Below are pictures of what I am assuming is the Timing Chain Tensioner. I have a knocking sounds coming from the Timing Chain and is this bolt what is used to tighten or loosen the tension on the chain? If so, is it the normal right to tighten and left to loosen?

Any help is appreciated..
Stretch

 

Its an automatic tensioner. That bolt only loosens it, so that you can take the chain off the cam and what not (dont mess with it). I think the cam chain is streched and needs replaced, or just the valves re-adjusted. PM me if you have questions bout it