whoa stop right there!
don't pull anything off or try to diagnose it yourself.
you need to be a lot more specific of what the noise sounds like, because engines make endless noises therefore it's difficult to diagnose.
a lot of the noises come from just normal wear, tear, and age so it's nothing to really be too concerned about.
but if it's that bad that you have to figure out what it is, take it to someone. i don't suggest just randomly pulling things apart and trying to diagnose because there is a lot more to it than you can imagine.
if u give a better description i could probably help you out. just try to listen to where the noise is coming from and describe it better.