I have these wrist pins for a stock 2.0 six cylinder motor. Most of them have a slight etching to them. I'm not sure of the history of the motor so I don't know what might have caused it. I suspect water. Does anyone know what might have caused this? Should I continue to look for replacement wrist pins? Or use these? They can be slightly felt with a fingernail.

Keep looking for a flawless set.
I have ruined a rebuild in the past due to a wrist pin failure.

Yeah, I know/knew what the answer was, but just thought I'd check. Kind of a wishful-thinking post.

Could it be from water/moisture acting as as an electrolyte and the two dissimilar metals acting as an anode and a cathode? (Tool Steel VS Aluminum?)

This kinda makes a battery of sorts. Usually the aluminum turns to shit first as it breaks down faster. The wrist pin damage could be from this galvanic action.

Ive seen that before. I just can't remember what the hell the outcome of the research was... JeeZzz i'm getting old...

Twystd1