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.


Sent from my iPhone using Tapatalk

 

[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.


Sent from my iPhone using Tapatalk

 

[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.


Sent from my iPhone using Tapatalk

 

[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.

 

[Calidad]

The shutters are a known issue on the smaller cars especially in areas with parallel parking. Lots of busted shutter systems due to cars backing into the front of parked cars. With the Expedition and having a better bumper and more space behind the bumper, it could be a fuse or mucked up shutter thats stuck.

 

[Gumby]

I had this happen to mine. It was a leak in the coolant hoses. It had to be done twice...

 

[Blackshirt5598]

Not seeing any fluid or leaks anywhere. The very bottom shutters opens when engine turned off. When turned on the very bottom close, I turned on A/C full blast and the very bottom shutters stayed closed. Thanks for all the help

 

[wakeboarder]

Not seeing any fluid or leaks anywhere. The very bottom shutters opens when engine turned off. When turned on the very bottom close, I turned on A/C full blast and the very bottom shutters stayed closed. Thanks for all the help

Bottom shutters are for the intercooler, so they probably stay shut until it boost.

Does your radiator fan kick on with the AC?

 

[Gumby]

Not seeing any fluid or leaks anywhere. The very bottom shutters opens when engine turned off. When turned on the very bottom close, I turned on A/C full blast and the very bottom shutters stayed closed. Thanks for all the help

Neither did I. Apparently, it only leaks when the system is pressurized.

 

[Blackshirt5598]

Bottom shutters are for the intercooler, so they probably stay shut until it boost.

Does your radiator fan kick on with the AC?

I’ll check tonight.....

 

[donnie24]

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

Resurrecting and old thread.
Just bought a 2018 expedition and having the exact same problem you are describing. Did you ever find resolution to this issue?

 

[Soliyou]

Resurrecting and old thread.
Just bought a 2018 expedition and having the exact same problem you are describing. Did you ever find resolution to this issue?

This is the thermostat sticking. Ford updated the design slightly with thermostat RT1252

 

[donnie24]

This is the thermostat sticking. Ford updated the design slightly with thermostat RT1252

I should've mentioned I already changed the thermostat and saw no improvement. Also have checked and monitored the shutters-wide open going down the road.
Radiator seems warm on the upper hose and cool on the lower hose so have ruled that out.
Would like to get my hands on cooling system diagram of this engine to decipher the rats nest of tubing and how it's supposed to work.

 

[silverx0ne]

My 2018 (hd tow) does this as well. I towed about 7k about 1300 miles and had this occur under load (grade). Once leveled out back to showing no numbers. I am now noticing it during regular driving when boosting and up grade (even without towing). The actual gauge stays perfectly center so I've always assumed it was still good to go. My coolant levels are normal, car heats up and cools off fine.

Interesting thread..