Erratic Coolant temps?

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SVTLOPEZ

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It’s been doing it for about a week now, but every time I hit 70mph for 20mins, my coolant temp shoots up to 226-240 for a few seconds and then backs down to normal. Funny thing is, when It starts to slow down (say when I Vance cruise control) it increases drastically. I’ve checked all the fluids and everything is good. Shutters are not clogged up either. Let me see if I can attach a video. Has anyone ran into this situation? I heard if you change the thermostat to a T-170, I won’t have that problem but the truck only has 45k miles and under warranty. It’ll be going in Monday. Thank you for the help

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digscruze

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It’s normal, these trucks tend to run hot, even under cruising speed. Is this a new occurrence or something you just noticed?
 
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SVTLOPEZ

SVTLOPEZ

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It’s normal, these trucks tend to run hot, even under cruising speed. Is this a new occurrence or something you just noticed?


My alavamche gray raptor did the same but I think I’m gonna go with a 170* thermo
 
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SVTLOPEZ

SVTLOPEZ

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Came back from the dealer today and they said it was normal. I’m definitely changing that thermostat though
Seeing the temp shoot up to the 230's for just a few seconds then right back down is not normal. Sounds like an air bubble in the system. Was there any work done to the truck recently?
 

letsgetthisdone

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Came back from the dealer today and they said it was normal. I’m definitely changing that thermostat though

The OEM thermostat is 190*, changing the thermostat won't do anything, you're already 40* over thermostat temp. It is not normal to spike 230+ degrees while cruising 61mph on the freeway.
 

RivRaptor

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Thermostat could be sticking or and air bubble in the system. Food for thought: Living in SoCal and traveling to the Colorado River and Baja I see temps upward of 126 degrees with long freeway hillclimbs (sometimes towing) frequently, so.......soon after purchasing my 18 and discussing my disdain for the shutters with the local Ford dealer they informed me that Ford told them (dealer) on a couple of hot running trucks to actually remove the shutters (true story). Anyway I installed a 170 thermostat and removed the shutters and turned on the temp numbers above the gauges. Immediately after install I saw erratic temps. So i parked the truck on an incline and opened the coolant reservoir and turned on the heater then brought the truck to temp. It helped but had Ford check it out anyway because they told me there could still be a air bubble in there still because there are a couple of valves in there that if you don't open up at the same time you won't properly purge the system. Ford checked it out at my oil change and said all good. Well after after 30K miles of driving on the 170 thermostat the truck runs at 196 at freeway speeds, a little more passing or hills then right back down and if you coast down a hill or come to a stop the temp will drop to almost 170 but once your back on the throttle back to to 196ish quickly-(I never changed when the fans come on). Driving in temps plus 110 degrees and I see 201-203 with drops below 180 if coasting, but right back up when on the throttle again. Sorry for the long post hope this helps, also the numbers above the swoop gauge tend to show a wider difference in temp then represented in the swoop indicator.
 
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