04 Sierra Engine Cooling Assistance

[sefiroxx]

Temps hit 100+ here and the idle heating problem is back. Time to solve it permanently.

 

04 with 4.8 and engine driven mechanical fan. Water pump, thermostat, fan clutch have been replaced in the past few years.

 

Normal driving, temps hover just bellow 210 (~202). Normal stop and idle, temp remains fine. But a long idle in the sun (>30) will lead to temps climbing to 235. Some increase over idle or ac off will hold it in check. Get back to driving with air flow will drop the temp within a couple minutes. If I drive a long time, it'll go back to the 30 minute delay before climbing under idle. If I drive just an coupe of minutes, the temps will climb within a few minutes under idle. So, drive around air flow takes a while to cool not only the radiator but also the engine block.

 

So, figure I have two options.

a) add an auxiliary pusher fan on the front of the radiator that is either / both auto our manual controlled

b) pull the mechanical fan, clutch, shroud and add a dual puller fan with auto/manual control. On this option, based on my experience with my Cadillacs, it would be nice if the fans come on in low whenever the ac is turned on and adjust to high when the temps climb.

 

Any recommendations, experiences, suggestions, brands to stay away from? Looking for info on hooking directly to coolant sensor, shroud impact, fitment etc.

[rjgti]

how plugged is your rad, inside and out

[rjgti]

for the ouside I use ac coil cleaner.  need to pull upper fan shroud.  depending on how dirty it is you may need a couple of cans of it

[txab]

As suggested above, check radiator fins and condenser fins for blockages. Check for bent fins. Also make sure air that goes in the front is not bypassing or going around the radiator. There are some filler panels at the ends If you have a trans cooler mounted directly in front of condenser/radiator, that will increase the heat load going through the radiator.

 

I don't experience your issues here in Tx. My idle is slightly higher though due to my tune. iirc around 600 rpm or so. Sitting still for extended periods of time in high heat, my trans temps do get a bit higher than normal. I run an auxiliary cooler. Normally temp is only 40-50 degrees above ambient, parked it gets a tad higher

[sefiroxx]

how plugged is your rad, inside and out

It's clear, replaced 4 years ago.

 

[rjgti]

take some laser temp readings on input rad hose and output rad hose, state your temp drop

[sefiroxx]

Have the gun with me. Problem only occurs once in a blue moon.

[rjgti]

that makes it tough.  keep us posted

[CapitalTruck]

Was it an OEM replacement radiator and fan clutch?  I’m telling you, all aftermarket stuff is questionable.  I have been dogged numerous times in recent months from power steering lines on my truck to anti-rattle clips on the brakes of my mom’s Highlander.  Never assume a replacement part is good, especially if it’s aftermarket.  My number one suspect would be that fan clutch.  Make sure all the shrouds there.  I had to look at another truck once to make sure mine were put in right.  Make sure also your replacement radiator was the correct one for your engine.  I have faith in Modine and OEM.  Don’t know about others.

Edited July 16, 2020 by CapitalTruck