2018 expedition max coolant temp fluctuating ....

[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..