Cooling System Towing Test Results, Before/After Mods

[Silverado LT]

So I wanted to give an end of the year update to this thread.

 

I went all summer without any issues while towing this summer.  We had several short (<50 miles) tows and several longer (65, 90, 100) mile tows.  The V6 gets a workout but has been getting the job done.  I always fill up with E85 before a tow to maximum power and cooling.

 

But I ran into trouble this weekend with the last tow of the year.  80 mile trip one way, 70mph, 15-20mph sustained winds.  On the trip home, I would hear an audible noise from my transmission on almost every downshift.  The sounds was more clunky and less grindy.  Trans fluid temps ranged between 190 and 198.  The frequency of the noise has me concerned.  From some of the other research I have done, it sounds like the noise might be coming from the torque converter.  I'm not sure what to do next.  

 

I love the truck but I'm not sure if I'm asking too much of it.  Fully loaded for my use, I know I'm under the towing capacity of 7100# and GCWR of 12800# but not by much.  At the lightest I tow I'm probably 1,000# under each but at the heaviest I'm probably only 300-500# under those ratings.  

 

The other thing I'm not real thrilled about is the passenger rated tires that came on the truck.  They are great for fuel economy but the side walls are way too soft. I've already broke the seal on the bead on two of the tires doing light off roading.  With the additional cooling mods I should do and the purchase of new tires, I'm considering replacing the truck.  

 

[Jim Lynch]

I’m really enjoying this thread. I’ve decided on a 187 Stant superstat and grabbing a diablo tuner for the fan change. . One thing I think I saw somewhere was the use of a larger radiator. Is there one available or worth doing??I have a 1500 4x4  lt trailer package and was wondering if the 2500 model radiator would fit and help. Reason I’m asking is I think I’m seeing a small leak below the drivers side tank. Stay with stock or upgrade? Where is the radiator model stamp located? Appreciate the feedback.

[JimCost2014]

31 minutes ago, Jim Lynch said:

I’m really enjoying this thread. I’ve decided on a 187 Stant superstat and grabbing a diablo tuner for the fan change. . One thing I think I saw somewhere was the use of a larger radiator. Is there one available or worth doing??I have a 1500 4x4  lt trailer package and was wondering if the 2500 model radiator would fit and help. Reason I’m asking is I think I’m seeing a small leak below the drivers side tank. Stay with stock or upgrade? Where is the radiator model stamp located? Appreciate the feedback.

Welcome to the site.

 

What year of truck? Radiator might be covered under warranty.

They had thermostat's that were creating too much pressure on the early years resulting in cracks, which became leaks.

 

When I was selling Chevy trucks, my rule of thumb, was if possible, have more truck than you need to tow, takes a lot of the guessing game out of it.

[flyingfool]

i wonder if the duramax diesel radiator would fit?

[Jim Lynch]

Ah, it’s out. It’s a 2013, pretty much on my own. The trailer is  about 3500# SA. Not too bad. Just a maintenance thing right now. Hate to drain it twice if the radiator is bad. I’ll check this am . Clean it up and run it. See if it stays wet. Antifreeze should stick around if it’s the case. It’s the dexcool. 

[Eddie 70]

16 hours ago, Jim Lynch said:

Ah, it’s out. It’s a 2013, pretty much on my own. The trailer is  about 3500# SA. Not too bad. Just a maintenance thing right now. Hate to drain it twice if the radiator is bad. I’ll check this am . Clean it up and run it. See if it stays wet. Antifreeze should stick around if it’s the case. It’s the dexcool. 

You can rent a tool at Autozone and pressurize the coolant system and see the leak pretty quickly. I built one and have had it for about 10 years and found two leaks over the years.

[flyingfool]

On 11/9/2019 at 8:26 PM, Jim Lynch said:

I’m really enjoying this thread. I’ve decided on a 187 Stant superstat and grabbing a diablo tuner for the fan change. . One thing I think I saw somewhere was the use of a larger radiator. Is there one available or worth doing??I have a 1500 4x4  lt trailer package and was wondering if the 2500 model radiator would fit and help. Reason I’m asking is I think I’m seeing a small leak below the drivers side tank. Stay with stock or upgrade? Where is the radiator model stamp located? Appreciate the feedback.

yup, not sure if there are any other misc. parts to make this install into the 5.3 1500 trucks

https://www.gmpartsonline.net/oem-parts/gm-radiator-23172440?c=Zz1jb29saW5nLXN5c3RlbSZzPXJhZGlhdG9yLWFuZC1jb21wb25lbnRzJmw9MSZuPVNlYXJjaCBSZXN1bHRzJmE9Y2hldnJvbGV0Jm89c2lsdmVyYWRvLTI1MDAtaGQmeT0yMDE2JnQ9aGlnaC1jb3VudHJ5JmU9Ni02bC12OC1kaWVzZWw%3D

[jsumner83]

I have a 2017 sierra with a 5.3, and like others, my engine starts running hotter while towing uphill. 
 

can I just purchase the camaro thermo and not change the tune on the fans, or do I also need to make that change? I am unsure of how to change the fan settings. 
 

please let me know if/how and also if even required if I purchase the 194 degree thermostat. 
 

[14burrito]

On 1/5/2023 at 3:55 PM, jsumner83 said:

I have a 2017 sierra with a 5.3, and like others, my engine starts running hotter while towing uphill. 
 

can I just purchase the camaro thermo and not change the tune on the fans, or do I also need to make that change? I am unsure of how to change the fan settings. 
 

please let me know if/how and also if even required if I purchase the 194 degree thermostat. 
 

194 vs the 20X crack temp isn't huge IMO without the airflow (full open I'm not sure what the camero one runs with the 5.3 tahoe ones about 232 iirc).

 

You can alter fan speed with a diablo intune i3