Proper operating coolant temp for a 2010 Ram 1500 5.7

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Bigskyroadglide

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In my humble opinion, you've owned the truck for a year. You're approaching 100k.

Change the T stat, flush and fill the cooling system and then you will know.

Otherwise you are guessing.

If it continues to exhibit the behavior, then it's something else.

A flush and fill with a new t Stat is reasonable at 100k on the clock. Especially if it gives you peace of mind.

PS, the stock tstat is 203 degrees.
 
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My2010Ram

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In my humble opinion, you've owned the truck for a year. You're approaching 100k.

Change the T stat, flush and fill the cooling system and then you will know.

Otherwise you are guessing.

If it continues to exhibit the behavior, then it's something else.

A flush and fill with a new t Stat is reasonable at 100k on the clock. Especially if it gives you peace of mind.

PS, the stock tstat is 203 degrees.
That’s what I was thinking too, it’s time for the big tune up. If I knew that the swing in temp that I have been seeing is relatively normal then I’d leave the Tstat alone and just flush the system. But for a $10 part that relatively easy to get to I think it would be a mistake not to change it since the system needs to be emptied anyway.
 

Tominator223

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I have a 04 5.7. I run the 180 or 190. It hot climate se tx. I did this to avoid the valve seat issue. (In 3rd gen) However you may just have a bad sending unit(sensor). Or sensor may just be lazy. That’s where I’d look.
 

crash68

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I’ve noticed in cooler weather my highway driving temp can be as low as 175 degrees and then when I sit long enough it can climb up to 203 (never seen it higher than that). I usually let my truck warm up for 5-10 min in cold weather but if I don’t and pretty much getting going shortly after starting the truck I’ll get a CEL after a few miles that says that my engine operating temp is to low.
You already spelled out the problem, when your getting a CEL because the ECM is saying the temperature is too low then it's either the thermostat isn't working correctly or the coolant sensor is bad. Since you'll need to drain the coolant down to change either one might as well do both, use Mopar parts.
You shouldn't be seeing a CEL if you don't warm the vehicle up, I've had a similar code on other vehicles and the fix was the thermostat.
 

Serespecialist

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I’m from Florida and when I visit North Dakota I put cardboard in front of my radiator so I have heater working otherwise it blows cold air lol
 

Rambo71

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I just had my water pump replaced, they did the thermostat while they were in it, it runs consistently between 198-204, climbed up a mountain and saw 210 once.
Also check your active shutter system to see if they removed or disabled the shutters. Could be wide open shutters with a 180 thermostat.
 

GTyankee

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When you do decide to to change coolant

You should back flush the heater core, that is the 2 hoses that pass through the fire wall.

You should be using HOAT Coolant in a 4th Gen 2010 Dodge Ram
this will work properly for your truck
Zerex G-05 by Valvoline
Valvoline actually makes HOAT for MOPAR

Spend a bit more & get the correct thermostat for your truck

Good thermostats made in recent years, when they FAIL, they fail in the OPEN position, unlike thermostats of the past, that failed in the closed position :(
 
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My2010Ram

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Finally got around to to doing the job, running at proper temp now and getting there faster. I replaced my tensioner and idler pulleys, pvc valve, the old pulleys were fairly worn out. I discovered my water pump pulley bearing was going bad too. It wasn’t leaking yet but there was just enough wobble on the pulley that I knew what was coming. So I replaced the water pump and put a stock temp t-stat as well. Sounds a lot quieter and the idles feels smoother too. Wish I had done this several weeks ago before the cold snap. Now all I have left is to do the spark plugs. Thanks for everyone’s input!
 
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