I have been fighting an overheating issue and I did some testing today looking for the problem..I bought a craftsman infrared temperature gun and took the temperature at the header flanges. I made sure to keep my hand very steady and took the temperature at the same spot for each cylinder...my results; cylinder 1 ran (after car reached full operating temperature) around 230-235 degrees while every other cylinder was around 310-315...do you think that this indicates a blown head gasket? and could this be the source of my overheating even if I am NOT losing coolant?