If you don't have those symptoms, check your coolant elbow from the LIM to the tensioner for leaks, as well as the radiator cap. Also, the water pump, and the lower elbow from the tensioner to the water pump. If no problem there, check for milky looking oil, or any white vapors from the tail pipes. Read up on this techinfo article. The upper intake will not be relevant - as your supercharger takes its place. But you are just as prone to the LIM gasket problem.