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Discussion Starter · #1 ·
Is it common to have to replace t-stats at 94k miles? I have a 2016 and for the past few months truck has been a little cool on the edge monitor. Idling 174-176 and running anywhere from 176-179 normal city driving. When accelerating from stop will increase to 183-188 depending how hard I get on it and then cool back to 176-179 within half a mile or so. Thinking I may have have a partially stuck t-stat. Had stealership look at it a few months ago and their response was “no CEL, most likely partially stuck t-stat but we don’t see an issue”.
 

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Thats not too bad i did mine around those miles. But my temp was acting a little more out of control. Now its 179 to 188. One t stat is rated for 180 and one for 185 they could be starting to stick. I would just do them anyways as they are easy enough to do. I have a somewhat detailed thread on here, if you search for low operating temps lml you should be able to find it.
 

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Discussion Starter · #3 ·
Yea figured change them and see what it does. Sometimes has me scratching my head. Temps are usually as described above but today it was 90 out on my way home and kept getting caught at lights and temps hovered 188-192 until I got going no lights and they dropped back to 177-181.
 

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Is it common to have to replace t-stats at 94k miles? I have a 2016 and for the past few months truck has been a little cool on the edge monitor. Idling 174-176 and running anywhere from 176-179 normal city driving. When accelerating from stop will increase to 183-188 depending how hard I get on it and then cool back to 176-179 within half a mile or so. Thinking I may have have a partially stuck t-stat. Had stealership look at it a few months ago and their response was “no CEL, most likely partially stuck t-stat but we don’t see an issue”.

i think the service interval on them is around 100K or so, personally i would consider 94K a pretty respectable life for a part that heat cycles that many times. Id replace them and i bet your issue will go away, even if it doesent, there due to be changed anyway.


Yea figured change them and see what it does. Sometimes has me scratching my head. Temps are usually as described above but today it was 90 out on my way home and kept getting caught at lights and temps hovered 188-192 until I got going no lights and they dropped back to 177-181.

while idling there is a lot less air going through the radiator, so the cooling system starts to heat soak at the red light, when you start moving again and air flows through the stack the coolant temps drop back down. That is normal operation of the cooling system, though its likely made worse by the potentially stuck thermostat, since normally the thermostat would close if the coolant dropped below its opening temp, so the coolant in the block would always hover around the thermostats opening temps. Since the coolant temp sensor is in the block, it will always show the temp in the block regardless of the temperature drop in the stack, so id say this also supports the idea of a stuck open thermostat.
 

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Discussion Starter · #5 ·
Makes sense. I know these things have fluctuation in coolant temp. This all started not long after I had the dealer do a coolant flush or they supposedly did a coolant flush last December. Just has seemed to be getting lower and lower over time. I know t-stats not working properly can cause some weird things on the temp gauge.
 

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Had to replace mine right around 100k mi. Truck was running in the 150-160* range.
 
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