sometimes the valves can rap pretty hard and the noise is magnified by all of the aluminum, m20 bottom end problems are very rare and when they **** up it's usually exciting with lotsa holes, by far my favorite m20/30 oil is chevron delo 15w40 conventional, it's miracle sauce for the solid lift valve train, old ass wornout motors and fresh all new parts rebuilds all of them have quieted down a amazing amount, i like doing the adjustments with the engine as hot as i can stand at factory spec
all america wants is cold beer warm cat and a place to take a poop with a door on it