GM Transmission Temps

[RyanB]

Well, today was the day (yesterday now). Loaded everything up to use the Yukon to tow the LSV to Powell. 

Three people and four dogs, and all our gear for 5 days at the lake. Didn’t have much room in the Yukon, put a lot of stuff in the boat. 

Not was low 90’s when i left home. Temps i have seen before. 

Got on the highway and noticed the engine temperature was running a bit high right out of the gate. Took the first hill by Red Rocks, and it went way high. Couple miles up, and it got bad enough that I shut off the air conditioning. Engine cooled down a little. Inside temp warmed up a bunch.

Slowed down to about 30 MPH. Turned the air back on, and the engine temp went way up way fast. Before I knew it, there was a message on the dash warning about the temp and that the air was shut off.  On the plus side, the transmission temp never got about 200*  

Not a good way to start a 450 mile trip. So we turned around and headed home. Quickly emptied out that Yukon. I hooked the boat up to my truck, my wife took a dog and my nephew in the Jeep, and we left again. 

Set us back by about two hours. But we got here. 

When I had the auxiliary transmission cooler installed, I worried if the added size right in front of my radiator would create another problem. Well, it looks like I have my answer. 

I’m tired of chasing problems with the Yukon. When I get home I will step up my search for a replacement.

[asnowman]

5 hours ago, RyanB said:

Well, today was the day (yesterday now). Loaded everything up to use the Yukon to tow the LSV to Powell. 

Three people and four dogs, and all our gear for 5 days at the lake. Didn’t have much room in the Yukon, put a lot of stuff in the boat. 

Not was low 90’s when i left home. Temps i have seen before. 

Got on the highway and noticed the engine temperature was running a bit high right out of the gate. Took the first hill by Red Rocks, and it went way high. Couple miles up, and it got bad enough that I shut off the air conditioning. Engine cooled down a little. Inside temp warmed up a bunch.

Slowed down to about 30 MPH. Turned the air back on, and the engine temp went way up way fast. Before I knew it, there was a message on the dash warning about the temp and that the air was shut off.  On the plus side, the transmission temp never got about 200*  

Not a good way to start a 450 mile trip. So we turned around and headed home. Quickly emptied out that Yukon. I hooked the boat up to my truck, my wife took a dog and my nephew in the Jeep, and we left again. 

Set us back by about two hours. But we got here. 

When I had the auxiliary transmission cooler installed, I worried if the added size right in front of my radiator would create another problem. Well, it looks like I have my answer. 

I’m tired of chasing problems with the Yukon. When I get home I will step up my search for a replacement.

Oof. That is a crappy way to start a vacation.

[Nitrousbird]

 

 

 

 

16 hours ago, RyanB said:

When I had the auxiliary transmission cooler installed, I worried if the added size right in front of my radiator would create another problem. Well, it looks like I have my answer. 

I’m tired of chasing problems with the Yukon. When I get home I will step up my search for a replacement.

Odd.  I never experienced any of this with my Escalade EXT.  Truck weight was very similar to your setup.  AWD sucked a bit more power I'm sure.  I drove through the Kentucky/Tennessee mountains and didn't slow down a bit without any real rise in engine temp, but to be fair I was probably 2500lbs lighter in boat/gear combo then you.  Only time I even saw the needle move was WOT trying to accelerate up a long, steep hill...which also blew my AC compressor clutch two years in a row and was my incentive to buy something else.

[RyanB]

@Nitrousbird, I’d say there is a significant difference between the Tennessee “mountains” vs Colorado. Just in Denver, I’m down by 15% in HP (loss of 3% for every 1000’ elevation). I’d guess that I only got to 6500’ before I turned around. Between that, and the incline, the Yukon has never been able to maintain the speed limit here, usually tops out at 50-55 mph.  And honestly I wouldn’t expect it to. To be fair, other than higher transmission temps that most would like, the Yukon has worked well towing in the flats. Colorado mountains just seems to be its Achilles heel.  

I know every vehicle has limitations. I’ve always been one that thought most tow ratings were conservative (with my old 3500 I was several thousand pounds over its rating for its whole life). The 7800 pound rating on the Yukon, or at least my Yukon, proves to be optimistic. Hopefully whatever I end up with a replacement will work out better. 

[JeffK]

If the Armada had carplay or made it where you could put in an aftermarket stereo, I'd consider that one.  No idea what it would do at elevation, but they seem strong to me.  I am on calls all the time for work and am able to travel down and back to the lake during working hours if I plan ahead.  But carplay is a must for me.

[shawndoggy]

12 hours ago, RyanB said:

I know every vehicle has limitations. I’ve always been one that thought most tow ratings were conservative (with my old 3500 I was several thousand pounds over its rating for its whole life). The 7800 pound rating on the Yukon, or at least my Yukon, proves to be optimistic. Hopefully whatever I end up with a replacement will work out better. 

I mean I know you've already pretty much decided against the ford product, but in your use case scenario (long steep grades at oxygen deprived altitudes), forced induction has a substantial advantage ('cept at the pump with boat on the hitch of course.... eco or boost, but not both).  I guess you just need to decide if you want the SUV to be the tow rig or not.

As point of reference, highest trans temp I've ever seen on my F150 with tow package is 217, flogging it up a twisty 5000' climb in 110* heat (under 220 is said to be within normal operating range, thermostat for tranny fluid to circulate through cooler is apparently 195).  Mostly I see 203-210 on the interstate (even over the mountains).

Edited August 8, 2019 by shawndoggy

[ORMailbuboater]

On 8/7/2019 at 2:52 AM, RyanB said:

Well, today was the day (yesterday now). Loaded everything up to use the Yukon to tow the LSV to Powell. 

Three people and four dogs, and all our gear for 5 days at the lake. Didn’t have much room in the Yukon, put a lot of stuff in the boat. 

Not was low 90’s when i left home. Temps i have seen before. 

Got on the highway and noticed the engine temperature was running a bit high right out of the gate. Took the first hill by Red Rocks, and it went way high. Couple miles up, and it got bad enough that I shut off the air conditioning. Engine cooled down a little. Inside temp warmed up a bunch.

Slowed down to about 30 MPH. Turned the air back on, and the engine temp went way up way fast. Before I knew it, there was a message on the dash warning about the temp and that the air was shut off.  On the plus side, the transmission temp never got about 200*  

Not a good way to start a 450 mile trip. So we turned around and headed home. Quickly emptied out that Yukon. I hooked the boat up to my truck, my wife took a dog and my nephew in the Jeep, and we left again. 

Set us back by about two hours. But we got here. 

When I had the auxiliary transmission cooler installed, I worried if the added size right in front of my radiator would create another problem. Well, it looks like I have my answer. 

I’m tired of chasing problems with the Yukon. When I get home I will step up my search for a replacement.

I have 2016 Yukon XL Denali which comes factory with the HD trans cooler.  We drive from Portland to Northern Cali to Shasta Lake every year.  Fully loaded with a week of stuff and 5 passengers towing our 23 LSV over 8 mountain passes in southern Oregon the up over the 4311 feet Siskiyou summit.  I have never seen anything over ~200F tranny temp.  Engine temp never budged over normal operating temp in 90-100F outside temps.    2007 Denali would heat up on the tranny to 225F on the climbs but would come down on descent.   Engine temp was stable.  

Wonder if all is working correctly.  Sure you checked all this but just asking.  Is this a newer Yukon with variable electric fans?  Are they ramping up correctly?   Coolant concentration is correct?   Sorry to hear it let you down.   Would not expect that.  

Edited August 8, 2019 by ORMailbuboater

[dwc032]

We have an 08 Escalade with the 6.2 and it tows a 13 23LSV, all our gear and 5 people.  Tranny does get to about 240 in the mountains and temp gauge hovers between 1/2 and 3/4 when headed up Mnt. Hood In Oregon.  Temps come back to normal when on flat ground.  Like others have said, maybe the fans aren't working like there suppose to?  

[RyanB]

Appreciate the feedback. The Yukon has been traded in on a 2019 Expedition Max. Need to get 1000 miles on it before I can tow with it, but looking forward to something different (and hopefully with better performance). 

[JeffK]

37 minutes ago, RyanB said:

Appreciate the feedback. The Yukon has been traded in on a 2019 Expedition Max. Need to get 1000 miles on it before I can tow with it, but looking forward to something different (and hopefully with better performance). 

Would love to hear your feedback on it.  Nothing against fords at all, but they definitely run, sound, ride, start and feel different from a GM.  That's not at all  bad thing, but it is a hard thing to get used to if you have been a GM guy all your life.  I have always had Chevy's (read: able to get a supplier discount, not a fanboy thing), but did have a diesel excursion for a bit.  It just always felt off to me.  But it was a great product.  And the new fords are amazing.  I would really love to get back to an SUV, but haven't been able to find something I am excited about.  If they would just fix the air buffeting issue in the yukons, I'd go back to a newer denali, but it literally makes me nauseous to drive them with the current issues.

[RyanB]

5 hours ago, JeffK said:

Would love to hear your feedback on it.  Nothing against fords at all, but they definitely run, sound, ride, start and feel different from a GM.  That's not at all  bad thing, but it is a hard thing to get used to if you have been a GM guy all your life.  I have always had Chevy's (read: able to get a supplier discount, not a fanboy thing), but did have a diesel excursion for a bit.  It just always felt off to me.  But it was a great product.  And the new fords are amazing.  I would really love to get back to an SUV, but haven't been able to find something I am excited about.  If they would just fix the air buffeting issue in the yukons, I'd go back to a newer denali, but it literally makes me nauseous to drive them with the current issues.

I understand where you are coming from. I am very partial to MOPAR, and if they built a full-size SUV, that is likely where I would spend my money. But since they don’t I have to find a Plan B. 

I will say that my experience with my Yukon makes it much easier to switch from GM. But it still takes quite a bit to get used to the Ford. 

 

I know tons tons of people who are Ford brand loyal. Hopefully my experience with my Ex will make me lean that way, at least for full size SUVs for the future.