Originally Posted by
johntins
It would be great if you could define "knocking sound" a little more. For me a knock is something drastic, like a run big end, everything else is a tap or a rattle. So, have you ever heard a big end knock? Is it like that? Is it higher in pitch, like someone tapping on a window?
Way too hard to pin down by a description. Put up a .wav file or something.
If your hearing isn't broken, like mine is, a screwdriver works fine, and I'll bet you already have one. Do what Wraithe said, and use it that way.
Wraithe also mentions gaskets. Given you have just done some work in this area, I'd be checking that. A leaking exhaust manifold gasket can sound like a knock.