When I rev the engine the is a knocking sound at 3500+ rpm. I dont think it is a lifter cause that would do it at startup and all the way through the rpm range right? And it dosen't do it when driving. I think something might be lose in the engine bay. Any ideas?

Also how do you adjust the air/ful mix. I put premium in it smells like its running rich.

 

First off...Welcome to the board! It's kinda tuff to diagnose over the internet. Is it a klacking sound or a deep knock. If it is klacking then I would say lifters, or injectors (if FI). If it is a deep knocking sound, then worst case connecting rod bearing, Alot of times it truns out to be a crack in the flywheel(ringear) I run into this alot actually. A cracked flywheel can make a noise that would make you think your engine is about to die. HTH