, and I had never checked coolant on the tj since buying it. Sure enough, the coolant in the radiator was dark brown and had some particles in it.

I went to AutoZone to buy new coolant, planning to flush the whole system, and on the way home, I was almost home when the tj overheated on the highway just before my exit. Steam coming from under the hood. I pulled over, waited for it to cool down all the way for about 25 minutes, got into my neighborhood, it overheated again. From there, my Dad just came and towed me home with his jk.

I took apart all the pipes in the cooling system, flushed everything with the help of 3 YouTube videos. It was quite disgusting what came out of there.
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After flushing it all, everything had gone really well, and I started putting it all back together. Got everything together except the thermostat housing. That thing is the biggest PITA to get back in since the serpentine belt is right there in the way of the lower bolt. I get it in, start putting coolant in, and it all starts leaking out of the thermostat housing… I think

I take the housing out, and it’s got a huge crack in it.

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Back to AutoZone I go, get a new housing, and don’t have time to put it in yesterday.

After Christmas this morning, I go back out and put it in. Once again, huge PITA. I put the coolant in, and it is streaming out of somewhere. I assume it’s the thermostat housing, so I tighten it down as tight as I can. There is still a drip coming from there, but coolant seems to be streaming out of the oil pan gasket??

After some research, it seems that it could actually be leaking from the water pump and running down to there? Is that right? Do I need to replace water pump now?

Anyways, I’m feeling super defeated, not at all happy with this, but I am learning a lot. Is it worth me trying to fix it myself, or should I bring it in to a shop? I just don’t want to screw anything up any more than I have already. Id love to do it myself, but right now, I don’t know that’s a good idea.

If I do attempt to do it myself, Is there an easy way to get the serpentine belt off and back on so I can make sure the thermostat housing is on there correctly? Is the water pump what I need to replace? Am I missing something else?

I’m leaving tomorrow morning to go on vacation and will get back in a week. I’ve got some time to watch some videos and do some research. Obviously, I’d love to drive the tj soon after I get back, but if doing the work on it will take a couple days, I have my moms old car to drive. I mainly do not want to have to pay a shop to replace everything, however that might be best at this point.

I’m sorry that was so long, just kinda gotta rant about it 🤣 Thanks in advance to anyone can help!!
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Austin O

Happy new year to ya.

There’s already great input from our “Jeep-family”. Here’s my two bits :
•Vacuum fill the coolant in the Jeeps cooling/heating system.
• not everyone has access to a vacuum fill set up, but I’m certain you’ll find a way 😉.
•as for the brown stuff in your engines cooling system makes me think that someone in the past ran straight water (rust) instead of coolant

🚧DETOUR👋🏿🚧

•Going the xtra mile - it’s never crowded•
 
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DETOUR said:
Austin O

Happy new year to ya.

There’s already great input from our “Jeep-family”. Here’s my two bits :
•Vacuum fill the coolant in the Jeeps cooling/heating system.
• not everyone has access to a vacuum fill set up, but I’m certain you’ll find a way 😉.
•as for the brown stuff in your engines cooling system makes me think that someone in the past ran straight water (rust) instead of coolant

🚧DETOUR👋🏿🚧

•Going the xtra mile - it’s never crowded•
Click to expand...

Happy new year

Straight water would definitely explain why I think it froze, along with the rust. That was my guess as well. Thanks for the help!
 
DETOUR said:
Austin O

Happy new year to ya.

There’s already great input from our “Jeep-family”. Here’s my two bits :
•Vacuum fill the coolant in the Jeeps cooling/heating system.
• not everyone has access to a vacuum fill set up, but I’m certain you’ll find a way 😉.
•as for the brown stuff in your engines cooling system makes me think that someone in the past ran straight water (rust) instead of coolant

🚧DETOUR👋🏿🚧

•Going the xtra mile - it’s never crowded•
Click to expand...

No need to vacuum fill the earlier ones. 1/8" hole in the thermostat flange installed with that at the highest point, basic fill with coolant funnel will get all the air out easily.
 
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Just got everything apart, picked up the new parts, and having lunch. Thanks for all y’all’s help so far. Hopefully the rest goes smoothly
 
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I’ve got the gasket sealer stuff. What side of the paper gasket do I put it on for both the water pump and the thermostat housing? And how much?
 
You don't need to add a sealant or RTV to paper gaskets in the cooling system, The factory doesn't even use anything but paper gaskets there. They do use RTV elsewhere but not on the cooling system.

My engine overheated on the trail years ago from the thermostat getting stuck in the closed position. I removed the thermostat and cut a new gasket out of a handy cardboard box which was leak free for months until my OCD got the best of me and I replaced it with a "real" gasket. I suspect the gasket I cut out of the cardboard box would have been fine forever though.
 
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Jerry Bransford said:
You don't need to add a sealant or RTV to paper gaskets in the cooling system.
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Assuming you can get a good mating surface. Took me four laps to get a leak free sealing...I replaced my housing, sanded the block with 240 grit paper on a block. Lots and lots of cleaning and scraping and filing and sanding and checking things with straight edges.

In the end I gooped up the RTV good... loosely put on the housing...bolts barely finger tight...let it sit 24 hours to cure and then did a final torque.

Your mileage might vary. Start with a gasket and the factory way but don't get bummed out if you have to punt.

-Mac
 
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mrblaine said:
That might be more successful if you have a thermostat housing that has the recess in the housing and not the block. In this case, that would drive you crazy moving the housing around to seat the thermostat in the recess and getting the gasket in place over it.

Easy way is to put a thin layer of RTV on the edge of the thermostat, stick it in the recess, then the gasket, then the housing.
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Haven’t had mine apart yet so I was wondering if the recess was in the block or the housing. Now I know. Thanks. Adding the rtv would be my second choice of getting it done.
 
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