2004 Denali gets hot when parked

strutaeng said:

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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Hi ya sorry I do need to put periods in my posts my bad. So it has not overheated yet. It climbs just above 210 maybe to 220 not to much cause I always either shut it off or start driving again. I need to hook to my scanner and see it's temp next time exactly. Its when it starts to heat up at idle or parked the AC just turns hot. But once I start moving cold right away. Could it just be low on refrigerant?

strutaeng said:

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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Thank you. I will try that out tomorrow and see about the coolant flow. I do wish they would have kept a radiator fill cap.

Reefdude84 said:

Hi I have a 2004 Denali that when I am in drive threw or parked more then 10 min starts to get hot ac will start to blow warm air and the temp will start to go over 210 I have replaced radiator. Water pump and thermostat with housing also the fan clutch while driving all is great ac nice and cold and engine at normal temps idles great still as well.

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Don't know where u live but if south get rid of the thermostat. You really only need it if you live in cold (below zero) area. It serves to warm up the engine faster. Also be sure you hane correct mixture of antifreeze. Water only in not a goot heat disapater. Check timing chain or tensioner if a little loose when at idle it might be off a slight as not as much tension. I doubt your timing is off. I'm also sure when you changed all the water parts you flushed the engine. Make sure rad is full and flowing. Open cap when cold and run yhe engine you should see the liquid flowing.

NELLY1947 said:

Don't know where u live but if south get rid of the thermostat. You really only need it if you live in cold (below zero) area. It serves to warm up the engine faster. Also be sure you hane correct mixture of antifreeze. Water only in not a goot heat disapater. Check timing chain or tensioner if a little loose when at idle it might be off a slight as not as much tension. I doubt your timing is off. I'm also sure when you changed all the water parts you flushed the engine. Make sure rad is full and flowing. Open cap when cold and run yhe engine you should see the liquid flowing.

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Don't run it without a thermostat; these are modern engines. Geez.

First thought would be air in the cooling system, or a worn mechanical fan clutch.

If I read right, you haven't tested, or replaced the fan clutch?
You should be able to burp any air out of the cooling system by parking the front end on an incline (hood pointing up), and running it while squeezing upper and lower radiator hoses. If you have any air, that should both reveal it, and hopefully correct it.

Does it look like the fan is to far into the shroud? If it is on a fan clutch, it must be quite a ways in and not really sucking through the shroud opening. That would reduce the effectiveness I would think.

Reefdude84 said:

Hi I have a 2004 Denali that when I am in drive threw or parked more then 10 min starts to get hot ac will start to blow warm air and the temp will start to go over 210 I have replaced radiator. Water pump and thermostat with housing also the fan clutch while driving all is great ac nice and cold and engine at normal temps idles great still as well.

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You have a significant clue here; that the A/C *and* coolant temperature are both high. These systems are completely unrelated except in one place; Airflow through the grille.
You have a bad fan clutch, or a bad fan. What engine is it? My '04 just towed 8k from San Antonio to South Florida in temps as high as 105* with no issues. I have a new Hayden heavy duty fan clutch. My '94 truck with gas 5.7 had A/C issues- as I discovered they're famous for- until I installed a fan from a '05 Envoy 5.3. My '94 6.5 diesel also had weak A/C at low speed until I installed an early Duramax fan. GM's solution on the '94's was an accessory electric fan, but it was only special order, heavy duty, or extreme temperature regions. My '04 is the 8.1, so has a big fan; I don't know if the same fan is on the smaller motors. But at the end of the day, there is no state of engine tune that can affect your A/C performance, but in certain years and unlikely environments a bump in idle speed helps- which was built in to most stuff at least back into the '90s.

OH BTW- removing the polkadot grille cover reduced my transmission temperatures while moving by about 15*. They restrict airflow significantly.

The OP ghosted us and hasn't been here since June.

OP should remove the hot air intake he installed.