Temps go up when idling quickly, fan keeps kicking in

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enforcer17

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I have not noticed this on my wife's 2019 Ram 1500 CCSB 5.7L, but my 2019 Ram 1500 QCSB 5.7 when idling seems to quickly heat up from 204F when driving to 226F and then the fan kicks in and drops it to 212F, but within about two minutes its back up to 226F and the fan kicks back in.

I know these trucks are engineered to stay in the optimal temp range, but I am surprised it jumps so quickly when idling after driving. Outside temp was 62F today when this happened, noticed it happened all summer too.
 

Dodge 1500 4X4

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Mine does the same thing, I think after its been running for a while and you idle in park there is so much heat built up because they are running at higher temps and the fan kicks in, when you are driving looks at the temps, because of the air flow it cools quicker, I've heard on here our trucks have Active Grill Shutters, I've looked at mine and I don't see any, I'm coming from a 2018 F-150 2.7 Ecoboost with Shutters and 2 turbos that create allot of heat but are antifreeze cooled.
 

crash68

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Does this heating up happen with the AC on or off? The Gen5 Hemi uses a similar PWM electric cooling fan the EcoDiesel uses. Only time I'll see temperature spiking is with the AC turned off completely.
 
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enforcer17

enforcer17

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A/C was off ... Yes, I have the shutters, thought they might factor also
 

crash68

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I bet if you run the AC(or set the air to defrost the front window) your temp spiking problem is reduced or goes away.
It's the cooling strategy of the engine, without the AC on, the cooling fan turns off completely. Previous Gen trucks used a clutch fan but even when not commanded it still spun with the engine.
The AGS is primarily of improving aerodynamics on the freeway, low speed and parked they usually stay open.
 
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enforcer17

enforcer17

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Thanks, I will try that ... thought it odd it would heat up so quickly when the ambient temp and humidity were not high
 
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