Jeep Wrangler TJ Cooling System Overhaul FAQ

Chris,
I purchased from Mopar Parts Giant. (3) upper radiator hose both ends and lower radiator hose radiator end 55037990AA, (1) lower hose end @ Water Pump 55037660AA

Rich

Thanks for sharing this information, it's much appreciated!
 
I didn’t see it listed in the original post but for those that have done this, which parts/brands are recommended to replace the serpentine belt, the temperature sensor, and the water inlet pipe? I was just going to order “amazon best seller” for each of those based on reviews but I figured I’d ask here first.
 
I didn’t see it listed in the original post but for those that have done this, which parts/brands are recommended to replace the serpentine belt, the temperature sensor, and the water inlet pipe? I was just going to order “amazon best seller” for each of those based on reviews but I figured I’d ask here first.

I just used a Gates brand for the serpentine belt and a generic brand for the inlet pipe, so yes, the "Amazon best seller" will work just fine.
 
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@Chris you recommend changing the entire cooling system at around 100k miles or >15 years old even if no issues at the moment?

I would, yes. At 100k miles it's probably still good, but with 15 years of age, that age mixed with those miles usually means it's coming due (it it isn't due already).

I'd at least purchase the parts and have them around for when something does fail. Cooling systems are usually a high point of failure for most older vehicles, especially as the warmer months come upon us.
 
I would, yes. At 100k miles it's probably still good, but with 15 years of age, that age mixed with those miles usually means it's coming due (it it isn't due already).

I'd at least purchase the parts and have them around for when something does fail. Cooling systems are usually a high point of failure for most older vehicles, especially as the warmer months come upon us.
Ok good idea. I believe previous owner replaced radiator so maybe the rest of the cooling system will start to fail shortly. Anything that I should be looking for/listening regarding the system when it is starting to go bad?
 
Ok good idea. I believe previous owner replaced radiator so maybe the rest of the cooling system will start to fail shortly. Anything that I should be looking for/listening regarding the system when it is starting to go bad?
If you do the job yourself, it’ll cost approximately $600 in parts for rad, water pump, stat, stat housing, temp sensor, all new hoses, water inlet pipe. Rad and water pump is about $400 of that $600.

If the temp display starts going past 210 then it’s prob time to replace things.

Edit: also fan clutch. Might as well swap in a new serpentine belt while you’re in there too.
 
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Ok good idea. I believe previous owner replaced radiator so maybe the rest of the cooling system will start to fail shortly. Anything that I should be looking for/listening regarding the system when it is starting to go bad?

Coolant leaks or unstable / spiking temperatures and overheating.
 
My 06 has about 50k miles. I ordered the stant kit and replaced the thermostat and temperature sender. I drilled the 1/8 hole as advised. I replaced the lower hose and that was an adventure until I found a remote flat spring clamp tool. I also drained the block. I slowly filled the radiator until it quit gurgling. I got about 2 1/4 gal of g05 in ti. So I start it up with the cap off and it just sits there about 190. I turned the air on and may have got it to 200. I cant see the turbulence when the thermostat opens but it doesn't get any hotter and I turned it off. I turned the key on after it sat a few minutes snd the gauge read 210. If that thermostat wasn’t opening, i think that engine would have really heated up but I don’t understand that water not moving in the radiator.
 
My 06 has about 50k miles. I ordered the stant kit and replaced the thermostat and temperature sender. I drilled the 1/8 hole as advised. I replaced the lower hose and that was an adventure until I found a remote flat spring clamp tool. I also drained the block. I slowly filled the radiator until it quit gurgling. I got about 2 1/4 gal of g05 in ti. So I start it up with the cap off and it just sits there about 190. I turned the air on and may have got it to 200. I cant see the turbulence when the thermostat opens but it doesn't get any hotter and I turned it off. I turned the key on after it sat a few minutes snd the gauge read 210. If that thermostat wasn’t opening, i think that engine would have really heated up but I don’t understand that water not moving in the radiator.
Does the upper radiator hose get hot? If it does then the thermostat should be opening. Check the fluid level in the radiator after the engine cools down. Sounds like it’s circulating. Did you fill your reservoir tank midway between add and full?
 
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Does the upper radiator hose get hot? If it does then the thermostat should be opening. Check the fluid level in the radiator after the engine cools down. Sounds like it’s circulating. Did you fill your reservoir tank midway between add and full?
Does the upper radiator hose get hot? If it does then the thermostat should be opening. Check the fluid level in the radiator after the engine cools down. Sounds like it’s circulating. Did you fill your reservoir tank midway between add and full?


I didn’t put any coolant in the reservoir tank yet. I will do that and check that upper hose temp. Thanks.
 
Filled the resovoir to midway. upper hose gets nice and hot. Temp sets and idles with the air on just about on the 2 of 210. I an going to call it good. Appreciate the help
 
Filled the resovoir to midway. upper hose gets nice and hot. Temp sets and idles with the air on just about on the 2 of 210. I an going to call it good. Appreciate the help
Just verify that the rad is full when the engine is cold and should be good to go
 
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136k on mine and I just replaced the coolant. My TJ runs at 210. I can see/feel the thermostat opening and am sure I have a195. It does not go above 210, but sits on the "1". Does the TJ waterpump have a hole in it for when it starts to fail you get a little drip on the floor?
 
Just had the entire cooling system overhauled in the 2001 TJ I just got (121k). Temp has started spiking into red (260) suddenly then dropping off at stop.

Had it done professionally because of limited free time and needing to do some work on my other vehicle. This thread was super helpful for it.

I had them make sure to put in a Mopar radiator and quality parts. So far, temp steady at about 195-200 when moving and up to 210 at stop and idle.

Only negative is they used worm gear clamps for the hose replacement. Don't think it is worth trying to replace them again at this point. Might see if they still have the stock constant tension ones they took off tomorrow at the shop to keep for future use.
 
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Thought I'd report here. After 20K miles, my O'Reilly's POS radiator has spring a leak at the bottom tank along the crimp. Do yourself a favor and take Chris's advise and get a Mopar unit. I'm not even going to try and attempt to warranty this piece of crap! Not worth the hassle.
Why I like rebuilding your OE all metal piece. Plastic does not belong in underhood conditions...
 
The old one can be cleaned up painted and reinstalled in a new pump with some thread sealer, or if it's rusted out there are nos pipe available from vendors and wholesellers.
 
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