I've noticed a rattle coming from the PCV valve area on the drivers side valve cover. I have the Ford Racing valve covers, they're only a few months old. I can hear it at idle, it's intermittent, and it's really noticeable with a stethoscope. It goes away if I rev the car up a bit and comes back as soon as it drops back down to idle. It freaked me out at first, so I took off the valve covers to make sure the cams/timing chain were fine - everything looked good, no weird wear marks, chain was fine. I installed hot rod cams a few months ago, the car only has 10k miles on it, it's a 2010 GT. Anybody else notice this rattle with the stethoscope? I don't know if it's normal or not, not sure what I should do.