OK, I changed the thermostat and topped off the coolant in the reservoir. Temp guage still pegs to high when keyn it turned. I'm out driving today and oil temp light goes on, check engine lightgoes on and starts running weak and kinda rough. I pull over at the gas station I was headed to. While getting gas I remember I have my harbor freight OBD2 code reader. I plug it in and pull code P1299 CHT over heat and no other codes. I clear the code and leave the reader attached. I set it to read live temperature output. Temp ranged from 170 parked, 195 to 205 with a peak of 212 going up hill. No further codes and no leaks. I'd love to know what is going on. the prior owner said it likely had a blown headgasket. No visible leaks, now exhaust cload of any color. There is a noise from the passenger side, that sounds like an exhaust leak to me. Looking for pointers of dirrection to persue. Truck is a 1998 XLT with 4.6 liter and already changed the temp sensor(furthest frontward on passenger side with the black 2 wire connector
edit. since purcase the oil pressure reads just below to slightly over the high line.