Engine Coolant Temp High Pulling Trailer

Spohner · July 17, 2018

Hey guys,

I have a 2017 Silverado LT with the 5.3 that I just bought a few weeks ago. Pulled our camper up I70 from Denver to Steamboat Spring in Colorado and had my truck getting warmer than I have ever had a truck get before. I was pulling about 2600-2800 pounds and was consistently getting temps around 220 - 230. This happened whether it was 90 degrees or 65 degrees out. Anyone else getting warm temps when pulling small loads?

Supreme Pizza · July 17, 2018

Seems a little warm. Did you check you engine, transmission, and coolant levels? Also, did you put the vehicle in "towing mode" (assuming you have that option). Are you running your A/C while towing? If so, shut it off.

Spohner · July 17, 2018

I did have it in trailer haul mode with the ac on and off throughout. Did not see that impact cooling though while driving. Fluid levels are all good. Just not sure as the truck only has 20,000 miles. I will take it to the dealer later this week. Just not sure if others have had similar issues in case I get the run around from the dealer.

txab · July 17, 2018

I believe you'll find this to be common to these trucks. Trans have thermostat that aren't going to let them go below about 190 anyway. Plenty have posted about this issue. Definitely warmer than I'd like.

GM wants these to run warmer

You can bypass the internal thermostat. Info is posted on this site

You can add a larger external cooler, but again without the thermo mod you''ll for sure be limited to 190

But 190 is fine

You have synthetic fluid in the trans which holds up better to the heat, but personally I'd like it lower

We've modded all our rigs to run cooler, and they stay about 180

Spohner · July 17, 2018

Anyone have the link to the internal bypass post?

BigBadSierra · July 17, 2018

GM will not honor the power train warranty if you mess with it or add a larger cooler.

So I just run it and will let them deal with it if it blows.

Supreme Pizza · July 17, 2018

35 minutes ago, BigBadSierra said:

GM will not honor the power train warranty if you mess with it or add a larger cooler.

So I just run it and will let them deal with it if it blows.

Yep. What he said.

mookdoc6 · July 17, 2018

Yup, GM wants these Ecotec's running warmer....just have to get used to it. They also Tick, make different noises too.....the one thing I noticed was changing the Trans fluid completely over to Mobil1 HP the trans consistently is 10-15 cooler now vs 2qty fluids of AC DELCO HP......You can try an AD PACK on cooler fluid....But just myself up Hills and 100f+ it now stays below 200f on coolant.

Grillo88 · May 21, 2019

On 7/16/2018 at 6:57 PM, Spohner said:

Hey guys,

I have a 2017 Silverado LT with the 5.3 that I just bought a few weeks ago. Pulled our camper up I70 from Denver to Steamboat Spring in Colorado and had my truck getting warmer than I have ever had a truck get before. I was pulling about 2600-2800 pounds and was consistently getting temps around 220 - 230. This happened whether it was 90 degrees or 65 degrees out. Anyone else getting warm temps when pulling small loads?

happened to me pulling our boat over Bethoud pass. Was nerve racking for sure

diyer2 · May 21, 2019

Just do more fluid changes is the way I'm rolling.

Grumpy Bear · May 22, 2019

On ‎7‎/‎16‎/‎2018 at 7:57 PM, Spohner said:

Hey guys,

I have a 2017 Silverado LT with the 5.3 that I just bought a few weeks ago. Pulled our camper up I70 from Denver to Steamboat Spring in Colorado and had my truck getting warmer than I have ever had a truck get before. I was pulling about 2600-2800 pounds and was consistently getting temps around 220 - 230. This happened whether it was 90 degrees or 65 degrees out. Anyone else getting warm temps when pulling small loads?

If I'm reading this right your talking about coolant temperature NOT transmission temperature? Two items if this is the case.

1.) Lower thermostat from the Camaro 195F instead of 207F

2.) Lower the antifreeze percentage. No less than 20% but lower than the factory fill 50%.

Lastly, get something like the Linear Logic Scan Gauge II or equivalent and read the water temperature directly from the ECM instead of that joke of a instrument GM provides.

If I missed the mark and you are actually speaking about the transmission ignore me.

Paintor · May 22, 2019

I watch Video’s of all these Camaro guys tweaking their motors and they will take a coolant thermostat and drill a hole in it. So if the thermostat sticks, the motor won’t overheat.

One guy had his thermostat spring bend sideways and seize in Florida...kept driving in traffic merely thru the coolant going thru the hole they drilled that kept the motor from overheating.

So I drilled a hole in the thermostat like they do. Something goes wrong I can swap it before the dealer sees it. Juz google it.

You will see lower temperatures towing. I did.

TheLawnGuy · April 11, 2021

I have a 2019 1500 LD that I bought with 20k miles on it and I pulled my 5x8 utility trailer with my zero turn on it all last year with no fluctuations in the engine temp gauge. About 2 months ago it started to rise to the line after 210 everytime I pull the trailer no matter how cool it was outside. It goes back down after about a minute or so but will rise back up and then go down again repeatedly until I'm idling at a stop light. Not sure if it's normal since it never rose above normal operating temperature anytime before this. It's still under warranty but running a lawncare business I can't really afford for it to sit at the dealership for an extended period of time. So going by most of the replies saying this behavior is normal, how come it never did it until about 2 months ago? Is it a warning sign of some sort for the thermostat going bad?