explain how it happens? does the car just slowly get hot? or does it rise very quickly?

usually a fast rise, is an airpocket, meaning you have to burp the system...

When you run the car for a bit and park it and shut it off.. puddles underneath after a hour of sitting or so?

 

Did you put the thermostat in correctly? Who makes the thermostat? Did you purge the cooling system? When does it overheat, sitting still, or while driving?

 

oh, well thats commen sence........ you would think.


i thought he ment in some way a loss of pressure or something would cause overheating.


idk what i was thinkin

 

where'd the OP GO?????????

 

Not directly the cause but definately a loss of pressure will contribute to overheating.
The boiling point of coolant will raise AS the pressure is raised.

Do not know the numbers off hand but without pressure, water boils at 100deg Celcius. Under pressure it's higher.