To make a long story short I dropped a nut down the intake and did know it and started engine. I heard the nut go through the engine and now I have a knock (I know I was a dumbass). The compression on the cylinder was low at about 90 while the rest were about 120. I already checked the valve train and everything is fine and the it actually runs normal. I removed the #1 cylinder plug wire and the knock just about goes away, I can hardly hear it. Does this mean that it is a rod bearing spun or something else. I am trying to determine what the next step is. Thanks

 

OUCH - bent rod, hole in piston, bent valve, cracked head, ECT. next step for me would be tear it down and see what damage has been done - either way I would think it can't be good -

 

I put a scope down the spark plug hole and didnt see much damage. I did have compression on the cylinder so am hoping there isnt damage that I cant see. I am just wondering if it is piston slap or a spun rod bearing. Either way the engine is not gonna last too long. It has over 200,000 miles so it has had a long life. Sad, it runs so well now that I changed the fuel pressure regulator.