Engine getting hot towing

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Have any of you towed with the OE auxillary trans cooler setup and what were the engine/trans Temps?
 

wsteele

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Have any of you towed with the OE auxillary trans cooler setup and what were the engine/trans Temps?
I have and towed a 5000lb enclosed trailer a lot early on in my trucks life. The trailer was pretty low profile and pretty aero as big old trailers go, most of the towing was summer months. I rarely saw 230 degrees, even on hot days through mtn country with extremes being as high as 240 for short periods on pulls up into the Tehachapies in summer temps.

The thing is, I sometimes think my transmission temp gauge might have been off, as my tranny lasted about 76K miles and needed replacement. Reading the reports of what others have seen in the "Keeping coolant and transmission temps ..." thread, it really makes me wonder about that temp gauge.

Also, mine is a 4 speed and I was changing fluid and filters every 50K.
 
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1BADI5

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With my TruCool 40K my engine temps stay between 197-203* even when I'm out hoon'ing the hell out of it AND I have a stall converter.

What kind of spacing between the trans cool and condenser? What mounts are you using?

The highest trans temp I have had was 154* (Those readings came from the OEM and aftermarket gauge)
 

Geotrash

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With my TruCool 40K my engine temps stay between 197-203* even when I'm out hoon'ing the hell out of it AND I have a stall converter.

What kind of spacing between the trans cool and condenser? What mounts are you using?

The highest trans temp I have had was 154* (Those readings came from the OEM and aftermarket gauge)
But are you towing heavy with it? That’s the only circumstance where heat has been an issue with the 40k.
 
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Bonebad1

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With my TruCool 40K my engine temps stay between 197-203* even when I'm out hoon'ing the hell out of it AND I have a stall converter.

What kind of spacing between the trans cool and condenser? What mounts are you using?

The highest trans temp I have had was 154* (Those readings came from the OEM and aftermarket gauge)
I have it mounted in front where the aux cooler was. It only gets hot when towing
 
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Bonebad1

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I did tow this camper before the trucool. Trans temps were getting high, I think around 220-240. but the engine temps were good. Now after the trucool install trans temps havent gone above 175 but the engine temps are up. I am pretty sure the trucool is blocking too much airflow. I can try the water pump, flush, water wetter. but wont really know until I tow again which may not happen any more this year with school starting up
 

RedInCo

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I'll add my experience in response to gooffeguy. I have a 2010 Yukon Denali AWD (6.2L, 6 speed, short wheelbase, 140K, all stock with the factory maxtow package tranny cooler). I tow a 6900 pound travel trailer, often in Colorado. When not towing, engine temp stays at 210, tranny will get to 160-180. When towing on the flat, engine stays at 210, tranny is about 100 degrees above ambient. Add mild hills, the engine get to 220 or so on the climbs, tranny will go up to 215-225.

On big climbs, like I-70 at the continental divide, the engine will get up to 235, then quickly drop down to 210 when the fans kick on. This will repeat every few minutes. The tranny temp will climb steadily without regard for what the fans and the engine temp are doing. I aim to keep the tranny from getting above 250 for any length of time. If the tranny gets above 240 and I have a lot of climb to go, I chicken out and pull off and let it idle for a while.

Two weeks ago I camped for the night at Copper Mountain. Hitched up the trailer in the morning, jumped on I-70 going east. At the Silverthorne exit the tranny temp was 150. I cruised to the continental divide summit without stopping (doing about 45) and the tranny temp just hit 250 as I entered the tunnel.

I just bought a Tech 2. Does that allow me to turn the fans on high when underway? Would it be smart to have the copilot force the fans on during a big climb?
 

Geotrash

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I'll add my experience in response to gooffeguy. I have a 2010 Yukon Denali AWD (6.2L, 6 speed, short wheelbase, 140K, all stock with the factory maxtow package tranny cooler). I tow a 6900 pound travel trailer, often in Colorado. When not towing, engine temp stays at 210, tranny will get to 160-180. When towing on the flat, engine stays at 210, tranny is about 100 degrees above ambient. Add mild hills, the engine get to 220 or so on the climbs, tranny will go up to 215-225.

On big climbs, like I-70 at the continental divide, the engine will get up to 235, then quickly drop down to 210 when the fans kick on. This will repeat every few minutes. The tranny temp will climb steadily without regard for what the fans and the engine temp are doing. I aim to keep the tranny from getting above 250 for any length of time. If the tranny gets above 240 and I have a lot of climb to go, I chicken out and pull off and let it idle for a while.

Two weeks ago I camped for the night at Copper Mountain. Hitched up the trailer in the morning, jumped on I-70 going east. At the Silverthorne exit the tranny temp was 150. I cruised to the continental divide summit without stopping (doing about 45) and the tranny temp just hit 250 as I entered the tunnel.

I just bought a Tech 2. Does that allow me to turn the fans on high when underway? Would it be smart to have the copilot force the fans on during a big climb?
Great info. Thanks for the data points. No, I don’t believe the Tech2 will do that. And even if it could, it would be a huge pita and safety issue to try to do it while driving. You’d be better off having a tuner change the fan trigger points.
 

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