Re: Won't idle code P0308
The cooling liquid temp indicator can not be used to know if the engine was overheated in this case. The problem is that there was air in the system, which would allow locally heating up the engine very quickly. That is the big problem of air in this system. When the liquid was already that hot, for sure the places where no liquid was, some harm was done.
Was the engine idling rough before you changed the cooling liquid? If yes, you should clean the idle Air Control stepper motor and air canal.