00 Boxster S coolant over flow

[Chuck W.]

It could be something as simple as the coolant tank cap. Look at the part number on it. If it doesn't end in .04 you have an early one that are known for failing. This happened to me. Start there. Good luck and keep us posted.

[Cunningr]

That was replaced a little over a year ago. Just the strangest problem. I drove it 80 miles in the cool am arrived to my destination checking for overflow zero. Trip home AC same distant big outside temp increase arrive home and over flow. Maybe I will check the cap again I took it off before the trip to verify coolant level. I haven't added any and it still is above the max line. Thanks for your thoughts.