Years ago. I worked on a ferd 300ci straight 6. The guy said it was down on power, but had no strange noises in it. When I removed the head. I had two pistons at top dead center.
Turned the crank over by hand, and watched all of the pistons move, but #6. Removed the oil pan and everything looked good.
Unbolted the rod cap from #6 and pushed the piston and rod up. What happen was the piston broke in two at the oil ring land.
No damage to the cylinder wall. Got another piston and new rings and install it.
Hopefully your motor could be like this.
