Alright, I've been going through every noise I can find on youtube of subaru engines "failing" and this is almost exactly what I'm getting from my engine, but my motor is MUCH quieter than this one is. I really have to get my head down towards the engine with the hood up to hear it coming from the front left side (low in the engine). They say this is piston slap. http://uk.youtube.com/watch?v=p98AqJhH9Qs&feature=related What kind of engine life am I looking at with this, and what is a good way to fix it? If I can make this motor last until after my first deployment, this car will be getting an entire STI drivetrain next fall.
again, I really feel like erik was right with his comment. It sounds exactly like piston slap, and it is virtually gone once the motor warms up. woot.
one more video. http://uk.youtube.com/watch?v=PMlOemrjyk8&feature=related That is almost exactly what mine sounds like, except again, mine is quieter than that.
Piston slap is a byproduct of having large bores. It is not an issue. Some slap more than others, some don't. I've heard motors that slap continuously even when hot. Still not an issue. Built motors are often louder, due to more piston-to-wall clearance than with cast pistons. Don't worry about it.
OK, so the first video is REALLY loud slap, which I don't hear very often. The second one is very normal. My mom's Forester hammers much louder than that, even when it's 60 degree's out. On some motors, it doesn't go away until you actually drive the thing to get enough heat into them. All it is, is the piston rocking in the bore a little bit.
good. Mine is considerably quieter than the second. yesss I can spend money on exhaust and a tune now. woot.
loose vs. tight motors, its all in the theroy about the build type and persoanl preferance, I wouldn't worry about it.
My old 99rs had piston slap like crazy...nothing ever came from it though. It was just loud and annoying (especially on cold winter mornings)!
