I need some advice on my 3rd Gen

Hey new member here haha. I bought this 97 4runner just about a month ago. Now engine is idling really rough at low speeds and is very jumpy. This went away at higher speeds. Also, I noticed when I turn off the car after driving, there would be bubbling in the coolant reservoir. So I knew something was wrong. Then, started loosing coolant and got the check engine light on for a cylinder 5 misfire. White smoke started coming out of my tailpipe. I assumed it’s a head gasket. So I took apart the whole engine by myself and some neighborly help(I’m 18). Got done to the heads and gaskets. They don’t look too bad. My whole reason for this post is, the piston that was misfiring looks brand new, likes it’s never been used. Is that just because the coolant steam cleaned it?

 

Welcome.