The steam came from underneath the head, probably the head gasket area. The noise was definetly steam hissing out, I did not hear any mechanical type of noise. The car was running and the bleeder valve was open, alot of air was hissing out, and all of a sudden I saw the steam coming from the head area and I almost pissed in my pants. I shut the engine off and immediately posted my situation on the Board. When I went back outside after letting the engine cool down and started the car. I noticed that the thermostat to expansion tank hose was leaking at the thermostat connectionm, maybe to much pressure, I needed to replace that hose anyway. I changed the hose and added water to the coolant system. I let the car run until it warmed up and then bleed at the thermostat valve. Air was released from the system and the Temp. Guage measured 1/2. What do you think? All I wanted to do was bleed the system of all the brown sh-t and then replace the old radiator, half of upper nozzel broken off, with my new one, Valeo. After looking at the radiator setup I am wondering if I can change the radiator myself. If you can give me a vote of confidence I would appreciate it(Step by Step instructions needed). Are you familiar with the Valeo Radiator because when I took it out the box to compare the connections I noticed that the Valeo drain plug was a plastic nut that did not come off. The O.E.M radiator drain plug unscrews for draining the system. Do I have the right radiator or should I send it back.