[Rev]

I hate to say it but pulling the heads to check for valve train- piston damage is not premature at all from what I've read so far. Something is badly wrong here. I suspect valves kissing the pistons for some reason or coil bind as previously suggested. My advice is not to pussy-foot around on this. Take the heads off and see what the heck happened. With my advice and a couple of bucks you can get a cup of coffee.

Rev