Hey All, Need some help. I have a knock in the engine of my 02 silverado 2500 and my sons buddy said he would find out what the problem is and see if he could fix it. (he does know mechanics). He took the top part of the engine apart and now something has come up and he wont be able to work on it for a while so I am attempting to put it back together.

With all that being said, can anyone tell me what this is? It pretty much disintegrated when I touched it to get it out.

EDIT: I found out what it was and what needs replaced.