Temperature gauge behaviour

[seventieslord]

110C is the same as 230F.
Operating temperature for the 10r80 is 205F to 215F.
I do know there is an updated Thermostat from Ford that helped my 2018 Max out before the transmission was replaced. A coolant flush might also help in the spike in temperature. Costs about the same as a Full Synthetic Oil Change.

Have you changed your coolant at all? Notice any leaks anywhere? Turbo fittings could also be leaking coolant just like the 1st Gen 3.5 Ecoboost.

Coolant was replaced with the engine, and the level hadn't gone down, so no leaks.

 

[seventieslord]

This began happening with my 2021 EXP LTD in March, while ascending a hill. I found that if I punch the gas pedal to have it shift into a lower gear, it immediately starts dropping until the numbers disappear. I asked 2 dealers about this and they had no answer as there were no error codes in the system. We'll see how it does this week as I'm embarking on a 2300 mile road trip during some very hot days.

Actually when my old engine was having these overheating issues, I figured that out myself as well. My temperature could go all the way up to 125 and I could floor it for just half a second and the temperature would quickly drop back down to normal level before slowly creeping back up to dangerous territory. I'm not really sure why that would temporarily alleviate the problem, I also don't know if I was making the underlying issue worse by doing it, but it did keep me from being stranded on the highway.

 

[seventieslord]

Up to 22 they had a faulty thermostat simple part probably 20
Minute fix by a experienced technician. $40 part. Ford updated the part in 2022.

My 19 had the same symptoms only I noticed transmission temps running warm when they shouldn’t this was around 65,000 miles. By 75,000 it was worse and spiked engine temp to 235 on a climb with only me in the car in 50 degree outside temps.

Got it replaced and zero warm trans temps now an zero engine temp spikes.

Transmission runs 190-201 all day long 100 degree weather, long climbs etc. Towing it actually cools down from 220
In stop and go traffic to sub 210 while climbing a decent grade with 8700lb of trailer behind it. Never did that with prior thermostat

Replace the thermostat!!! With the new one new part number in picture

Thank you, that's good information and the next time I replace the thermostat I'll be sure to use that one. In case anyone is wondering, last year when diagnosing the issue the thermostat was 100% eliminated as the problem as we were able to run the car without it installed and still duplicate the issue.

 

[DieselMonk]

No, no towing.

Long story short, I had chronic highway overheating, and all the usual suspects were already eliminated. Coolant, leaks, thermostat, rad, etc. Mechanics dug deeper and found a chunk of one piston had broken off and lodged at the top of a cylinder. Became fused there and needed to be bored off. That was an expensive job and the guy they sub that out to eat too busy to even reply. They suggested a used engine would be no more money and would be done sooner. After investigating used engine prices, I made the decision to go with a new one instead.

Was the piston the cause of the overheating or a symptom of it? By this point I can't bear to think about it anymore.

If you didn’t have any engine codes and pics from the damage, it is hard to believe that story. IF a chuck of piston or a piece of the piston ring came out it would be damaged cylinder liner (scored), banged up heads and valves, loss of compression and a rise of oil consumption in that cylinder. The pieces would have gone through the turbo and ended up in front of the catalytic converter.
A slightest wrong and the these an engines start to develop a ticking.

Do I believe what you got told? Not a chance. I would wanted to see the motor as they open it. No codes, No oil consumption to go with this this theory, nah.

 

[seventieslord]

If you didn’t have any engine codes and pics from the damage, it is hard to believe that story. IF a chuck of piston or a piece of the piston ring came out it would be damaged cylinder liner (scored), banged up heads and valves, loss of compression and a rise of oil consumption in that cylinder. The pieces would have gone through the turbo and ended up in front of the catalytic converter.
A slightest wrong and the these an engines start to develop a ticking.

Do I believe what you got told? Not a chance. I would wanted to see the motor as they open it. No codes, No oil consumption to go with this this theory, nah.

It's a little too late to litigate the details of my old engine, but what I can tell you is that I saw the chunk of piston myself in person, and this place had nothing to gain by telling me I needed an engine, I bought it from a third party. And of course, it no longer overheats.