2010 Yukon Denali Overheating when 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.

petethepug

Michael
Joined
May 4, 2016
Posts
2,708
Reaction score
2,850
Location
SoCal
If your current radiator is over 10 yr old it would be wise to replace it with the surrounding hoses and heater hoses.

The radiators get clogged up with a really fine, powdery dust that accumulates like paint. After a while it restricts the thermal cooling effect when it needs it most. You can remove it and have it hot tanked but it’d be better to just replace it since you’re towing.
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
11,047
Reaction score
22,127
Location
Elev 5,280
In addition to the electric fans, should there/could there also be a clutch fan? The hub on the motor has threads for one, but it’s not there.

Do you mean the hub on the water pump?
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
11,047
Reaction score
22,127
Location
Elev 5,280
In a 2010 Yukon Denali?

Actually, this is nearly conclusive evidence that the engine had the water pump replaced at some point

I'm under the impression that the OE pumps still have the threads for the clutch fans. RockAuto shows GM water pumps with them for this year. Seems like I remember @iamdub dressing up his threads somehow.
 

intheburbs

Full Access Member
Joined
Aug 10, 2017
Posts
799
Reaction score
1,414
Location
SE MI
Mine is a '2500', 6.2L Denali. I'm due an oil change so I'll look for the block off plate. that sounds like a good option!!...
Edit: KC4, dangit, it's already there1 :(

2500 short wheelbase? Um, no.



In a 2010 Yukon Denali?

Actually, this is nearly conclusive evidence that the engine had the water pump replaced at some point

My 09 Sierra Denali has efans and a threaded water pump hub, and it rolled out of the factory like that.

I hit 235° when towing in the Rockies with my 8600-lb trailer. It doesn't bother me a bit. I let the factory cooling system do its thing.
 
Joined
Apr 11, 2018
Posts
6,767
Reaction score
13,388
Location
St. Louis
My 09 Sierra Denali has efans and a threaded water pump hub, and it rolled out of the factory like that.
Yeah, I posted a bit later that mine does too after going out and looking at it, lol

For some reason I kept picturing in my head that it didn't, and the hub only stuck out of the pulley a tiny bit. That's actually on the 2002 Mustang 4.6. I have too many vehicles here, I'm starting to confuse their parts, lol

Kind of like kids names as you get older
 

Foggy

Full Access Member
Joined
Jul 25, 2019
Posts
1,031
Reaction score
1,293
Location
KS
My true GM replacement pump on mine from a few years ago has threads on
the hub as well. I just left the plastic protector piece on it so I won't cut
myself on it.
The E fan strategies on these gen 4 gm900's kinda suck in my opinion.
I'm sure it has to do with cafe or epa crap.
At highway speeds the fans won't come on at all. Thats why when you slow
down towing to about 45-50 the engine cools off.
I've reset my override temp to see if I can get it to trigger the fans to ON
but haven't towed hard in the heat yet to test it out.
My advice to an owner of a 14 year old tow vehicle is to at least get
a new OE radiator (as they catch lots of unseen crap as mentioned) or upgrade
to an all aluminum aftermarket one if towing heavy lots
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
1,538
Reaction score
2,081
Location
(718)-
The E fan strategies on these gen 4 gm900's kinda suck in my opinion. I'm sure it has to do with CAFE MpG or EPA crap.
Yep. Motor oil, ATF, & gear oil all have a bit less friction @ 221F than they do @ 203F.
GM would rather you get 1 or 2 more MpG, than your under the hood stuff last longer.
At highway speeds the fans won't come on at all.
That's why when you slow down towing to about 45-50MpH the engine cools off.
Somewhere between 45MpH & 50MpH, the fans can no longer outperform
the passive headwind of forward motion shoving air through the radiator.
So it becomes pointless to waste energy.
(I forget at which road speed having the fans 'on' actually hinders airflow ...)
 
Top