overheat
 

Soo today I was driving on freeway about 75mph nd it was fine but suddenly looked down nd it had red lined pulled over heater blew cold full coolent except when I opened it alittle had some come from overflow as expected but let it cool for a min till half way nd drove home nd its fine now just change thermostat 2 days ago it was fine till today nd previously it had been getting real hot that's why thermostat was changed. Anyone have any ideas what might be wrong?

overheat
 

Check to make sure you bled all of the air out of the coolant system. Check the water pump.

Louds like an air pocket. Rebleed the system

Oh yeah thanks guys