am actually afraid of the worst outcome. the coolant is clean cause i drained some the other day but there is some light brown residue inside the reservoir tank. not sure if that makes a difference. could there be major damage even though it never got extremely hot? and what is the temp line between 80*C & 120*C? my buddy gave me an extra auto parts store T-stat that am thinking of drilling 4 hole and see how that turns out. any other suggestions? dont want to start blowing money, hard times