Cooling System Observations

[SCJeeps]

Quick observation to those concerned about coolant temps. I just changed my factory plastic bumper for a Next Venture Motorsports Adventure Series…the catch at this moment is I don’t have a winch installed.

What I observed was that my coolant temps jumped 10-15 degrees from this change alone. I have been running and observing coolant temps for probably close to 2 years and my Jeep normally runs 195-205 with excursions up into the teens if I am pulling hard up a grade, etc . My normal temps came after I swapped to the Gladiator grill inserts (open honeycomb) several years ago.

Clearly directing air flow to the radiator is critical in this system. Looking closer at the new bumper I can see a clear path over the top of the bumper and down underneath the radiator near the sway bar disconnect motor. As I said the only change I made was the bumper swap. All those plastic air dams have a purpose ! I may try to fab up an air dam/ deflector just for some testing but ultimately it won’t matter until I get a winch installed and see how the system behaves.

As you can see in the photo my grill is not obstructed at all, in fact it theoretically is more open than before but the results speak for themselves.

Before

After

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[AA_Jeeper]

This is very interesting, albeit hard to understand how it made that big of a difference.

 

[AA_Jeeper]

Theory- the lower air dam now has holes where in the past it was solid. The solid portion would have created a stagnant pocket with moving air behind it. Moving air, being lower pressure, could create a suction behind the lower dam and draw the hotter air away. This is me stretching my brain to figure out why this would have changed temps.

 

[AA_Jeeper]

If you're monitoring I'd be super interested in just taping over the lower air dam holes as a test.

 

[SpectreH]

It is interesting that the new bumper had that much impact on aerodynamics and the resulting airflow through the radiator.

I watch temps on mine as well. On a very hot day and normal highway cruising, I see 195 to low 200’s for coolant temps and around 210 for oil. I also noticed that the analog coolant temp display on my 4xe is more of a dummy gauge. Always shows just under half way starting around 180ish.

My 911 behaved that way as well, but I reprogrammed the display to give me actuals. The analog gauge and digital readout would hit 194 and stay there. It now reads correctly. I wonder if the Jeep analog display can be reprogrammed?

I was surprised how high our Jeep oil temps are compared to the Porsche. In sport mode at 80 mph on a 100 degree day, the oil is at 198-199. (Normal mode jumps up to our Jeep temps and coolant goes from 183 to 210-215). I guess normal is about meeting EPA mandated pollutant mandates.

 

[SCJeeps]

I’m going to try to create a blocking plate and see how it changes the temp behavior. Here is a photo of access where I don’t currently have a winch.

I’ll also try blocking the lower skid plate as well.

 

[SpectreH]

Hoping you easily get the airflow sorted.

 

[SCJeeps]

I created a blocking plate and installed. So far it seems to have improved cooling. I will continue to monitor temps. .

 

[Wabujitsu]

In 97-101 ambient temperatures in humid and flat Florida, at 70-80 MPH I’m at 210-215 for coolant temps. This is my front end configuration, 2.5” lifted JLUR 2.0 on 35s.

While accelerating, temps will go a few degrees higher, but then settle down quickly at cruising speed. It never goes above 197 while idling in full sunlight indefinitely.

From my research, I am comfortable with these temps.

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