[Jinster]

Thanks for the replies, guys.

I drove the car out with trepidation this morning and so far, all is well. So a gas bubble pressure overflow sounds like what caused it. I bled the cooling system last night and heard some bubbling noise when I opened the valve.

My coolant cap ends in 01.and there were a lot of condensed steam on the rear trunk lid, so I guess that cap is no good. Getting a replacement today.