So I have a 2011 Infiniti G37 I changed the cooling fans, the radiator has been changed, all hose for the cooling system have been replaced, heads are not cracked, there is good compression on the heads but it overheats every once in awhile not all the time. Does anyone know bout how to properly pull a vacuum for the coolant system because I’m being told there’s a certain way the coolant supposed to be

There are some youtube vids on how to burp the coolant system. I believe there is an air bleed valve somewhere on one of the hoses as well. You can check the FSM for procedures too.