Okay. First, make sure the system is bled (as you read). As far as the heater, check to see if the heater core hoses are getting hot. If they both are, there could be a problem with the blend door. If only one gets hot, the core could be plugged. Next, try flushing the radiator and reverse flush the heater core too. I can't remember if you replaced the t-stat, but that would be a good time to do it if you haven't. If the issue still continues, you need to check things like the cat converter to see if it is plugged causing problems with running and overheating. Also, ignition timing could cause it to run hot. Regardless, based on your description, it sounds like you have an air lock in the cooling system. Loosten the heater core return hose and start the vehicle with the heater on. See if any air comes out.
Thursday, September 1st, 2011 AT 3:50 AM