Ford Ranger

I just got home from Iraq and bought a 1992 ford ranger. It has a V6 2.9 with 4X4. With the heat of Arizona going up I have noticed something with the truck. When it is hot out and I have the ac on the truck will get very very hot. Not to the point that it will boil over when it’s on. But when I shut the truck off I hear a boiling sound and sometimes it boils over from the overflow box. I had the thermostat changed about 4 weeks ago. I think that it has a new water pump and I need to get the valve cover gaskets changed. I don not know if this would cause this. Can you help?
June 24, 2006.

Check out the related content below while we wait for the question to be answered by a professional mechanic.