Mysterious high temperature situation with DD15

Going thru a high temperature problem hoping someone here can help. Truck is a deleted 2013 Cascadia DD15 with inframe done about 90k miles ago. I was loaded, my temp was rising, moving higher & higher. It stopped & hovered in the 225 degrees area. Water pump is OEM about 2yrs old. No leaks. Just had new OEM thermostat & coolant temperature sensor installed today thinking this was my problem. It seemed to work. Drove around to bring up temperature up but it stayed kinda low between 185 going down to 160ish. Which seemed odd but I figured it had to do with being a new thermo. Made sure coolant topped off. I drove about 45min to deliver my load. Seemed to run kinda high about 200/205. Normally would be about 195ish. I offloaded & I'm driving back empty & needle is rising to about 210 then hovers to 215 to 220 & goes up & stays hovering about 225 again. Don't know what gives. Defective OEM thermostat? Inside impeller of the water pump broke off maybe? Plugged up coolant filter? or something else. I removed my coolant filter and drove about 15min that way. no change. I'm wondering if the water pump impeller had broke off inside so not able to push coolant thru system could this spike in high temperature kill a thermostat? Maybe killing my old & new one causing them to stay closed? The top of my radiator & hose going to egr cooler/head is hot. Bottom of my radiator & hoses/pipes going to thermostat housing are cold. Thermostat feels hot. Belts are present & intact. Fan is on. No coolant being pushed out of reservoir. No bubbles in coolant or oil present in coolant. No coolant present in oil (thank God). No white smoke in exhaust. Very confused. Another problem is that thermostat was last one dealer had. Theres none for hundred's of miles around me. I'm in San Antonio. I'm thinking to take old thermostat & drilling out the plunger & letting it free flow for now. If that works and there's flow then culprit bad old thermostat & defective new thermostat. Or if no change it's a bad WP. What do u all think? Any help would be greatly appreciated.

 

Solved!

The fan was kicking on. The radiator wasn't caked up with mud or debris or anything.

So for anyone that has this issue in the future. Turns out Freightliner uses either the same identical sensor or same looking sensor for the coolant temperature sensor & about 2 others that I could see. One on the housing the thermostat mounts to & another right by it on the block. The truck sat off all night & when I went to start it immediately shot up to 200 degrees! It had to be the sensor. Mechanic changed the one by the thermostat housing. Made sense to me too. But that wasn't it. Didn't get a code so I imagine it's the same exact sensor. Dealer was clueless as to where the sensor was located. I tried driving to the mechanic shop like this but the needle soon pegged to the red triggering an engine shutdown. I stated pulling pigtails off of sensors till I saw the needle go dead. Turns out the coolant temperature sensor that the gauge/ECM goes off of is by the top radiator hose where it goes into the head just below the egr cooler facing the fan. With the plug disconnected I was able to drive the 7 or so miles to the mechanic shop with a check engine light. So if u ever get temperature symptoms like this change the correct sensor out first. Hell if those other sensors are really identical u could probably test swap them too. Having some rubber stoppers or foam ear plugs will help swap out the sensor without losing too much coolant if you don't want to drain the radiator. There's also a copper crush washer that the dealer forget to provide with this sensor. I cleaned it off & reused mine because I had no choice but best to get it if you're at the stealership. Also use a small side angle pick tool to gently pull the grey tab out then pinch the grey tab to squeeze the black plastic clip underneath. You can also maneuver the pick tip in the front of the plug where the clip locks to the plug & get it to release that way too. But seeing as how these old plastic plugs gets pretty brittle with the heat of the engine no matter what you do they'll still break like mine did. In that case wrap the plug head on the sensor twice with electrical tape & the plug will fit tight. So I did the thermostat for nothing but at least it's a preventative & it's one less thing to worry about.