I have a 08 6.4 bullet proof truck I changed my thermostat an filled it back up drove the truck for 30 mins did good then it started over heating again blowing cool air in side while the heat is on the gauge floats an 10 to 15 mins you can drive the truck again the water pump an leaking or making a noise. Some people have told me it could be air locked what do Yall think

 

I had to change my leaking water pump at 108,000 miles on my 6.4, check your fan, make sure nothing is blocking your radiator, check your oil, I've seen cars overheat cause they were low on oil

 

Thank I may have a bad thermostat again