Coolant leaks and temperture fluctuates
 

I have put new thermo in my 01 dodge and new pump and nothing has helped... I got a bad leak somewhere but when the thermo is stuck open it doesnt overheat but still leaks but when closed it heats up to 240. Ive pressurized the radiator and cant find any leak whats the prob here?

I'm having the same issue at the moment , sounds like your sensor could be going bad. Unless your running after market gauges, then idk. I ran the codes and got a p0118 code which was ect sensor excessive voltage mine came down to the wiring going into the connector that plugs into the sensor itself has come apart causing a bad ground/short circuit.