HELP Overheating then turn engine off not overheating

I have a 2005 ford expedition 5.4 Triton 275K miles, a few weeks back (05/31/2019) the engine coolant gauge showed overheating then when I stopped and turned engine off the gauge went back to the middle and normal, I would drive for a bit more same thing, NO CODES, NO Check Engine light just the "Check gauges" warning and went into limp mode. The Expedition did this a couple times until I got it home, so looking on YouTube about this issue most stated the cylinder head temperature sensor may have went bad I replaced it with a new Duralast one from Advance last week. I thought all was well as I went a weak no issues,driving interstate 95, towing my utility trailer on I95 and local roads, no problems, but yesterday while on I95 the Expedition did it again (no trailer) just driving, stopped the engine was not overheating, plenty of coolant, turn vehicle off, re-start and back to normal. Drive again same thing, got off interstate and went down local roads and as long as I did not go over 65 the gauge would stay in normal with sometimes going up some and I would slow down and temperature would return to normal. One thing I noticed was the top hose was not like really ridged and other cars I have had in past when coolant is hot and under PSI, the top hose would be almost hard as a rock, but here it has much give to it. Time of this post I am going to change the thermostat as it is only a 30 min job and about $25.00 to make sure, but ANY HELP on this issue would be appreciated or any troubleshooting ideas, if I have to replace the water pump which is not making any funny noise and seems ok. Thanks in advance.

update: 06/24/2019, I replace the thermostat over the weekend, and one note to all who replace bolts on really old fords, PUT A NEW BOLT in it's place, broke one of the 8mm bolts off in the bottom of the housing, but was able to chisel the remainder of the bolt out to where I could get a channel lock on it and twist it out and replace the bolts with new ones. Drove Expedition over the weekend and so far no issues, so maybe it was the thermostat all along, will update as I drive it further as last time it took about a week for the situation to come back.

Was it a no fault thermo you put in? I’ve heard of the no-faults but haven’t had the opportunity to use one yet. If they go bad they stick in the open position so you don’t overheat. Let us no if ur problem comes back.....

I had a no fail kind that I put in a van. The issue is sometimes they fail without overheating, then you have no heat the next winter and get to replace it again. Luckily, that was the one thing on that van that was easy to get to. I won't use one of those again.

Dennis_H said:

I had a no fail kind that I put in a van. The issue is sometimes they fail without overheating, then you have no heat the next winter and get to replace it again. Luckily, that was the one thing on that van that was easy to get to. I won't use one of those again.

Click to expand...

Yep, and with these newer motors everything has to be at a specific temp or they may throw a code atcha, if it’s not fixed soon. Be well...

I put in a thermostat for Advance Auto, a 192 degree rated one, there was no seal sold with the unit so I had to also buy a Fel-pro gasket that look exactly like the old one. The one I got from Auto Zone was the wrong one with the wrong gasket so I had to return that one and Advance hooked me up, so far no issues, no codes, no leaks, no overheating, but like I state it took about a good week for the problem to return and I should know more this weekend as I am using the Expedition to tow my utility trailer a lot.

Update 07/08/2019: After replacing the thermostat the expedition has NOT overheated since this, but I am getting another issue now of
Check Electronic Throttle Control on the warning screen, not sure if something is related or this just a new problem.