2018 expedition max coolant temp fluctuating ....

[Blackshirt5598]

2018 max with 22k miles—-Not towing and whenever I accelerate going on highway (turbo engaged) temperature shows 232 (highest it went was 238) and then whenever I let off gas goes back to middle and no number shows. Is this normal for everyone else? No leaks and coolant level is at max

 

[99WhiteC5Coupe]

2018 max with 22k miles—-Not towing and whenever I accelerate going on highway (turbo engaged) temperature shows 232 (highest it went was 238) and then whenever I let off gas goes back to middle and no number shows. Is this normal for everyone else? No leaks and coolant level is at max

I don’t have an answer - but how long are you accelerating with the turbos engaged?

 

[Blackshirt5598]

maybe 5-10 seconds....

 

[cmurphy2]

That’s pretty hot for normal driving (+20 to 30 degrees) from my experience. Its also not normal for no numbers to show if you have the temp gauge number view selected vs the bar display. I have never seen numbers pop up on the display when I’m the bar gauge view. I would take it in for diagnostics.


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[byathread]

https://youtube.com/shorts/xfH7R9rYxSU?feature=share

I've only ever noticed this when towing and under a hard engine load at cooler (45-55 F) ambient temps. Never when not towing. The video is the tail end of it going up to 234 (highest indicated it went) and coming back down dragging the camper back up from FL to PA in January. Just had to floor it up a slight grade to make it happen and wife was on the camera work. I was driving and asking her to record/hold the phone. 234 would routinely pop up and then drop through 232, 230, then 228 and then back to "normal" no temp indicated. I didn't notice this happen ever running the AC and dragging the camper from PA to MT/WY/CO and back to PA mid July too late August last summer. Thus my ambient temperature theory.

When towing at momentary loads, I'm ok with it.

Is 238 high enough to be abnormal/in the red? If so, in your situation I'd be inclined to at least rule out the usual suspects. Maybe just check your coolant levels and then the thermostat (or just swap it out). Might be sticking... That happens, I know some run a lower temp one with certain performance mods.

Good luck!

 

[Fozzy]

When the temp numbers show up it means you are approaching the danger zone. Have you checked your shudders? They may be stuck shut.


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[Blackshirt5598]

Shudders? No idea what/where but I’ll research, thanks

 

[Fozzy]

Shudders? No idea what/where but I’ll research, thanks

Behind the grill there is flaps that open and close to help regulate the temperatures. If they are stuck shut it may cause it to over heat under load. I think they cycle when you first start it when it’s cold. they open as the engine warms up. And close again at freeway speeds to help aerodynamics. I also spelled it wrong ,It’s shutters. I think Ford calls them active grill shutters.


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[Blackshirt5598]

Ok, so when engine is cranked the shutters move up and down and then after 10 seconds the upper ones stay open and bottom shutters stay closed, is that normal? Couldn’t find anything that describes proper shutter at start up

 

[5280tunage]

Based on this video ([Driving Assistance] Active grille shutters - YouTube) - maybe you can have someone stand up front at cold start up, look at the shutters, then do things like turn on AC etc. and see if they operate properly.