Cooling System Upgrade

[Giggity231]

Hello fellow GM owners

 

I have a 17 Silverado 1500 with a 5.3 and 3.42 gears. I tow a camp trailer that's 5100 lbs dry (probably around 6100 with water & camp gear). I'm within the weight limit of the truck, but I usually camp at 8000-9500 ft, so I pull it up some nasty steep long roads. I've been pretty disappointed with the cooling system on the truck. Granted I'm pushing it pretty hard...but my old man's 1997 Sierra 1500 does a better job keeping cool then mine. When going up a steep road it's not uncommon for my tranny to hit 240+ (even hit 260 once) and engine hits 235. It will rebound pretty quick once we plateau. My truck isn't max tow but it does have the radiator with built in oil and tranny cooler. I plan on keeping this long term so wanting to keep things closer to normal operating temps.

 

Have any of you done a cooling system upgrade? I was thinking of a Mitsumoto Rad (link below). But not finding much info on them online. Plus their BBB rating isn't that great...they say they don't handle vibrations well and I'm driving on a lot of washboard dirt roads. 

 

Performance Aluminum Radiator, fits Chevrolet Silverado 1500 V8 2014–2018 (mishimoto.com)

 

And advice appreciated. I went back to October and couldn't find this topic mentioned.

[CamGTP]

The transmission can be a simple fix. You can do the "pill flip" in the transmission thermostat so it's always open or there is a revised thermostat out that opens at 150 something degrees instead of the factory 190ish. Both would help lower transmission fluid temps.

 

Your coolant temps are on par with a stock thermostat too. The truck will run at 210-214 unloaded and adding 20 degrees is normal. On long full throttle pulls in my truck I will hit 230 on the regular. They sell a lower temp thermostat for these trucks, that would be far cheaper than a whole new radiator.

[Giggity231]

1 hour ago, CamGTP said:

The transmission can be a simple fix. You can do the "pill flip" in the transmission thermostat so it's always open or there is a revised thermostat out that opens at 150 something degrees instead of the factory 190ish. Both would help lower transmission fluid temps.

 

Your coolant temps are on par with a stock thermostat too. The truck will run at 210-214 unloaded and adding 20 degrees is normal. On long full throttle pulls in my truck I will hit 230 on the regular. They sell a lower temp thermostat for these trucks, that would be far cheaper than a whole new radiator.

Thanks for the info. I'll look into the lower trans thermostat. Way cheaper and easier then that new Rad.

 

Good to know on coolant temps. Never had a vehicle that did that. 

[dieselfan1]

Pulling a similar weight Trailer with my old stock 2018 , I would experience coolant temps 210 on flat roads but on the grades out west it would do the same , up to 235-240 ish then cool right back down to 210 at the the top. 235-240 isnt going to hurt it one bit as long as you have plenty of airflow. This is considered normal in my book.

Like Cam said , flip the pill for a cooler tranny. I flipped it on my lifted Chevy and it's most effective.

[newdude]

Pill flip, new GM lower temp thermostat or the SureCool trans thermostat delete.  Stock cooler works quite well once you do one of these 3 mods.  Also, I'd change as much of the ATF out as possible since its already seen those high temps.  

 

Thermal Bypass Valve Installation – TechLink (gm-techlink.com)

 

Must Have - Superior 6L80 6L90 SURE-COOL Cooler System - Easy-to-Install (globaltransmissionparts.com)

 

I would skip on the radiator if your engine coolant temps are ok.  235 is toasty, but still below the shutdown limit.  The trans cooler on 2017 doesn't even go through the radiator, its direct from the transmission to the cooler and back.  

 

Edited February 21, 2022 by newdude

[Grumpy Bear]

Steep mountain grades towing. This service is WAY below the air speed need of the cooling system. newdude will ( I hope)correct me if I error here but the fan tip in point is about 215 F I believe. Now I'm first on the bus to installing lower cooling thermostats and flipping pills but you could run without a thermostat and over heat when road speed is low and the fans don't start to come on until 215 F. Here's a graph I generated off my truck a few years ago. Forget the actual temperatures, fluid and air I logged. I run a cold water stat and a flipped pill. It's also V6 but the air speed to temperature trace is the same for all fin fan exchangers and a radiator is a fin fan exchanger. Run slower than 50 or higher than 57 mph and you are off the peak cooling capacity of the system. 

 

 

Cameron I think can confirm the the fans can be set lower. 192 F I think. The lower Katech 174 F thermostat will help as well the pill flip WHEN the road speed is high enough to create best exchange. 

 

At such slow speeds it may take a remote ATF cooler with thermostatic tripped fan to get it under control assuming you believe 180F or lower in under control. 

 

2 cents worth

[CajunFries]

Idk where you live but I’m in SoCal and in the summer time, IT GETS HOT. Plus I’m boosted and got a heavy foot. So here is my suggestion:

*Mishimoto radiator
*Katech 174* thermostat. 
*truCool 40k trans cooler (run it inline AFTER the radiator’s trans cooler)

*flip the factory gut of the trans Tstat. (Look it up on YT, takes like 5 mins with 1 hand

 

Im running a 160* Tstat. Around town with ambient temp between 70-80 the coolant stays around 185-195. Trans ALWAY stays cool around 120* driving around normally not towing. Towing 5k up and over the hills on a 95* day the trans never got hotter than 170. 

 

just my 0.02.

[YYC-SIERRA]

When you mount a large aux cooler directly in front of your factory radiator, are there any issues with reduced cooling to the factory rad? 

[Giggity231]

This got several replies that I missed. I guess being OP I assumed I'd get a notification. Still learning this website. 

 

Thank you all for the info. I'll get the tranny thermostat fixed and see how it does pulling for the summer. If I can avoid spending $900 on a new rad I'll happily do so!

[Grumpy Bear]

1 hour ago, Giggity231 said:

This got several replies that I missed. I guess being OP I assumed I'd get a notification. Still learning this website. 

 

Thank you all for the info. I'll get the tranny thermostat fixed and see how it does pulling for the summer. If I can avoid spending $900 on a new rad I'll happily do so!

 

If you follow your own post you will get notifications. 

[pokismoki]

i think the Mushimoto rad is a bit over priced, not sure but the 6.2 rad is much larger than stock 5.3, and probably cost $350 vs $900 for mushimojo

[mikeyk101]

6 hours ago, pokismoki said:

i think the Mushimoto rad is a bit over priced, not sure but the 6.2 rad is much larger than stock 5.3, and probably cost $350 vs $900 for mushimojo

Is the 6.2 a direct replacement or is different mounting hardware needed?

[pokismoki]

i havent done the conversion , as my stock unit still maintains ok temps in my climate,   i noticed durring dyno runs the 5.3 got hot hot very fast with just 2 pulls, so power adders and hot climate along with towing would make it a good upgrade, when it comes time to change out the coolant

[Grumpy Bear]

6 hours ago, pokismoki said:

i think the Mushimoto rad is a bit over priced, not sure but the 6.2 rad is much larger than stock 5.3, and probably cost $350 vs $900 for mushimojo

 

Same radiator but there are two. NHT is a bit thicker. 

[Giggity231]

15 hours ago, Grumpy Bear said:

 

Same radiator but there are two. NHT is a bit thicker. 

Maybe a dumb question but what's NHT? The 6.2 rad?