when i bought this car at 94k it had a tap when cold that i attibuted to piston slap but in retrospect i think the cylinder was going 30k ago. my new engine has none of that clicking. over the years many mechanics heard the clicking but no one said check it out.
i can’t commment on the cause. during my watch oil changes have been on time, no oil consumption until recently, and moderate driving style. from conversations with mechanics i get the impression that this kind of engine problem, unlike the head gasket issue, is very rare in subarus, if that is a consolation.
you can believe i’m pampering this engine, including following the severe service oil change schedule because of frequent short trips, etc.
steve