2004 Denali gets hot when parked

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Reefdude84

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Here are some pictures of engine bay was busy yesterday so will get the list of parts together andIMG_20240623_122436222_HDR.jpgIMG_20240623_122455780_HDR.jpgIMG_20240623_122515244_HDR.jpg
 

strutaeng

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Remove the front clip and take a look at the front of the radiator. My 99 Silverado radiator was blocked solid on the lower portion front gunk and dust. I replaced it only to gain the wider radiator (had the narrow one).

Check to make sure you actually have coolant flow. Not sure how you would actually do that though on these because there's no radiator fill cap? Squeeze the large coolant top hose and it should have some resistance while engine is running. It should not feel too soft.

Check fan clutch. With engine hot, shut it off and check the fan blades. They should feel rigid and shouldn't spin freely.

Trying to convert to electric fans I think is kinda silly, because the problem may not be with airflow and possibly with coolant flow.

Edit: you can dunk your thermostat into an old pot of boiling water to make sure it's opening correctly.
 
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Marky Dissod

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Trying to convert to electric fans I think is kinda silly ...
The mech clutch fan's best feature is how much air it moves when the engine is at or over 2000RpM.
In other words, it's best suited for towing / hauling, where it makes perfect sense to sacrifice 2 or 3MpG to better protect the powertrain.

If you do not regularly tow / haul, electrical fans are better suited to '1500' daily driver activities.

I picked up 2MpG when I got rid of my mech clutch fan & installed electrical fans.
Best of all, AC performs so much better at idle than it did with the mech clutch fan.

For whatever it's worth, I got the WEAKEST electrical fan pair.
My understanding is that there are fan pairs that are strong enough to be usable with 2500 trucks.
 

strutaeng

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The mech clutch fan's best feature is how much air it moves when the engine is at or over 2000RpM.
In other words, it's best suited for towing / hauling, where it makes perfect sense to sacrifice 2 or 3MpG to better protect the powertrain.

If you do not regularly tow / haul, electrical fans are better suited to '1500' daily driver activities.

I picked up 2MpG when I got rid of my mech clutch fan & installed electrical fans.
Best of all, AC performs so much better at idle than it did with the mech clutch fan.

For whatever it's worth, I got the WEAKEST electrical fan pair.
My understanding is that there are fan pairs that are strong enough to be usable with 2500 trucks.
Yeah no, I completely agree with you. Also the electric fans do better at idle on the AC compared to electric fans based on my observations in my vehicles. But for towing, mechanical fans all the way. That's why the 2500s have stayed with mechanical fans (even the new 2500HD trucks still use mechanical fans AFAIK.)

I guess what I was trying to say is: let's steer the OP to fix his issue, because converting to electric fans has costs, involves tuning, takes time and can have complications in itself, and if he's got a coolant flow problem, it's not going to solve his problem. Let's focus on WHY it's overheating in the first place.
 
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strutaeng

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Reefdude84's coolant temp climbs and AC performance falters at idle.
He has not yet mentioned overheating.
I guess we interpreted his post differently (argh, I hate these posts with run-on sentences...not a freaking period!)

I assumed engine is overheating because he said it "starts going over 210", and he's changed the radiator (missed that on my previous post), thermostat and water pump... that's all an indication that engine is overheating in my perspective. AC running hot at idle is additional information and may or may not be related. Probably just low on refrigerant but could also be result of engine overheating at idle. IDK.
 

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