How can I keep engine temps down?

[Willys41]

I often see 240+ in the scorching Summers here in Las Vegas, especially when going uphill. I have been very tempted to use Water Wetter, but I'm one of those owners who religiously avoids gimmicky additives that don't work or can even cause damage.

I suspect this isn't the case for Water Wetter, but I would like to know how much you add to your engine coolant and about how much it reduces your engine temps. Seems like this could be a cheap/easy way to bring temps down, but I've been a little hesitant because cheap/easy never seems to work out well. Love to hear some testimonials from you and others who use this product regularly. Thanks in advance and appreciate your insight.

From what I have read water wetter can help and I use it in my jeep put in the case of the Wrangler It a rad. fan issue.
I had the same 235+ temps pulling hills and spent 6 months trying different things to lower the high temps.
RPM Extreme JL fan controller is the answer.
After the install the highest temp I have seen is 212 pulling a 8000 mountain pass.
Jon builds them for JKs AND JLs.

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[Kracka]

Yep...I've also been a Redline customer for many years and strictly used their oil in our old imports. This is why I assume that Water Wetter actually works to some extent and why I've been considering it for my JL.

I assume that the bottle you add to the JL's coolant is the standard 12 ounce, correct?

I know that drivers of other vehicles also change the water to coolant ratio when using Water Wetter, but do you feel that's necessary for the 3.6L? Seems like this might only apply to high-performance or racing vehicles.

Lastly...about how much cooler are your engine temps with Water Wetter vs. without?

I edited my post above with some additional info.

I add one 12oz bottle to the stock cooling system with the factory coolant. For a street car there is really no need to mess with the water/coolant ratio. For a climate like Vegas, you could run 60-70% water if you really wanted to...

The Pentastar V6 is perfectly content with the factory 50/50 + 12oz of RLWW.

In the brutal Dallas, TX summers it's rare I ever see a coolant temp above 206F even in traffic (mid-upper 190's is more typical). That's across 3 Pentastars and 1 turbo on the 4 Jeeps. We've towed plenty too, sometimes above the rated weight limit, and still no issues or coolant temp creep.

 

[flyer92]

I edited my post above with some additional info.

I add one 12oz bottle to the stock cooling system with the factory coolant. For a street car there is really no need to mess with the water/coolant ratio. For a climate like Vegas, you could run 60-70% water if you really wanted to...

The Pentastar V6 is perfectly content with the factory 50/50 + 12oz of RLWW.

In the brutal Dallas, TX summers it's rare I ever see a coolant temp above 206F even in traffic (mid-upper 190's is more typical). That's across 3 Pentastars and 1 turbo on the 4 Jeeps. We've towed plenty too, sometimes above the rated weight limit, and still no issues or coolant temp creep.

Thanks for the great info! With only the OEM coolant, my 3.6L routinely hits 220F in typical city traffic on flat roads, even during the winter. Would be great to see 206F and lower, so I think I'll try the Water Wetter after all. If I experience that sort of improvement in oil temps, then it will save me from investing in other expensive options. Look forward to trying this out and I appreciate your insights. Happy Jeepin'!

 

[Willys41]

I edited my post above with some additional info.

I add one 12oz bottle to the stock cooling system with the factory coolant. For a street car there is really no need to mess with the water/coolant ratio. For a climate like Vegas, you could run 60-70% water if you really wanted to...

The Pentastar V6 is perfectly content with the factory 50/50 + 12oz of RLWW.

In the brutal Dallas, TX summers it's rare I ever see a coolant temp above 206F even in traffic (mid-upper 190's is more typical). That's across 3 Pentastars and 1 turbo on the 4 Jeeps. We've towed plenty too, sometimes above the rated weight limit, and still no issues or coolant temp creep.

is your a/c on. If so your radiator fan will be running keeping the temps down.

 

[Kracka]

is your a/c on. If so your radiator fan will be running keeping the temps down.

When it's 110F outside sitting in stop & go traffic under the Texas sun, you bet it is!

The AC and radiator fans are a constant variable in this.

 

[dsgrey]

I edited my post above with some additional info.

I add one 12oz bottle to the stock cooling system with the factory coolant. For a street car there is really no need to mess with the water/coolant ratio. For a climate like Vegas, you could run 60-70% water if you really wanted to...

The Pentastar V6 is perfectly content with the factory 50/50 + 12oz of RLWW.

In the brutal Dallas, TX summers it's rare I ever see a coolant temp above 206F even in traffic (mid-upper 190's is more typical). That's across 3 Pentastars and 1 turbo on the 4 Jeeps. We've towed plenty too, sometimes above the rated weight limit, and still no issues or coolant temp creep.

In DFW stop and go traffic I'll see mine hit 220F at times before it quickly drops. I replaced my coolant reservoir in late October and was watching at that time too, would still hit 220F at times even in the low 80s. I've never considered it an issue since other vehicles I've owned have performed the same.

 

[Willys41]

When it's 110F outside sitting in stop & go traffic under the Texas sun, you bet it is!

The AC and radiator fans are a constant variable in this.

Try driving without the A/C and you will find your temps rise to at least 231 degrees.
The fan comes on at 15% fan speed at 221 and 75% fan speed at 231 degrees and if you put a load on it you may see even higher temps.

 

[Kracka]

Try driving without the A/C and you will find your temps rise to at least 231 degrees.
The fan comes on at 15% fan speed at 221 and 75% fan speed at 231 degrees and if you put a load on it you may see even higher temps.

I'd rather not... Sounds miserable.

 

[Willys41]

I'd rather not... Sounds miserable.

Here in California we see a lot of 70 to 80 degrees day and run with best top sun rider open no A/C and before the fan controller I would see 235+ on both my Wranglers.
The RPM Extreme has lowered my coolant and oil temps by 25+ degrees.

 

[jellis4148]

Here is an example and a question. Driving to California going up the long steep grades of northern cali the oil would hit 240+ and the coolant would hit 235+. I had the A/C going so the fan should've been working full blast. The RPM's were around 3,000-3,500. How would the RPM Extreme have helped me? 2019 Rubicon on 37's with stock 4.10 gears. Not being a smart ass, cause I really would like to not see those temps again. Just a genuine question.

 

[Willys41]

Here is an example and a question. Driving to California going up the long steep grades of northern cali the oil would hit 240+ and the coolant would hit 235+. I had the A/C going so the fan should've been working full blast. The RPM's were around 3,000-3,500. How would the RPM Extreme have helped me? 2019 Rubicon on 37's with stock 4.10 gears. Not being a smart ass, cause I really would like to not see those temps again. Just a genuine question.

I have the same set up put with 4.88s 37s and weigh in at 6600lbs. fully loaded with gear.
Coming back from Moab pulling a 4000ft to 8000ft mountain pass I only hit 212 coolant and 225 oil.
In Moab and Sand Hollow 208 was tops.
You A/C will kick on the fan as needed for cooling the condenser. Not necessarily high speed.
I have had the same results with both my 2018 Rubicon JL and my 2020 Willys. Coolant and oil down by 25+ degrees.
Here is the fan speeds with the RPM fan controller.

Fahrenheit
195 degrees = 15%
199 degrees = 30%
205 degrees = 50%
212 degrees = 75% This is the highest I have seen
218+ degrees = 100%
I ordered mine with the positive tiger 100% high speed by pass put have never had to use it.

It is impotent to note that factory set up at 231 degrees you fan is only spinning at about 75% fan speed.

 

[roaniecowpony]

Here is an example and a question. Driving to California going up the long steep grades of northern cali the oil would hit 240+ and the coolant would hit 235+. I had the A/C going so the fan should've been working full blast. The RPM's were around 3,000-3,500. How would the RPM Extreme have helped me? 2019 Rubicon on 37's with stock 4.10 gears. Not being a smart ass, cause I really would like to not see those temps again. Just a genuine question.

I'm on 37s, lift, etc. When I climb a pass on I-15 between the LA basin and the high desert, my temps have gone to 235F coolant and 245F oil on a 65F day and continued climbing until I slowed down.

My mods to address this condition are the Gladiator 850w fan, Gladiator(392, etc) larger grill mesh, o/s Mishimoto radiator, and the RPM Extreme fan controller. The oil temperature will track with coolant temperature with some hysteresis, because the coolant is used in the "oil cooler" heat exchanger to cool the oil. My coolant and oil temps are down about 20F across the board in all situations.

 

[Deleted User 38384]

On vacation in Gatlinburg. Our place is up Ski Mountain Drive near Ober Mountain for those aware with the area. Probably like a 1,000 foot climb up from Gatlinburg. Checked temps when we got up to the condo last night and both coolant and oil were about 225F last night. Ran it in auto but not sure what gear it was, running about 2,000-2,500 RPMs coming up. I know I was not at a critical temp or anything, just curious how to keep the temps lower or should I just roll with it.

Will downshifting and running the RPMs higher help with cooling the 3.6?

Ahhhh, 225°f is not hot.

If you were running 250°f+, then you might want to start looking into it, but 210-235°f is normal operating temperature when your engine's been working.

 

[Willys41]

I'm on 37s, lift, etc. When I climb a pass on I-15 between the LA basin and the high desert, my temps have gone to 235F coolant and 245F oil on a 65F day and continued climbing until I slowed down.

My mods to address this condition are the Gladiator 850w fan, Gladiator(392, etc) larger grill mesh, o/s Mishimoto radiator, and the RPM Extreme fan controller. The oil temperature will track with coolant temperature with some hysteresis, because the coolant is used in the "oil cooler" heat exchanger to cool the oil. My coolant and oil temps are down about 20F across the board in all situations.

Ahhhh, 225°f is not hot.

If you were running 250°f+, then you might want to start looking into it, but 210-235°f is normal operating temperature when your engine's been working.

I have not seen any motor running as hot as the Wranglers.
My tundra and F250 run about 190 and I only see 212 with my F250 pulling a hill with my trailer and my jeep on the trailer.

 

[RicRecon]

Does the RPM fan controller work for the 3.0 diesel engine too? If so, I may try it

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