it depends on the vehicle. some with good air flow it over rides it pretty soon. they have rubber flaps that you can put in the fan shroud they will close with vacuum and open when airflow from mph overcomes the vac from the fan.
2010 Yukon Denali Overheating when Towing
- Thread starter Tim907356
- Start date
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.
This is exactly why I put a manually controlled Efan on my derale trans cooler.
When towing at hwy speeds, the engine fans don't come on but my trans temps
continued to climb. Now I can just flip my toggle switch to bring fresh air thru
the derale trans cooler independent of air incoming to the radiator. It usually drops
my trans temps 10-15* within 1-2 miles. My coolant rarely gets hot due to mu\y
187* thermostat and mishimoto radiator. And removing the factory HD aux cooler
in front of everything has helped my coolant and even my ac perform better without
that extra heat and blockage. I do run a a big ass aluminum pan that holds about
3 extra quarts of fluid too !!
When towing at hwy speeds, the engine fans don't come on but my trans temps
continued to climb. Now I can just flip my toggle switch to bring fresh air thru
the derale trans cooler independent of air incoming to the radiator. It usually drops
my trans temps 10-15* within 1-2 miles. My coolant rarely gets hot due to mu\y
187* thermostat and mishimoto radiator. And removing the factory HD aux cooler
in front of everything has helped my coolant and even my ac perform better without
that extra heat and blockage. I do run a a big ass aluminum pan that holds about
3 extra quarts of fluid too !!
I have a whole thread on this here, in case it's helpful: https://www.tahoeyukonforum.com/thr...towing-in-the-summer-heat.125753/post-1562470
Long story short though, as others have said, what you're experiencing is pretty close to normal when towing heavy in the summer with a Denali. That said, the radiators in these seem to get less and less effective over time. For best results, I would replace yours with a new one that has the 1.25" thick core. I ran a Cold Case for a while but like they all do, it started leaking, so I installed a Denso OEM-style with the 1.25" core. I also installed new cooling fans for the K5L enhanced cooling package. So far, so good towing 7500 lbs this summer.
One thing to check is the condition of the baffles that are on either side of the radiator. They're there to direct cooling air into/through the radiator instead of having it bypass and go directly into the engine compartment. I'm not sure how much they help with electric fans but make sure they're in good condition.
Good call.
Update: it was a hot day today as we pulled our 7500 pound camper over the spine of the Appalachian through West Virginia. No problem keeping the engine and transmission cool with our current set up and replacement radiator. Coolant temperature gauge got up to the three-quarter mark a couple of times, but quickly cooled back down. Transmission maxed out at 217°F.
tagexpcom
Full Access Member
- Joined
- Aug 12, 2023
- Posts
- 173
- Reaction score
- 144
Last Aug, we bought a 2021 Yukon Denali 6.2L but did not have the towing package (e.g. does not have tow cooling). As part of the pre-purchase, we test pulled our 5300lb 7 x 14 dual axle trailer up a 10mile, 6% grade over Mt Ashland with 107F ambient! and it performed A-OK. The trans reached 200F. The engine steady at 210F (normal). Yawn...! Since then, we've towed 5,000+ miles over several 10 mile mountain passes and no issues - e.g. 185F max trans and steady engine 210F with ambient temps <90F.
Don't know about 2010 but I'm guessing it's a very capable rig and that overheating would be due to worn parts or systems and could be restored.
Don't know about 2010 but I'm guessing it's a very capable rig and that overheating would be due to worn parts or systems and could be restored.
Last edited:
OP
OP
Tim907356
Member
- Joined
- Jan 17, 2020
- Posts
- 64
- Reaction score
- 41
Great comments and rec’s from everyone.
I found a 4-row all aluminum 2-3/8” wide aftermarket radiator that looks really attractive. With all hoses, thermostat and other bits replaced, wouldn’t this be the best cooling option?
I found a 4-row all aluminum 2-3/8” wide aftermarket radiator that looks really attractive. With all hoses, thermostat and other bits replaced, wouldn’t this be the best cooling option?
petethepug
Michael
If it fits, yes, do it. You’ll always do wells with a new radiator, especially a more efficient one. Keep in mind new vehicle are spec’d out for towing based on all new, 100% effective and efficient components, all working together.
When the coolant degrades, sediment builds up internally, the motor needs a tune, trans fluid isn’t so fresh, potentially poor gas leads to carbon buildup and detonation… the extra thermal capacity of that HD radiator is your safety buffer.
A Denali really needs a larger radiator for towing anyway. The twin a/c units on a hot will really heat up the a/c condenser something fierce. Less load on the a/c means less power from the alternator & motor and cooler cabin temps.
When the coolant degrades, sediment builds up internally, the motor needs a tune, trans fluid isn’t so fresh, potentially poor gas leads to carbon buildup and detonation… the extra thermal capacity of that HD radiator is your safety buffer.
A Denali really needs a larger radiator for towing anyway. The twin a/c units on a hot will really heat up the a/c condenser something fierce. Less load on the a/c means less power from the alternator & motor and cooler cabin temps.
that brand is the radiator? I wanna say it's cold case that doesn't seem to have a good rep on here. they leak at the welds after a few years.
More rows after 2 do not increase cooling capacity, surprisingly. I tow at the max with my 2012 over the mountains all summer long in the heat, with a modified 6.2L. I had a Cold Case in it for 3 years, but like all of them, it sprung a leak this spring. I replaced it with a new Denso (OEM) with the 1.25" core and it's doing great this summer. You really can't beat the OEM cooling system design on these.
