Havent ran in a couple days just sitting in the driveway. Opened the rad cap for no real reason. Coolant comes gushing out. Not a massive explosion but enough to get a bit on the fan and the alt.
reading seems to indicate a head issue allowing combustion gases in. However as I mentioned the engine has been of at least 4 days. Wouldn't any supposed gases have worked themselves out by now?

​​​​​​Rad cap was recently replaced. Recently flushed out coolant as can be seen in my previous thread history. Oil is two months old rotella has a bit of a olive green color to it. No mayo no milkshake , nothing else of about it. Don't see any swirls under the rap cap or in the overflow tank.