Cooling problems resurface in battlewagon

I thought I was done with this nonsense over a year ago.

SYMPTOMS: At regular driving speeds the temperature is proper. Once the sits in traffic, ie: traffic lights, the temperature goes up. Usually you only need to give it some gas and the temp goes down. As the temp goes up, the heat in the car gets colder.

It appears to be some sort of circulation problem compounded by air in the system. But what caused this and where did the air come from?

I have to dedicate a whole weekend to replacing many components in this system. To get to the heater core I have to pull out the entire dash and center console. Then I have to replace the water pump and timing belt also. Ugh. A whole weekend for sure.