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2004 TJ overheating problem

OP
T

Tj jeep

New Member
Jun 7, 2019
5
Cape Coral Fl
I have a 2004 wrangler 4.0 automatic I’ve had an overheating problem I’ve put new water pump new thermostat new 3core aluminum radiator I’ve bypassed heater core to see if that was an issue found out have a small leak. I’ve flushed out radiator engine and heater core and put new antifreeze back in if I sit at idle temp goes up to 212 215 and will stay there tell I start driving and when I get up to higher speed it will get hotter then I will turn heater on and it will go back to 212 degrees. I’ve had this issue for a few years now I can only drive it short distance. The only thing that I haven’t replaced is the fan clutch or would you recommend removing the fan and putting electric on
 

Chris

Administrator
Staff Member
Sep 28, 2015
38,128
Salem, Oregon
The only thing that I haven’t replaced is the fan clutch or would you recommend removing the fan and putting electric on
No, putting an electric fan on would be a horrible, stupid decision. That will likely just lead to more issues.

That 3-core "aluminum radiator" is probably part of the issue. Those things are known to be problematic, so I can't rule that out as part of the issue. You should be using a genuine OE Mopar radiator in all honesty.

Still, running at those temps isn't abnormal. What is the highest it gets up to?

Also, have you checked the radiator when the engine is cool to make sure it's full?
 
OP
T

Tj jeep

New Member
Jun 7, 2019
5
Cape Coral Fl
No, putting an electric fan on would be a horrible, stupid decision. That will likely just lead to more issues.

That 3-core "aluminum radiator" is probably part of the issue. Those things are known to be problematic, so I can't rule that out as part of the issue. You should be using a genuine OE Mopar radiator in all honesty.

Still, running at those temps isn't abnormal. What is the highest it gets up to?

Also, have you checked the radiator when the engine is cool to make sure it's full?
The temp gets up to red line and I’m losing fluid back in reservoir I’ve also put on a new radiator cap.. I put the aluminum radiator in cause the original radiator I thought was bad cause I was over heating then
 

Dan_man

Member
Supporting Member
May 5, 2019
46
Tracy,ca
I would put an oem t-stat in first then burp the system and make sure there is no air at all I’m it. You can use something like this EPAuto Spill Proof Radiator Coolant Filling Funnel Kit https://www.amazon.com/dp/B01I40ZQWE/?tag=wranglerorg-20 to burp the air out. It sounds your over heating wile driving and not at idle so it’s not the fan. I would check the inlet and outlet temps of your radiator. Just to make sure it’s cooling properly.
 
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Quigley

TJ Enthusiast
Oct 20, 2018
153
Kingston, WA
I have a Mopar water pump, stock 195 thermostat, and stock Mopar radiator and never hit 205 even with long highway drives. It’s always below the middle. I’d suspect radiator as others have said. Mopar equipment is cheaper and lasts 100k miles

You can burp your system by having the cap off your radiator and running the vehicle. You’ll need to run it until the thermostat opens. You’ll see air bubbles coming to the surface of the radiator. Add fluid as needed to reservoir and radiator. You can also squeeze the upper radiator hose to force air out. This won’t get everything out, but should get any large pockets out of the system.

Are you losing coolant or have coolant in your oil? Your heater core is leaking so you bypassed it?
 
OP
T

Tj jeep

New Member
Jun 7, 2019
5
Cape Coral Fl
I have a Mopar water pump, stock 195 thermostat, and stock Mopar radiator and never hit 205 even with long highway drives. It’s always below the middle. I’d suspect radiator as others have said. Mopar equipment is cheaper and lasts 100k miles

You can burp your system by having the cap off your radiator and running the vehicle. You’ll need to run it until the thermostat opens. You’ll see air bubbles coming to the surface of the radiator. Add fluid as needed to reservoir and radiator. You can also squeeze the upper radiator hose to force air out. This won’t get everything out, but should get any large pockets out of the system.

Are you losing coolant or have coolant in your oil? Your heater core is leaking so you bypassed it?
The radiator is new 3 core aluminum new water pump new thermostat 160 degrees new hoses and new radiator cap I let it burp for 45 minutes with heater on i checked the clutch fan it speeds up when accelerate and slow down when letting off I do have small leak in heater core.... at idle it stays at 210 once I put the cap on and drive it it goes up to in temp drive about 10 miles it goes up to 240 and over... I’ve checked oil to see if any radiator fluid is on dip stick and no there’s not... I’ve checked to see if there any coming out of exhaust no smell no moisture coming out.... I took the OEM radiator out cause it was bad and that’s when I replaced water pump and put a 195 thermostat in..This has been an on going issue the last three years it wasn’t as bad through the couple years but now I can’t go over 10 miles
 
OP
T

Tj jeep

New Member
Jun 7, 2019
5
Cape Coral Fl
The radiator is new 3 core aluminum new water pump new thermostat 160 degrees new hoses and new radiator cap I let it burp for 45 minutes with heater on i checked the clutch fan it speeds up when accelerate and slow down when letting off I do have small leak in heater core.... at idle it stays at 210 once I put the cap on and drive it it goes up to in temp drive about 10 miles it goes up to 240 and over... I’ve checked oil to see if any radiator fluid is on dip stick and no there’s not... I’ve checked to see if there any coming out of exhaust no smell no moisture coming out.... I took the OEM radiator out cause it was bad and that’s when I replaced water pump and put a 195 thermostat in..This has been an on going issue the last three years it wasn’t as bad through the couple years but now I can’t go over 10 miles
And the coolant only goes in the reservoir and once it cools down it goes back into the radiator
 

Quigley

TJ Enthusiast
Oct 20, 2018
153
Kingston, WA
Who makes the radiator? Is it the 160 thermostat or the stock 195 now? I’ve never had a coolant problem using mopar radiators so I’m leaning towards the 3 core radiator which have been known to cause problems. When you installed the radiator did you lay the fan clutch down or prop it upright. It gets fudged up if you lay them down. There is a check for the fan clutch, but I can’t remember it. I think it’s if you can spin the blade freely with engine off, but I’d confirm that. What mix of antifreeze are you using? Your in butt hot Florida so I can imagine this is frustrating, but stay at It. What pound pressure is your radiator cap? Is there fluid leaking from the coolant system somewhere? Water pumps can sometimes be difficult to seal properly and leaks can go undetected. What waterpump did you install? Our shit loves mopar and parts store brands can sometimes cause issues. That’s all I can think at the moment
 

TurboTJ

TJ Enthusiast
Supporting Member
Jan 5, 2019
190
Walnut Creek, CA
I had overheating problems and discovered the radiator cap was bad. I replaced it with what I think was a Crown part. Still overheated. So I replaced it again with a Stant part. Still overheated. So I replaced it again with the Mopar OEM part. No more overheating problems.
 
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mendomadman

New Member
Jun 14, 2019
4
Mendocino County, CA
My '04 LJ runs a bit warm too. I replaced what I though was a leaky water pump, but it seems to seep still perhaps from bolts that go through water pump into water jacket. Autozone water pump had a different style impeller, one that looks like an alternator fan vs one I replaced that is closed and round like a conventional centrifugal pump. I think the conventional stye might be better. I bought a lower temp thermostat which I haven't yet installed. A couple of thoughts: The fan clutch should be fairly easy to turn when cold, and should be pretty well locked up if engine and radiator is hot. Try turning fan cold and hot by hand with engine off. Do you have a big blockage in front of grille? Bugs on A/C condenser? I have had some success over the years with Redline Water Wetter. It is an additive which increases heat transfer capability of coolant. Pure water is a better coolant than pure antifreeze, so don't run a higher concentration than you need for freeze protection. I would check for a bad head gasket. If when you were purging for 45 minutes, was it still blowing bubbles? If combustion gases are getting into the cooling system, overheating will follow. Sometimes head gasket leaks don't show up on a cool engine. I think there are test kits for the presence of combustion gases in the coolant. I've never used one, but have seen lots of bad head gaskets that could be diagnosed without a coolant test. Have you tried running premium? If your ECM is running a lot of spark advance, or if the engine is running lean, even on one cylinder, that could show up as overheating.
Hope this helps. Let me know what cures your Wrangler, as I may end up with the same problem.