In desperate need of help with coolant problems

[Austin O.]

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.

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.

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!!

 

[Potomus Pete]

You are going to have to watch more videos and take your time. Going slow and doing everything in order. Your water pump may/probably was the problem to start with. Do it right and you will never have to do it again. As you read about the water pump removal and replace you will see how important it is to get the area clean. You can do it, and save your self at least one thousand dollars

 

[MountaineerTom]

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.
View attachment 386925

View attachment 386926

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.

View attachment 386932
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!!

The t-stat housing can be a pain. You have to make sure the t-stat stays seated in the recess in the head. If it doesn't, and slips down, it could crack the housing when you tighten it.

The water pump has hole in the bottom side that will leak coolant when the seal wears out.

Make sure the surfaces where your t-stat housing and water pump mate to are as clean/smooth as possible. A razor blade works well for scraping gunk off.

Looks like you need a thorough chemical flush. Thermocure gets great reviews on this site.

You got this.

 

[mrblaine]

Loosen the bolt on the front of the power steering pump pulley, then turn the tensioner bolt up at the top of the mount to loosen the belt so you can pull it out of the way. I strongly suspect the crack in the thermostat housing was done by you tightening the bolts with the thermostat misplaced.

 

[Austin O.]

Loosen the bolt on the front of the power steering pump pulley, then turn the tensioner bolt up at the top of the mount to loosen the belt so you can pull it out of the way. I strongly suspect the crack in the thermostat housing was done by you tightening the bolts with the thermostat misplaced.

That was my guess. Thanks

 

[Austin O.]

The t-stat housing can be a pain. You have to make sure the t-stat stays seated in the recess in the head. If it doesn't, and slips down, it could crack the housing when you tighten it.

The water pump has hole in the bottom side that will leak coolant when the seal wears out.

Make sure the surfaces where your t-stat housing and water pump mate to are as clean/smooth as possible. A razor blade works well for scraping gunk off.

Looks like you need a thorough chemical flush. Thermocure gets great reviews on this site.

You got this.

Thank you. I cleaned the housing well with a razor blade, but the thermostat kept slipping, so as you said, that’s probably that problem. Sounds like I’ll need to take a look at the water pump as well when I get back.

 

[red02tj]

I went through this at the end of the summer. I got a new Mopar housing for ~$45 Genuine Mopar Thermostat Housing 53006192 https://www.amazon.com/dp/B004VWXH9E/?tag=wranglerorg-20

Used a dab of permatex to hold the tstat in the recess of the block

Used this gasket FEL-PRO 35630 Thermostat Gasket https://www.amazon.com/dp/B000C2ACLI/?tag=wranglerorg-20

And liberal amounts of Permatex 22071 Water Pump and Thermostat RTV Silicone Gasket, 0.5 oz. https://www.amazon.com/dp/B01LRH7HTG/?tag=wranglerorg-20 which technically you shouldn’t need but you’ll find a bunch of us have had success with it.

This was after a course of Thermocure.

 

[Austin O.]

I went through this at the end of the summer. I got a new Mopar hosing for ~$45 Genuine Mopar Thermostat Housing 53006192 https://www.amazon.com/dp/B004VWXH9E/?tag=wranglerorg-20

Used a dap of permatex to hold the tstat in the recess of the block

Used this gasket FEL-PRO 35630 Thermostat Gasket https://www.amazon.com/dp/B000C2ACLI/?tag=wranglerorg-20

And liberal amounts of Permatex 22071 Water Pump and Thermostat RTV Silicone Gasket, 0.5 oz. https://www.amazon.com/dp/B01LRH7HTG/?tag=wranglerorg-20 which technically you shouldn’t need but you’ll find a bunch of us have had success with it.

This was after course of Thermocure.

Thanks so much! Links are super helpful

 

[TJ Jim]

Saw a pretty neat trick a while back on holding the thermostat in place. Loop a wire or string through the top of the thermostat the side that faces the hose. Pull the wire through the hose hole and pull it tight till you get it in place and snug the bolts down. You should have at this point two wires out the hose hole end, pull one side removing to wire and then torque bolts down as needed.

 

[Austin O.]

Saw a pretty neat trick a while back on holding the thermostat in place. Loop a wire or string through the top of the thermostat the side that faces the hose. Pull the wire through the hose hole and pull it tight till you get it in place and snug the bolts down. You should have at this point two wires out the hose hole end, pull one side removing to wire and then torque bolts down as needed.

Ingenious!

 

[Austin O.]

Quick question - when I got a new thermostat housing from AutoZone, it came with a gasket and thermostat. This small kit was said to fit a Jeep TJ. The housing fit correctly, but the thermostat that came with it was a bit smaller in diameter than the one already in the jeep.

It didn’t fit in the small recess on the block. I put back in the old one and that is what’s in there right now.

Here’s the new one - about 1 3/4” in diameter.

I’m not sure what the old one is since it’s currently in there and I didn’t have time to take it back out before leaving this morning. Should I get a new thermostat? I assume so, if so, what’s the correct one to get? Once again, thanks so much. Y’all are such a huge help

BTW - Water pump, RTC, and new gaskets are all ordered already.

 

[red02tj]

Quick question - when I got a new thermostat housing from AutoZone, it came with a gasket and thermostat. This small kit was said to fit a Jeep TJ. The housing fit correctly, but the thermostat that came with it was a bit smaller in diameter than the one already in the jeep.

It didn’t fit in the small recess on the block. I put back in the old one and that is what’s in there right now.

Here’s the new one - about 1 3/4” in diameter.
View attachment 387051
I’m not sure what the old one is since it’s currently in there and I didn’t have time to take it back out before leaving this morning. Should I get a new thermostat? I assume so, if so, what’s the correct one to get? Once again, thanks so much. Y’all are such a huge help

BTW - Water pump, RTC, and new gaskets are all ordered already.

If you’re not going Mopar, lots of us use
Superstat ® Premium Thermostat https://www.amazon.com/dp/B000C7YRNM/?tag=wranglerorg-20

And don’t forget to drill a burp hole in the new one. Also not a bad idea to put the new one in a pot of water and use a meat thermometer to make sure it opens at 195

https://wranglertjforum.com/threads/burp-hole-in-new-thermostat-location.28617/

 

[Austin O.]

Thanks!

 

[BlueC]

@Austin O. Since you're likely doing a water pump, you should consider replacing the serp belt/tensioner/pulley at the same time. I recommend Gates.

 

[JMT]

Thanks!

You’re throwing parts at it without knowing the source of the problem. I have the exact problem you described on a rig right now). Nothing wrong with flushing the coolant, but what about the radiator cap? What about pressure testing the system? Compression test to see if cracked block or head)?

If you install a new water pump go with Mopar/Chrysler. For TStat you can go with a better quality Flowmaster (330-195).

https://flowkoolerwaterpumps.com/co...0-160-degree-thermostat?variant=9125073354804

Yeah, you can remove serpentine belt by releasing the belt tensioner.

Also, those tstat housing have low torque specs. They crack commonly

 

[Austin O.]

@Austin O. Since you're likely doing a water pump, you should consider replacing the serp belt/tensioner/pulley at the same time. I recommend Gates.

Was thinking about doing the belt anyways. It’s been squealing a bunch in the cold

 

[NskLJ]

Thank you. I cleaned the housing well with a razor blade, but the thermostat kept slipping, so as you said, that’s probably that problem. Sounds like I’ll need to take a look at the water pump as well when I get back.

Very simple to do clean everything, verify the gasket fits the block and t-stat housing. Coat the block side of the gasket and the block with gasgacinch or spray glue let dry. Put stat in recess and put gasket on when you touch the two it will stick so have it lined up. The gasket will hold the thermostat in place and you will have two hands to install the housing.
https://www.amazon.com/dp/B0012TTDN8/?tag=wranglerorg-20

 

[BlueC]

You’re throwing parts at it without knowing the source of the problem. I have the exact problem you described on a rig right now). Nothing wrong with flushing the coolant, but what about the radiator cap? What about pressure testing the system? Compression test to see if cracked block or head)?

@Austin O. ^ this is good advice, if you can get everything put back together with reasonable time/expense. If you can get it back together, start off with pressure testing the cooling system. Rent a tool kit from one of the local parts stores. If you can't find a problem there, then considered other test like compression and leak-down. Just take it one step at a time using logic and reason.

Was thinking about doing the belt anyways. It’s been squealing a bunch in the cold

If you wind up doing the water pump, it makes sense to do that job as well, and buy a complete component kit with belt, tensioner and idler. Rockauto currently has a Gates kit ('03 4.0 w ac) for $62.89 https://www.rockauto.com/en/moreinf...TS7idFPCyUxElmPri9tDmHijRqCM4N/VuNqNdp3W+S6zZ

 

[Austin O.]

@Austin O. ^ this is good advice, if you can get everything put back together with reasonable time/expense. If you can get it back together, start off with pressure testing the cooling system. Rent a tool kit from one of the local parts stores. If you can't find a problem there, then considered other test like compression and leak-down. Just take it one step at a time using logic and reason.



If you wind up doing the water pump, it makes sense to do that job as well, and buy a complete component kit with belt, tensioner and idler. Rockauto currently has a Gates kit ('03 4.0 w ac) for $62.89 [URL]https://www.rockauto.com/en/mo...TS7idFPCyUxElmPri9tDmHijRqCM4N/VuNqNdp3W+S6zZ[/URL]

I’ll do that. Thank you

 

[Austin O.]

Working on it now, have a slight problem. The idler pulley won’t loosen enough for me to take the belt off. The belt is still very tight with the pulley loosened all the way. What do I do?