Engine getting hot towing

[Bonebad1]

2012 Yukon Denali xl Tow package. 150000 miles. Tranny flushed last month and diff and transfer case. Coolant 3 years old.
I tow a 5500lb camper with 800 lbs of passengers and plus all our stuff so probably around 7000 to 7500 lbs. We have a wdh all set up by the camper place we bought.our camper from. Last year the transmission would get warm, around 220 so I added a trucool 40k. Now the engine gets hot, around 230 when I turn the heater on to cool it off.
I am only going 50-60mph. What can I do to get the engine temps lower

 

[avalonandl]

Flush radiator, clean out the fins with a hose, check your water pump as LS water pumps lose their effectiveness often.

 

[wsteele]

2012 Yukon Denali xl Tow package. 150000 miles. Tranny flushed last month and diff and transfer case. Coolant 3 years old.
I tow a 5500lb camper with 800 lbs of passengers and plus all our stuff so probably around 7000 to 7500 lbs. We have a wdh all set up by the camper place we bought.our camper from. Last year the transmission would get warm, around 220 so I added a trucool 40k. Now the engine gets hot, around 230 when I turn the heater on to cool it off.
I am only going 50-60mph. What can I do to get the engine temps lower

There is a very informational thread started by @Geotrash on this very subject. I would give it a read. At a minimum, it will give you a good basis of understanding of the dynamics involved and alternatives.

Keeping coolant and transmission temps under control when towing in the summer heat

Hi All, the 2012 XL Denali is a towing beast, but after the cam upgrade, new HD torque converter, and adding the Tru-Cool 40K in front of the radiator, the engine itself is running warm now that we're getting into spring. Hauled our 6500 lb camper down to Virginia Beach this weekend in 83º...

www.tahoeyukonforum.com

 

[Foggy]

Your TrueCool is probably blocking some air flow to the radiator itself..
You may need to replace & upgrade your radiator.. Depending on how often you tow
and the weather conditions
Make sure you are towing and being smart about the transmission gear selection..
If you are only going about 55-60, then 4th gear would be the one you want...
5th and 6th are overdrive ratios and will tend to get the trans warm under heavy loads

You could also try the simple things like new coolant, water pump first..
For the summer, try a 30% dexcool/ 70% distilled water mixture with an additive
like water wetter coolant additive and see what happens

 

[swathdiver]

2012 Yukon Denali xl Tow package. 150000 miles. Tranny flushed last month and diff and transfer case. Coolant 3 years old.
I tow a 5500lb camper with 800 lbs of passengers and plus all our stuff so probably around 7000 to 7500 lbs. We have a wdh all set up by the camper place we bought.our camper from. Last year the transmission would get warm, around 220 so I added a trucool 40k. Now the engine gets hot, around 230 when I turn the heater on to cool it off.
I am only going 50-60mph. What can I do to get the engine temps lower

Make sure the mix of Dexcool to water is proper, if there's more dexcool than water its going to run at a higher temperature. 50/50 is what's called for, some do 60/40 for a little more cooling.

Transfer as much stuff to the trailer as possible.

Does yours also have the engine oil cooler?

 

[Bonebad1]

I'll have to check my dexcool ratio. I had it flushed a while back and haven't checked it since. It does have the oil cooler. Should I just change the water pump or is there a way to see if it is pumping good enough? .l

 

[Foggy]

I would change the water pump at that mileage/age.. Use a GM or ACdelco branded
pump if at all possible. And just replace all the dexcool coolant with 50/50 distilled water
or buy it premixed. Thermostat would be on my list as well while you are there...
I "think" my new GM pump that I bought last year from RockAuto came with a new
gm thermostat - much better build quality than the aftermarket parts store Tstats
and it's worth about $35 so you can justify the extra cost that way too

 

[Foggy]

For my application ACDELCO 251713 this is the part #.. Yours may be different. But this is
the one that has the thermostat already installed, so you get a new high quality Tstat too

 

[RED TAHOE LS]

180 degree thermostat....JMHO.

 

[Geotrash]

2012 Yukon Denali xl Tow package. 150000 miles. Tranny flushed last month and diff and transfer case. Coolant 3 years old.
I tow a 5500lb camper with 800 lbs of passengers and plus all our stuff so probably around 7000 to 7500 lbs. We have a wdh all set up by the camper place we bought.our camper from. Last year the transmission would get warm, around 220 so I added a trucool 40k. Now the engine gets hot, around 230 when I turn the heater on to cool it off.
I am only going 50-60mph. What can I do to get the engine temps lower

What you’re describing is normal coolant temp behavior when towing with the Trucool 40k. I’ve owned two of them on two different Yukon XL Denali’s and had the identical behavior to what you describe on both. I even upgraded to a cold case radiator on one and while it helped, it didn’t eliminate the problem. I wouldn’t waste time or money replacing water pumps or anything else. Just my opinion. The solution is to either relocate the tru cool to below the front bumper or mount a fan-forced one like the Derale below the bumper.

Also 220°F is well within the normal trans temp range on the 6L80E. You’re good to 265° with the Dexron VI fluid in these.