2006 TJ 4.0 Rubicon overheating issues

[TurboTJ]

I don’t believe that you have said whether you have pressure tested your cooling system. The way you have described how it is performing (gets to 214 then quickly flashes to full scale) suggests to me that it will not hold pressure. I had that happen, first with a cracked radiator and then with a bad cap.

BTW, running with the heater full on does nothing to further flush the system. Coolant is always flowing through the heater core.

 

[JPHikr]

Here is how well the auxiliary radiator in my FSJ works:

Just checked the temps with my IR Thermometer.

The temp difference from the outlet on the water pump to the inlet on the intake manifold is 40 degrees cooler (with the Radiator showing 185) after flowing thru the heater core.

That was sitting idling for 5 minutes (with NO air flow thru the heater core.) after driving 10 miles.

 

[Piros1]

Thanks but the thermostat is gutted at this time and I’m pretty sure there is no air in the system. I have been all over the hills with it.

 

[Piros1]

I don’t believe that you have said whether you have pressure tested your cooling system. The way you have described how it is performing (gets to 214 then quickly flashes to full scale) suggests to me that it will not hold pressure. I had that happen, first with a cracked radiator and then with a bad cap.

BTW, running with the heater full on does nothing to further flush the system. Coolant is always flowing through the heater core.

No I have not pressure checked my system, I do not have the equipment with me to do this. But if I had a system that would not hold pressure I would be losing coolant and I have never had to add any. The system was pressure checked about a month ago after the new water pump was installed. Note I have replaced the cap.

 

[someguysjeep]

cheapest place i can find a Mopar radiator that says it fits my 04/auto, is Rock Auto for 279$ anybody know a better source?

mine decided to take a shit today.

any Mopar site brings up 2 units 504$ and 304$ but also have some BS about min order size of 25 units?
the RA part is the same stock # as the 304$ unit and says Mopar
the jeep shacks are way up between 500-800 and not even sure if its a real OE product.

 

[Piros1]

cheapest place i can find a Mopar radiator that says it fits my 04/auto, is Rock Auto for 279$ anybody know a better source?

mine decided to take a shit today.

any Mopar site brings up 2 units 504$ and 304$ but also have some BS about min order size of 25 units?
the RA part is the same stock # as the 304$ unit and says Mopar
the jeep shacks are way up between 500-800 and not even sure if its a real OE product.

Thanks we purchase a lot of parts for our smaller trucks from Rock Auto if time allows. I will check into it if the fan and shroud doesn’t work.

 

[JLANEF]

Piros1, I live here in Az and have a 1999. I have chased heat issue off and on also. I agree with Jerry on aftermarket all the way. I also am a little confused in going through the thread. Are you unhappy with 214 as a temp on the road and the trails here in Az? I think that is normal. Pegging out is always bad, but I was curious about the 214. My family lives in Missouri also. I am in Sun Lakes, Western East Valley and run north of Florence mostly. I’m hoping for relief when you get the shroud and fan. Jeff

 

[JLANEF]

Don’t want to hijack the post, but since we are exploring this heating issue, has anyone had and good results, (or bad), with adding the aluminum vents on top of the hood and cutting the holes in the hood under them? It seems like it would help, but never seen much real results either way!

Piros if I can help in any way let me know. Jeff in Chandler.

 

[Jerry Bransford]

Hood vents have little to no effect on the engine temperature.

 

[Piros1]

Yes I am concerned about the 214* plus temps I am seeing because it use to not be that high. The Jeep use to hover right around 200* or so until my heat issues started. This at home in MO too. I thought we had it corrected before I left home but I did not have a lot of drive time in it before we left. I was running out of my window of time to come spend some time here and get back home before 6/05/2021. I have been extremely busy for the past year building a new shop at home.
When the temps hit 214 depending on what type and where I am driving it isn’t long before it will start to climb and if I’m not on top of it is in the red.
It happened today going up the mountain on the highway to Yarnell. I fought it as it just started to climb and got to the side of the road quick enough that shortly after opening the hood my wife said the temps started to drop quickly. We were not using the AC at all today.
I did try spacing the hood open about two inches and strapping it down and that didn’t really do much I don’t think. It didn’t overheat again but managed to climb little above the 214 4-5 degrees as best I can tell by the gauge.
Sorry about the book just trying to give all the details. We will have a better idea after the parts arrive and I get them changed out.
What part of MO are you from?

Don’t want to hijack the post, but since we are exploring this heating issue, has anyone had and good results, (or bad), with adding the aluminum vents on top of the hood and cutting the holes in the hood under them? It seems like it would help, but never seen much real results either way!

Piros if I can help in any way let me know. Jeff in Chandler.

I personally have not tried that but I noticed yesterday when it started to overheat my wife said as soon as in opened the hold the temps started to drop. I blocked the hood open about 2” and strapped it down for the rest of the day. I did not overheat but it still ran pretty warm on hard pulls up the highway.

 

[Piros1]

Hood vents have little to no effect on the engine temperature.

I think I somewhat agree with this comment after my experience yesterday. But expelling excess heat from under the hood doesn’t hurt anything unless you run in extreme cold temperatures.

 

[Jeeper1]

The winch is not causing any problems for the cooling system. None. If you go back to a 100% factory Mopar stock cooling system your overheating issues will go away. Absolutely.

Aftermarket radiators are worse than a crapshoot, only the most expensive ones will even come close to how well the single row all aluminum core Mopar design works. 195 degree thermostat, Mopar water pump. Serpentine belt driven fan, heavy duty fan clutch.

And no, more rows in a radiator do not usually mean better cooling. In fact the TJ was originally introduced with a 2 row radiator but the design was soon changed to a 1 row radiator with better cooling characteristics.

Electric fans are a PITA. They don't cool as well and they're far more likely to fail. Seriously.

I live and wheel in the hot southwest (mostly desert) and if the factory cooling system wasn't up to it we would all be running something else. But we're not.

Not. I've been running down the exact same issue for over a year with a team of certified Jeep mechanics with everything stock and OE replacements.

 

[Jerry Bransford]

Not. I've been running down the exact same issue for over a year with a team of certified Jeep mechanics with everything stock and OE replacements.

If you say so lol. Somebody simply doesn't know what they're doing. The OEM cooling system is well known to have zero problems keeping the engine temperature where it should be in hot conditions with even a huge winch mounted in front. P. S. Understand that because a cooling system part includes OE or OEM in its ad or description does NOT mean it's an actual OEM part. It only means it will will fit in place of the original OEM part. This is especially the case for those buying a radiator claiming to be "OEM" when it's nothing more than a cheap aftermarket or store brand. Only a Mopar radiator is a true OEM radiator. And so far, the Holy Grail of radiators that cools as well as the Mopar while being reasonably priced has not yet been found.