Id be more willing to say its the Instrument cluster. If the temp sensor was actually reading an over heating concern the truck would be in derate, coolant would be boiling out of the degas bottle, it would be mis-firing (these trucks force miss-fire to cool down the engine. No internal combustion no heat, no heat runs cooler) Since you have no symptoms of an actual overheating concern, I just think the gauge is junk.

 

Extra information, the temp sensor for the cylinder head, actually runs from the sensor to the PCM directly. It has no connection to the instrument cluster. So, with that being said, the parts your gonna have to check are the PCM, Wiring from PCM to instrument cluster, and the instrument cluster. So going back to my comment above, your truck is probably not in need of a temp sensor. it would be in derate far before you turned the key on if it reads 3/4 key off. lol

See if there are any codes in the PCM. If there are code start with that if there is no codes then youll have to come back here so we can help you from there

 

Heck I got to reading ford diagnostics for the symptom of "Temp gauge not operating correctly" the test and test steps for this is pretty much, run a instrument cluster temp gauge active command, if it does what its supposed to do put a PCM in it, if it doesn't do what its supposed to do then put an instrument cluster in it.

 

[MENTION=163539]Restof150s[/MENTION] That sounds like the diagnostics manual my ford dealer reads too.




I've never tinkered with the cluster. But observed mine and KEY OFF it is at the "C" hash mark. Soon as I turn on the key, it jumps abruptly and settles back down at the "C" hash mark. While running it comes smoothly up to normal.


I was just wondering ----- that thing looks like the needle could be like a second hand on a watch. Wonder if it has just slipped to the right??
Like my old TV - it just needs a good slap upside the head!! Lol

 

I have no idea what you're talking about.......... I'm not at work reading off the ford diagnostic manual or anything........ lol

 

Hey guys...

I still have not made it anywhere yet. I was planning on it this week but as usual things come up and time is short!! I can say it is functioning as it should. One thing i did notice, which may have nothing to do with anything, is that the warmer out it got the better it functioned. Only when it was cold, around mid 30's or lower it would act up or stick if you will. Could i possibly have water in something that is freezing and causing this? Is that even possible or is this more of a coincident?

Regardless of what it is i do appreciate the help and info..

Thank you

 

I know this is an old thread but I am having the same problem. For a few weeks the truck would read hot but was clearly running fine. It would read hot as soon as you started the truck. Somedays it would read fine, others it woud hot. Then one day the truck wouldnt start. Ended up diagnosing it as the alternator, however replacing that, still had a problem as the batter went bad. Replaced those, truck starts fine. However yesterday I drove it and the temp needle got so high the truck went into limp mode as you stated.

still no other signs of the truck running hot, no check engine light. I looked for codes a few days prior to limp mode happening and did not have any codes. Have not checked since. If you made any progress with yours, your assistance would be appreciated.