Weird noise? could have a mouse in there, please explain. The tensioner; Make sure it is not too tight on the chain, take the roller apart and make sure you have lots of grease, make sure you are using washers and lock washers, most would say use loctite.
Depending on what side the nut is on, take the bolt out and put it in the opposite way, so the nut is on the other side. make sure you have grease on the roller where it meets the chain.