Coolant overheating while towing?

[bigcheeshead]

Update: I absolutely despise two local dealership here in Phoenix due to all the problems I had with warranty, see my previous post https://www.jeepgladiatorforum.com/forum/threads/why-do-chrysler-dealerships-hate-jeeps.64315/

So as much as it pained me, I was left with no choice but take the Jeep to another dealership as the coolant was averaging almost 240 degrees during regular highway driving and the solution I was given by offroad shops was to replace everything, water pump, radiator, thermostat etc.

If you’ve modified your Jeep and need dealer service, I would highly recommend Chapman Dodge in Scottsdale! Service Manager Abrian was amazing to work with and didn’t automatically blame mods as the cause. They spent a lot of time and effort going over everything in the Jeep to diagnose the issue. They’ve tested the engine block, radiator, water pump, thermostat and they all passed. Ultimately, they ended up power washing the radiator which had a lot of dirt from 4 years of trails. They noticed a lot of air in the lines and burped the cooling system.

Problem solved….for two weeks! The temps were around 200 never exceeding 209! Then two weeks later temps are elevated again although not as high, averaging around 220. Nothing changed, I didn’t even offroad! The ultimate test will be this weekend trying to tow the RV again. As someone pointed out earlier, 220 might've been the average temperature all alone for me before the spike.

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[willys 41]

Update: I absolutely despise two local dealership here in Phoenix due to all the problems I had with warranty, see my previous post https://www.jeepgladiatorforum.com/forum/threads/why-do-chrysler-dealerships-hate-jeeps.64315/

So as much as it pained me, I was left with no choice but take the Jeep to another dealership as the coolant was averaging almost 240 degrees during regular highway driving and the solution I was given by offroad shops was to replace everything, water pump, radiator, thermostat etc.

If you’ve modified your Jeep and need dealer service, I would highly recommend Chapman Dodge in Scottsdale! Service Manager Abrian was amazing to work with and didn’t automatically blame mods as the cause. They spent a lot of time and effort going over everything in the Jeep to diagnose the issue. They’ve tested the engine block, radiator, water pump, thermostat and they all passed. Ultimately, they ended up power washing the radiator which had a lot of dirt from 4 years of trails. They noticed a lot of air in the lines and burped the cooling system.

Problem solved….for two weeks! The temps were around 200 never exceeding 209! Then two weeks later temps are elevated again although not as high, averaging around 220. Nothing changed, I didn’t even offroad! The ultimate test will be this weekend trying to tow the RV again. As someone pointed out earlier, 220 might've been the average temperature all alone for me before the spike.

The real problem is very little to no air will pass though the radiator core wile driving down the road.
I proved this by installing a high volume high pressure pusher fan on the A/C condenser.
What I discovered was the air would pass through the condenser hit the radiator core and bounce off. Almost NO air would pass though the radiator core.
Your factory radiator fan comes on at 15% fan speed at 221 degrees and 75% fan speed at 231 and that's the problem. To little to late.
I found that the ONLY way to get air pass though the core was to pull or suck it though.
That where the RPM Extreme JL fan controller solved ALL my 235+ coolant temps and also lowered my oil temps by 25 degrees.
I now average 188 to 195 and pulling a 4000ft mountain pass topped out at 212 degrees.
Here is how the fan will work with the fan controller.


195 degrees = 15%
199 degrees = 30%
205 degrees = 50%
212 degrees = 75%
218+ degrees = 100%

 

[KevinC]

Ultimately, they ended up power washing the radiator which had a lot of dirt from 4 years of trails. They noticed a lot of air in the lines and burped the cooling system.

I will revert back to your first post and "your" mechanic. After your issues and taking it back to them and they said everything checked out; apparently it didn't. For them not to at least burp the system or clean the radiator, I would not trust the generic coolant is the right stuff.

I wonder why the dealership didn't flush the generic coolant out and replace with the right coolant?

 

[willys 41]

I will revert back to your first post and "your" mechanic. After your issues and taking it back to them and they said everything checked out; apparently it didn't. For them not to at least burp the system or clean the radiator, I would not trust the generic coolant is the right stuff.

I wonder why the dealership didn't flush the generic coolant out and replace with the right coolant?

Its not the coolant. Its fan timing and fan speed.
Let you jeep idle for 15-20 minutes on a warm day. You will find that the radiator fan will only start to come on at 15% fan speed at 221 degrees and wont come on to the higher speed of 75% until you hit 231 degrees. To little to late.

 

[PuddleJumper]

Its not the coolant. Its fan timing and fan speed.
Let you jeep idle for 15-20 minutes on a warm day. You will find that the radiator fan will only start to come on at 15% fan speed at 221 degrees and wont come on to the higher speed of 75% until you hit 231 degrees. To little to late.

I need to get rpm extreme controller. So far I've just been cheating with my Tazer and putting it in Cooldown mode (locked 100% fan speed) when towing offroad or severe grade. but i'd really like a set and forget system.

 

[KevinC]

Its not the coolant. Its fan timing and fan speed.
Let you jeep idle for 15-20 minutes on a warm day. You will find that the radiator fan will only start to come on at 15% fan speed at 221 degrees and wont come on to the higher speed of 75% until you hit 231 degrees. To little to late.

I get what you are saying but he didn't have the problem before the mechanic did his magic. I assume he would want his Jeep to get back to where it was prior to the shop working on it. Cooling it with an aftermarket fan is not the solution to the mechanic infused problem.

Jeeps in general have always ran hot. The 4.0L in the TJ/ZJ/XJ was always seeing 210 degrees and everyone thought putting a 185 thermostat was a solution soon found out it wasn't. They were designed to run 210. The 3.6 Penstar have been known to do the same. It may seem like it runs hotter than other engines but maybe it is designed that way. Either way, he shouldn't have to resort to aftermarket products to get his Gladiator back to where it once was.

 

[willys 41]

I get what you are saying but he didn't have the problem before the mechanic did his magic. I assume he would want his Jeep to get back to where it was prior to the shop working on it. Cooling it with an aftermarket fan is not the solution to the mechanic infused problem.

Jeeps in general have always ran hot. The 4.0L in the TJ/ZJ/XJ was always seeing 210 degrees and everyone thought putting a 185 thermostat was a solution soon found out it wasn't. They were designed to run 210. The 3.6 Penstar have been known to do the same. It may seem like it runs hotter than other engines but maybe it is designed that way. Either way, he shouldn't have to resort to aftermarket products to get his Gladiator back to where it once was.

That's the problem.
Any modified jeep like mine at 6400lbs or towing the factory cooling system is antiquity with the proper fan controller. And I am not talking about a aftermarket fan.
RPM Extreme JL fan controller turns on the fan at lower temps and contuse to speed up as temps rise.
195 degrees = 15% fan speed
199 degrees = 30% fan speed
205 degrees = 50% fan speed
212 degrees = 75% fan speed
218+ degrees = 100% fan speed
Unlike the factory set up the fan will only come on at 15% fan speed at 221 and 75% fan speed at 231
Not enough with our modified Jeep pulling heavy loads.

 

[smlobx]

Time for a new shop. Generic coolant is for people that are too lazy or stupid to use the right stuff. Do you use them for your oil changes too? No telling' what they are using there. I'm a retired ASE master tech and I've attended a butt load of seminars and classes and have never had one where they recommended " generic" fluids in a modern vehicle.

This is correct. The days of using a “generic” coolant was over about 15 - 20 years ago. Today the various coolants used are specific to the metallurgy of the engine. Always use OEM coolant in every vehicle you have. No Exceptions.

 

[smlobx]

That's the problem.
Any modified jeep like mine at 6400lbs or towing the factory cooling system is antiquity with the proper fan controller. And I am not talking about a aftermarket fan.
RPM Extreme JL fan controller turns on the fan at lower temps and contuse to speed up as temps rise.
195 degrees = 15% fan speed
199 degrees = 30% fan speed
205 degrees = 50% fan speed
212 degrees = 75% fan speed
218+ degrees = 100% fan speed
Unlike the factory set up the fan will only come on at 15% fan speed at 221 and 75% fan speed at 231
Not enough with our modified Jeep pulling heavy loads.

Just a side thought… it seems that the Ecodiesel guys are having problems towing in the summer and I wonder if the product you mentioned would help them out. I looked at their website but they say it hasn’t been tested on diesels… Maybe someone should be a guinea pig…

 

[willys 41]

Just a side thought… it seems that the Ecodiesel guys are having problems towing in the summer and I wonder if the product you mentioned would help them out. I looked at their website but they say it hasn’t been tested on diesels… Maybe someone should be a guinea pig…

Let me tell you how this all started with me. I was looking for a way to control the rad. fan and my 235+ coolant temps.
I was on the RPM EXTREME website and saw that Jon was making fan controllers for JKs and I ask him if he could make one for my 3.6 JL.
He got right on it and in a few weeks he had one and tested it on a JL and he could send me one.
At that time he was only making them for the 3.6 put with some help from others on the Gladiator and Wrangler forum he has made ones for other engines.
I think its only a mater of time before he has one for the Ecodiesel and I know they will be HAPPY diesel.

 

[bigcheeshead]

I will revert back to your first post and "your" mechanic. After your issues and taking it back to them and they said everything checked out; apparently it didn't. For them not to at least burp the system or clean the radiator, I would not trust the generic coolant is the right stuff.

I wonder why the dealership didn't flush the generic coolant out and replace with the right coolant?

Agree, the mechanic that did the initial work repairing the coolant line is incompetent. Unfortunately, they were the only ones open on a late Sunday afternoon before my big trip. The dealership did mention that there is really not that much of a difference between different coolants and didn't think replacing the coolant would solve the problem.

 

[bigcheeshead]

I need to get rpm extreme controller. So far I've just been cheating with my Tazer and putting it in Cooldown mode (locked 100% fan speed) when towing offroad or severe grade. but i'd really like a set and forget system.

Awesome idea!!! Thank you @PuddleJumper for pointing out the Tazer Cooldown mode. I'm going to try it and see how it does while towing. I wonder, if it would prematurely wear out the fan if I run at 100% with Tazer for 4+ hour drives.

 

[PuddleJumper]

Awesome idea!!! Thank you @PuddleJumper for pointing out the Tazer Cooldown mode. I'm going to try it and see how it does while towing. I wonder, if it would prematurely wear out the fan if I run at 100% with Tazer for 4+ hour drives.

It’s a brushless fan motor. You can’t hurt it in a noticeably measured way

 

[willys 41]

It’s a brushless fan motor. You can’t hurt it in a noticeably measured way

When I replace my 600 watt fan with the 940 watt fan I remove the 600 watt fan motor and keep it in my jeep along with other spare parts.
Its fairly small and easy to store.

 

[bigcheeshead]

It’s a brushless fan motor. You can’t hurt it in a noticeably measured way

I upgraded my tazer firmware yesterday to get the Cooldown feature and drove around town and highways for couple of hours with the fan at 100%. With 105 ambient temp here in PHX, I never went above 185 degrees on the coolant temp. One interesting discovery. The way Tazer tricks the system into turning on the fan to 100% is by spiking the transmission temp to 250 degrees which triggers the fan to run at 100%. It's a fake spike because the second you turn off Cooldown mode, tranny temps immediately drop to sub 200.

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