Summer heating Issues!!

ajmalian · May 31, 2018

Hey guys....

I've got a '16 Denali with a supercharged 6.2L engine and 8-speed tranny. It was a standard 2.9L Whipple set-up and I've had this set-up for about 2 years now. Last year everything was fine. Typical of Dubai summer, we had even seen highs of 125 to 127 degrees and the truck did perfectly fine.

This year, we've seen highs of 105 degrees as of yet, however I have seen my temp gauge going up while it was only 94 degrees outside.

I don't understand. up to 60mph, it maintains the normal temps of 210 degrees, however should I accelerate beyond, and I mean conservative acceleration, nothing aggressive from say 60-75 or even 80mph, the needle starts moving up and it goes all the way up to around 3/4 to the overheating mark, say about 230-240 degrees.

Any body have any idea what this could be and what could my solution be?

I've checked, I have no leaks and even my thermostat seems to be working fine.

Perhaps a bigger radiator? What do you all think I should do?

I look forward to your positive feedback.

Best regards.

Crstfr · May 31, 2018

man i have no idea.. but damn.. 125-127... holy cow!!!... ..would never leave the house! lol

adamj2121 · May 31, 2018

Do you have the active grille shutters? If you do it could be that the truck is closing them for aerodynamics once you are above 60 and isn't registering that it is getting hot enough to open them back up. That would be my first thought since it seems to weirdly only happen above 60.

wforrest08 · May 31, 2018

127 Celsius? Hot Damn no wonder that Chevy don’t wanna work...

Not sure how much rural desert driving you do but I’d start by blowing out the radiator and AC condenser and space between them with compressed air. We run a lot of quads and side by sides a lot of miles in dusty conditions (both dirt and sand) and once you start getting the fins packed they get HOT quick.

Check the air dam and area around it for damage or if you have removed part/all of it reinstall it and go for a drive GM claims even at highway speeds it pushes air though the radiator. The Avalanches even had a disclaimer in the owners manual about this. I’d say 90% of us here don’t see the average air temps your seeing so we might get by with it removed were you might not.

Check that both radiator fans run when it’s at temp with the AC on (does it get hot enuff there for you to even run the AC?)

DCazares · May 31, 2018

2 hours ago, adamj2121 said:

Do you have the active grille shutters? If you do it could be that the truck is closing them for aerodynamics once you are above 60 and isn't registering that it is getting hot enough to open them back up. That would be my first thought since it seems to weirdly only happen above 60.

^This. I think it's the active shutters as well.

hizzo3 · May 31, 2018

Might also be a partially stuck thermostat. I'm sure you're generating quite a bit of heat keeping it at that speed. these trucks while pretty, have the aerodynamics of a brick.

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seamus2154 · June 1, 2018

I cannot believe what comes out of my radiator, condensor, and intercooler fins every year when cleaning and blowing them out on all my cars. My Zo6 was running 10 degrees hotter. Put it on the lift and started with compressed air on a wand stick. There was a pile of crap on the floor. Then back flushed the condensor and radiator. Big difference when summer comes. That is where i would start, as it is probable in your environment, as it is here in south Florida.

ajmalian · June 2, 2018

On 5/31/2018 at 9:39 PM, adamj2121 said:

Do you have the active grille shutters? If you do it could be that the truck is closing them for aerodynamics once you are above 60 and isn't registering that it is getting hot enough to open them back up. That would be my first thought since it seems to weirdly only happen above 60.

Hey there....no I’m afraid not. The 2016’s, at least here in Dubai never came with the grill shutters.

ajmalian · June 2, 2018

On 5/31/2018 at 11:51 PM, wforrest08 said:

127 Celsius? Hot Damn no wonder that Chevy don’t wanna work...

Not sure how much rural desert driving you do but I’d start by blowing out the radiator and AC condenser and space between them with compressed air. We run a lot of quads and side by sides a lot of miles in dusty conditions (both dirt and sand) and once you start getting the fins packed they get HOT quick.

Check the air dam and area around it for damage or if you have removed part/all of it reinstall it and go for a drive GM claims even at highway speeds it pushes air though the radiator. The Avalanches even had a disclaimer in the owners manual about this. I’d say 90% of us here don’t see the average air temps your seeing so we might get by with it removed were you might not.

Check that both radiator fans run when it’s at temp with the AC on (does it get hot enuff there for you to even run the AC?)

Ok thats a lot of technical points there. To answer your questions/suggestions and proposals;

1. Not sure on this, however I will be taking my truck to the speed shop soon to attend to the entire matter.

2. I’ve removed my air dam since 6 months or more because I, during winter, would go off roading and hence needed the ground clearance. However, what did change in the last week is that I got a 2.5” leveling kit...could that have possibly caused this? As in the combination of no air dam and a 2.5” lift at the nose, exposing more summer air to the radiator something?

3. I’m quite confident that both fans are running....over time if anything...especially once the engine hits operating temps of 210 degrees FAHRENHEIT ;-P

And yes given the choice we wouldn’t leave home either...

ajmalian · June 2, 2018

On 5/31/2018 at 11:55 PM, DCazares said:

^This. I think it's the active shutters as well.

Like I mentioned above, I don’t have active shutters.

ajmalian · June 2, 2018

On 6/1/2018 at 12:11 AM, hizzo3 said:

Might also be a partially stuck thermostat. I'm sure you're generating quite a bit of heat keeping it at that speed. these trucks while pretty, have the aerodynamics of a brick.

Sent from my XT1585 using Tapatalk

I had upgraded my thermostat not too long after My truck got supercharged, because during the installation of the supercharger, for some weird odd reason there was this huge shortage in the market on the availability of thermostats. I’ve had these upgraded thermostats before in my naturally aspirated 2011 Sierra and I could see a huge difference in temps, however when I installed it on this truck when supercharged...it did not seem to make almost any difference. The coolant temp needle bearly came below the 210 mark. I’m assuming the thermostat possibly too isn’t doing its job. Gotta check that too.

ajmalian · June 2, 2018

On 6/1/2018 at 5:47 AM, seamus2154 said:

I cannot believe what comes out of my radiator, condensor, and intercooler fins every year when cleaning and blowing them out on all my cars. My Zo6 was running 10 degrees hotter. Put it on the lift and started with compressed air on a wand stick. There was a pile of crap on the floor. Then back flushed the condensor and radiator. Big difference when summer comes. That is where i would start, as it is probable in your environment, as it is here in south Florida.

Thanks buddy. Will check and let you know. Didn’t think about the radiator or condensor being blocked. I mean I can see the radiator and it seems clean. Gotta check out the condensor.

ajmalian · June 2, 2018

Will update everyone here once I figure out what went wrong.

seamus2154 · June 2, 2018

3 hours ago, ajmalian said:

Thanks buddy. Will check and let you know. Didn’t think about the radiator or condensor being blocked. I mean I can see the radiator and it seems clean. Gotta check out the condensor.

Mine didn't look dirty either. It was a suggested maintenance from a friend who races. Those fins are pretty narrow but collectively held ALOT of debris which reduced cooling. Remember blow from the engine compartment out as it is jammed in from the front. Then follow with a stong hose and water. You will be amazed what comes out. Good luck