In the process of pulling my motor apart and took off my knock sensor and oil pressure switch. I unscrewed the knock sensor and there is a piece of aluminum round that it was threaded into which was threaded into the block. Not sure if its supposed to be like that or if it acts like a dampener to muff out knock. Anyone come across this

 

Sounds like the previous owner of the block stripped the threading and used Helicoil to fix it

 

+1 check the threads on the block. You should be able to tell if they have been re-taped. I would say yes they have. You can also look at that threaded piece and see if it has a notch or a cut out slot in prolly the top because a heli-coil uses a tool to install it