Picked up a 94 civic ex sedan over the weekend. When it's cold idles great. Once it warms up it idles like shit and has a knocking sound. Sounded like it was coming from the top end. It only does it once the rpms drop below 1k( aleast really audible). I pull the valve cover and see nothing wrong. Check all the the tolerances and everything looks good. I put the valve cover back on. I leaned on the motor and rocked it some apparently. I heard whatever it is move. Identical noise when i shake the engine as when it's running. So i'm guessing i need to pull the pan and check it out. Going to be #4 from the sounds of it.

What do do you guys think?