1996 explorer 4.0 v6

Do you own the vehicle or looking to purchase it. Addressing the temp question. I have a 96 and 99 Explorer. As long at the needle is between the two hash marks it is considered within the heat range. If the temp need fluctuates, changing the temp sensor is a very inexpensive example of "throwing parts at a problem" to see if it fixes the problem. I doubt it has been changed in 32 years.

Thx O.J....Actually I inherited it from my aunt who passed recently.. so missing some info...But it was a connection we had, since I've owned a 96' V8 XLT/AWD for bout 13yrs...& she's the original Owner of the V6 version. I mention all that cause She "LOVED" Her truck & Explorers period! And she Drove ALOT! (260K on O.D.) It was her Baby? And she threw ALOT of money at it for Maint. or any tiny squeek becuz of all the traveling etc. ( Never seen another like it?) Anyway I Assume' that's why all the New Parts etc? But I have no idea if she was even aware of the ERRATIC Temp issue? Or if that's why the New pump etc?? So far I've just going through everything to see whats Going on? So far I have changed out ONLY the Thermostat myself? (Jst In Case?) But like said? Everything looks Good or new, runs smooth as glass etc...YET' H2o Gauge quickly rises to almost Over heat'n RED zone! Then drops again etc...No other symtoms, etc..?? And I just mentioned the "Sensor" C/O in case anyone's delt with this before as a possible cause?? I've never been a Fan of the ford V6! Waste in my opinion. But this rig is special & I'm hoping i can save it?? Something ain't right?? What am I missing?? Thx PhylO