First time caller: I got home from work and noticed a knocking sound on my mazda. Checked under the hood, sounds like it could be a loose rocker(?), noise goes away at higher rpm's. The best part is, it's on the side with the intake/injector sitting over top. How difficult is this repair? Is there somewhere I could get some info, spec's and diagrams online? I'm pretty good with a wrench, but I'm no master mechanic!