Just got the results back from the shop.... It'* not the head gasket.

It does start to fill the resovoir but I don't think I've ran it long enough to see if it floods it. What do you mean by "throw steam'?

Gets hot enough to blow steam through the pressure cap into the reservoir. There may be a problem here, but I am really doubting it. The purpose of the reservoir is to allow coolant to go in when cold and out when reaches operating tempeture and compensates for the surge of the thermostay opening. I remember my *-10 hitting 225 by the gauge briefly at times , full of quarry stone in the summer, and not blowing the relief valve in the pressure cap. If the car has a new thermostat, runs ok, and holds coolant.... I would drive on. Did the full time fan switch help?

I don't know about the switch yet. I only drove it to the shop. I have to pick the car up now.

I think my car is doing the opposite of what you described. It'* putting coolant into the resovoir when hot.

Once the expected pressure of the cap is exceeded the excess coolant will be pushed to the res. This is why the hot full mark is higher than the cold full mark.

LOL!, We have our wires crossed here Nashville.... I meant coolant goes into engine (not the reservoir) as it cools and pressure eases, and back to resovoir as the engine gets hot and pressure builds.

Have you tried something as simple as replacing the radiator cap? From what I read, it sounds like the same thing that happened to me in my Bonnie just last spring. I tested the thermostat, It was ok, The water pump was new, and so was the radiator. So, replacing the cap was the last resort. So, thats what I did. It worked!