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Discussion Starter · #1 ·
Yes I have a 08 Silverado 2500 when pulling my 26’ toy hauler my duramax starts running towards 230 degrees . When I’m not pulling anything , normal driving conditions , 210 , normal or not?
 

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Discussion Starter · #3 ·
Yes I have a 08 Silverado 2500 when pulling my 26’ toy hauler my duramax starts running towards 230 degrees . When I’m not pulling anything , normal driving conditions , 210 , normal or not?
Engine temp I assuming. Gauge on my dash.
 

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That's a little warm especially for the upper Midwest. Have you cleaned your cooling stack lately?
 

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Discussion Starter · #5 ·
Engine temp I assuming. Gauge on my dash.
I’m sorry I’ve only had this truck for 3 yrs . I’m new to diesel trucks so what is cooling stack . When I first had warm running issues it was DPF filter and Catalytic so I went straight pipe and problem disappeared for a while and first time this year pulling it for a three hour trip it would warm up . Does it have anything to with using tow/haul mode?
 

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Discussion Starter · #6 ·
I’m sorry I’ve only had this truck for 3 yrs . I’m new to diesel trucks so what is cooling stack . When I first had warm running issues it was DPF filter and Catalytic so I went straight pipe and problem disappeared for a while and first time this year pulling it for a three hour trip it would warm up . Does it have anything to with using tow/haul mode?
I just found out what cooling stack was , radiator, trans cooler , I will clean those thoroughly as well as a radiator flush!
 

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Yes I have a 08 Silverado 2500 when pulling my 26’ toy hauler my duramax starts running towards 230 degrees . When I’m not pulling anything , normal driving conditions , 210 , normal or not?
Could be thermostats starting to go bad. My truck did this but it came with a check engine light. Was a pretty easy fix. Also consider a coolant flush. They are recommended every 150k miles
 

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Also the dash temp gauge can be somewhat inaccurate. You can buy a cheap OBD-II monitor (look up the one made by BAFX on Amazon) to read engine temp and some other stats more effectively.
 

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Yeah the dash gauge is actually a range. When your coolant temp is in roughly the 180-215 range, the dash will show straight up 210. But when it starts showing 220-230 range it's usually pretty well sync'd at that point so it does appear to be running a bit warm.

Like the previous poster said, if you start running a monitor to see the actual digital readings, you'll see how far off the dash gauge really is.
 

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I just found out what cooling stack was , radiator, trans cooler , I will clean those thoroughly as well as a radiator flush!
Have you physically looked between the radiator and the trans cooler for trash and removed it? The trucks are famous for gathering debris in this area and will drive up temps.

Secondly, have you checked to see if your fan clutch is operational? With the temps that you mention, you should hear the fan clutch engage to get the temps back into the normal range. If you temp remains at 230 and you continue to drive, that is dangerous for the drive train.

When I tow my 17k 5vr through the mountains in the summer months, the temps will rise to 220-230 when going up grades and when this occurs the fan clutch kicks in and returns everything back into the normal range very quickly.

Just some things to consider.
 

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Definitely some stuff to check here. But also if you're running a tune with additional HP, even with everything up to par where it should be, you could still have some heating issues when towing.
 

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Yes that is hot especially on a Duramax Not only flush and check the radiator, but also check the fan. Is it running as you go up the hill? You should hear that big fan roar when you go over 210. If not there's your problem. My transmission temp typically runs at 180 when mountain towing my 30' fifth wheel in the mountains. It does not go over 200 even in Texas towing. My engine temp floats around 210 to 215 towing in Texas. I would worry if it gets hotter.
 

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Do you have an aftermarket 'bumper grille insert'? GM keeps that area wide-open but many will add an insert for aesthetics and to cut-down on bugs and debris. If you're towing often, especially up elevation - or in excessive ambient temperatures - it's best to keep that area clear & open to maximize air flow.
 

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Another thing to consider is if the stack is packed full the hot air flow will be minimal and cannot activate the clutch fan. This happened to me, cleaned the stack - fan started cutting air again
 

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Yes I have a 08 Silverado 2500 when pulling my 26’ toy hauler my duramax starts running towards 230 degrees . When I’m not pulling anything , normal driving conditions , 210 , normal or not?
My '09 does exactly the same thing. I attribute it to the tune, and have gotten in the habit of keeping my rpm's up when hitting a hill. I pull a 36' 13,000lb fifth wheel.
 

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I will echo Johndago, keep the RPMs between 2000-2500 and don't try to go too fast up a grade.
My truck did NOT like just turning on the tow/haul mode and driving up the pass.
 

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Yes I have a 08 Silverado 2500 when pulling my 26’ toy hauler my duramax starts running towards 230 degrees . When I’m not pulling anything , normal driving conditions , 210 , normal or not?
More load more heat, not unexpected it will run a little hotter. If it is not in the red I dont think you have anything to worry about. Keep an eye on the trans temp, same thing, as long as it is not in the red not an issue. As someone also mentioned, factory gauges are not exactly accurate or linear, so do get stressed about actual readings just that it stays out of the red zone.
Good best practice when hauling heavy loads is to let the engine idle for a few minutes when you stop, there is often a rapid temp spike from residual heat after shutdown that can raise temps 30 degrees or more, if you let it idle it can reject the residual energy and reduce this.
 

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As a reminder, you should always have tow/haul mode engaged when hooked up to a trailer. Your transmission will thank you with a longer service life. Your brakes will last longer, too, since the transmission will downshift more aggressively to allow for engine braking.
 

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As a reminder, you should always have tow/haul mode engaged when hooked up to a trailer. Your transmission will thank you with a longer service life. Your brakes will last longer, too, since the transmission will downshift more aggressively to allow for engine braking.
WIth that much load, absolutely a good idea, as much for slowing down as anything.
 
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