So here is a little back story of what happened. Was on a hunting trip, lines froze and the upper radiator hose ruptured. Replaced the hose added coolant and continued my trip. Truck ran great no leaks no issues, temp was spot on on the highway had good temp and heater worked great. On my drive home stopped to eat real quick, added some oil to the engine and noticed the overflow was empty to I filled it to the cold line, now my gauge goes near hot when I’m driving 30 mph and up, when I slow down or come to a stop the gauge moves to cool quickly and then go back up when I start driving again, the heater stopped working but will get some heat when I drive faster. When my truck cools the coolant is filled all the way, I’m totally confused! Idk what to do now I don’t want to blow my engine. Please if anyone has any help or ideas or maybe had the same issue I could really use help.

 

sounds like its still low on coolant. is the coolant bottle still at the cold line. the thermostat might need to be changed.

 

I would recommend installing a new tstat and flushing your radiator and lines. be sure you reinstall a 195* stat. anything less will cause the engine to run rich and cause poor mileage.

lets hope the water pump didnt take a chunk of ice and fail. that would be worse case i feel.

 

Would definitely recommend getting a "after STAT" temp gauge, it will thread into your water neck that your upper hose connects to, They are cheap and will give you an after STAT temp to compare with your water jacket temp taken from the top of the intake that shows on your stock gauge. Then you can see when your STAT opens and your after STAT gauge starts climbing to your 195 mark. Helps narrow down the whole scenario..... and you get that warm fuzzie feeling when that STAT opens up and the stock gauge falls back into its happy place and your new gauge climbs up to the 195 mark ... Also could you have an engine block full of cast iron sludge in the water jacket.? If your block has never been flushed its possible.

 

I'd bet the water pump has lost a piece of impeller.