update: car was left over night not a DROP, I did pressurize the system and left it for the night, NOT A SINGLE drop

I think my car is just a ghost that hates me. When i dont take him out often like i used to, we had Super cold days--- plus I changed the coolant cap, few weeks back, thinking it was leaking from that, maybe it was just crappy old coolant cap that was stuck (not letting any air out)

Whatever, I just keep an eye on it! keep on boost'ing

Cheers!

 

2 things go on after coolant change or the famous hairline crack of the exp tank that only exhibits a leak after being driven and after sitting and coolant cools etc. e.g. "overnight".

its real easy to slightly overfill the coolant and there is a prescribed method for adding coolant after a flush that requires keeping the rpm at +/- 3k while adding. this helps to pressurize the system faster and limit the chance of overfilling it, even ever so slightly. overfilled coolant is going to find its way out the cap, or worse still, reveal any hairline crack in the actual expansion tank.

whens the last time the exp tank was replaced ( if ever? ) and what color is it? brittle aging yellow? or white plastic. if yellow, probably needs to be replaced. that'll fix a minor overnight drip leak.