Coolant temperatures while towing

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

South VA

K2500 454 Long Roof
Supporting Member
Joined
Nov 2, 2022
Messages
960
Reaction score
3,281
Location
Dinwiddie County, Virginia
Wow! Had no idea that this thread would generate so much discussion! Y'all's comments and suggestions are helping me learn and read a bunch more about not only coolant temperatures, but also antifreeze types and mixtures, additives, water chemistry, and auxiliary fan and A/C operation relative to coolant temps, plus more.

And, as a bonus, I learned that monitoring transmission temperature is both doable and simple in my '96. :33: I love this place!!
 

GrimsterGMC

Supporting Member
Supporting Member
Joined
Nov 3, 2021
Messages
1,358
Reaction score
4,537
Location
New Zealand
Wow! Had no idea that this thread would generate so much discussion! Y'all's comments and suggestions are helping me learn and read a bunch more about not only coolant temperatures, but also antifreeze types and mixtures, additives, water chemistry, and auxiliary fan and A/C operation relative to coolant temps, plus more.

And, as a bonus, I learned that monitoring transmission temperature is both doable and simple in my '96. :33: I love this place!!
Never underestimate the shear wealth of knowledge here on this forum,and the willingness to share it with others. All you have to do is ask. :)
 

Erik the Awful

Supporting Member
Supporting Member
Joined
Aug 9, 2019
Messages
8,306
Reaction score
17,393
Location
Choctaw, OK
I thought the issue was NEVER to run ANY water as a stand alone coolant w/o some sort of additive package to provide corrosion protection and/or anti-cavitation protection (to name at least two). Check me if I'm wrong.
A lot of racing organizations don't allow anything but water in the cooling system. Most drag strips allow street driven cars to run antifreeze, but any car trailered in has to have straight water. Glycol is extremely slippery when spilled on the track.

For a street-driven car, you really need the corrosion protection. Straight water is the best coolant, but it allows too much corrosion and will crack your block in freezing weather.
 

1998_K1500_Sub

Nitro Junkie
Supporting Member
Joined
Jan 28, 2019
Messages
2,439
Reaction score
3,751
Location
Rural Illinois
A lot of racing organizations don't allow anything but water in the cooling system. Most drag strips allow street driven cars to run antifreeze, but any car trailered in has to have straight water. Glycol is extremely slippery when spilled on the track.

For a special-purpose vehicle, I can understand this.

I suspect even the "race guys" run some sort of corrosion inhibitor in their coolant water... maybe that Redline stuff(?).

Many years ago, a younger, dumber me ran distilled water w/o additives in a new engine for couple of weeks, and when I drained it from the system I was sorry to see the crap that came out. I won't ever do that again.
 

wb292

I'm Awesome
Joined
Oct 29, 2019
Messages
244
Reaction score
248
Location
Arizona
I have two 1995 K2500s with 454s. One Suburban and one RCLB. I live in Arizona where the temps can easily reach above the 120 mark in the summer. 126 is the hottest temperature I’ve seen in Bullhead city.
I’ve ran into this temp problem towing myself. My fix was to replace the water pump with a high pressure and high volume water pump along with a severe duty fan clutch and a 9 blade fan for a 2003 6.0 gas motor. The duramax blade won’t work because the hub dia is different. Also swap to a 180 deg thermostat and drill 2 3/32 holes in the flange to allow more water flow. I also swapped in a radiator for a 3500HD. It has the 2 3/16 think core instead of the 2inch. I can now tow easily and never get above 200 deg even in the summer . The aux fan switch is located in the passenger side head in the TBI. It’s set for 225. It never comes on anymore.
 

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
13,086
Reaction score
16,354
I have two 1995 K2500s with 454s. One Suburban and one RCLB. I live in Arizona where the temps can easily reach above the 120 mark in the summer. 126 is the hottest temperature I’ve seen in Bullhead city.
I’ve ran into this temp problem towing myself. My fix was to replace the water pump with a high pressure and high volume water pump along with a severe duty fan clutch and a 9 blade fan for a 2003 6.0 gas motor. The duramax blade won’t work because the hub dia is different. Also swap to a 180 deg thermostat and drill 2 3/32 holes in the flange to allow more water flow. I also swapped in a radiator for a 3500HD. It has the 2 3/16 think core instead of the 2inch. I can now tow easily and never get above 200 deg even in the summer . The aux fan switch is located in the passenger side head in the TBI. It’s set for 225. It never comes on anymore.

You're the first one I've heard mention a 6.0 fan, I may have to give that a whirl. Also, I just put on a Bullhead City t-shirt as my mom lives there. Your timing is uncanny.
 

L31MaxExpress

I'm Awesome
Joined
Apr 21, 2018
Messages
6,487
Reaction score
8,787
Location
DFW, TX
I have two 1995 K2500s with 454s. One Suburban and one RCLB. I live in Arizona where the temps can easily reach above the 120 mark in the summer. 126 is the hottest temperature I’ve seen in Bullhead city.
I’ve ran into this temp problem towing myself. My fix was to replace the water pump with a high pressure and high volume water pump along with a severe duty fan clutch and a 9 blade fan for a 2003 6.0 gas motor. The duramax blade won’t work because the hub dia is different. Also swap to a 180 deg thermostat and drill 2 3/32 holes in the flange to allow more water flow. I also swapped in a radiator for a 3500HD. It has the 2 3/16 think core instead of the 2inch. I can now tow easily and never get above 200 deg even in the summer . The aux fan switch is located in the passenger side head in the TBI. It’s set for 225. It never comes on anymore.
Duramax fan WILL work, but have to change the clutch. I have part numbers for both a spin on and 4 bolt clutch. The 4 bolt clutch does use a 3/4" pilot and needs a 5/8" to 3/4" adapter bushing to work.
 

wb292

I'm Awesome
Joined
Oct 29, 2019
Messages
244
Reaction score
248
Location
Arizona
Duramax fan WILL work, but have to change the clutch. I have part numbers for both a spin on and 4 bolt clutch. The 4 bolt clutch does use a 3/4" pilot and needs a 5/8" to 3/4" adapter bushing to work.
Please post the part numbers. I’m a machinist so making a bushing won’t be a problem.
 

wb292

I'm Awesome
Joined
Oct 29, 2019
Messages
244
Reaction score
248
Location
Arizona
You're the first one I've heard mention a 6.0 fan, I may have to give that a whirl. Also, I just put on a Bullhead City t-shirt as my mom lives there. Your timing is uncanny.
The 6.0 fan uses the same bolt pattern and hub dia as our clutches do. So it was a direct swap
 

AuroraGirl

I'm Awesome
Joined
Jul 27, 2020
Messages
1,164
Reaction score
1,386
Location
Northern Wisconsin
You must be registered for see images attach
You must be registered for see images attach

Ignore the fan clutch sitting under it on the first pic, that is just me seeing if it would fit my 1996 f150 (no not without opening up those bolt holes.. which i would rather not do,. im told the plastic vortec fans of the 4.3 and 5.7 with a lot of blades will work tho!)
 
Top