I have this EXACT problem. I thought it was a lim gasket. I bought all the parts and had a buddy do the install. Right before we started to take stuff apart the mechanic noticed the gasket had already been replaced. I dont remember 100% what gave it away but im almost sure that the orange you see in the picture signifies the newer gasket, BUT im not 100% on that.
Do you have little pools of oil around the S/C? I do. I have no idea where they come from or how they got there. Also, check the dip stick. Ive heard that if the oil looks like chocolate milk its got coolant in it.
Someone else looked at mine and recommended that the coolant elbow could be causing the problem.