Thanks. I actually inspected the cap based on old posts here, it looked fine to my eyes...hehe. If the cap is allowing it to boil over into the overflow tank, would I notice any "mess" or wetness anywhere? Is there any way to be certain that it is the cap? Visual signs, etc?

Also, the light has never come on before, although the "running hot" issue has been happening for months and even a couple years really....