I've changed the oil twice now and the noise is still there. Like I said, there isn't anything hitting off of the valve cover, on passenger side, and the car is running fine. I'm worried that I may be losing some power due to whatever it may be though. It sounds to me like a piston slapping up and down, as it gets faster the more I accelerate, but I'm also being told that it could be my throwout bearing. Could this be so? I wouldn't think so but does anybody have any insight on a similar problem like this? Also I am not positive but it looks like I have lost a little oil pressure. Not sure of the level I should be at but I am not willing to add anything to my oil or my gas to remedy this. Any input on this is greatly appreciated.