I bought a 1990 integra gs with a blown engine. I put in a new engine. started it up. there was a knocking/ticking noise coming from the engine. I figured it was a spun bearing or a stuck/bent valve. I did a leakdown test and it showed that one of the exhaust valves was open on the #1 piston( I'm not too sure I had the piston at tdc though). I took the head off today and the exhaust valves do look like they could be stuck open just a little. there is no damage to the tops of the pistons though. the most disturbing thing that I found is the fact that once pistons #1 and #4 are at tdc I can physically push them down without moving the other pistons. #1 will move about 1/4" and #4 will move about 1/8". there really isn't any damage done to the cylinder walls though. just one or 2 vertical scratches in all 4 cylinders that you can only see, not feel. I think those are from starting up the engine after it had sat for so long. I'm not sure about that though.

so what do you guys think it could be? spun bearing? I wouldn't think the pistons would move that much with a spun bearing, or at least there would be more damage done to the cylinders. I'm kinda lost, any help would be appreciated.