Something In my #5 Cylinder?

Davezilla said

I am not an engine expert, but if it was a damaged rod bearing causing the piston to contact the spark plug as mentioned earlier, wouldn't there just be one mark on the top of the piston? The picture shows damage all over the top of the piston, which seems to indicate something was moving around in the cylinder.

Click to expand...

I'm saying something got in there and it was getting smacked around. You have zero clearance when something is getting smashed between the piston and the head. And the Rod bearing takes all that load.

It doesn't take long beating on a bearing like that before it develops some extra clearance. Not enough to make noise, but enough to let the piston punch the spark plug right in the mouth!