Just for reference....this is what a knocking rod sounds like.
YouTube - 97 KenneBell Cobra - 4 valve suffering rod knock..
There's a trick that comes in extremely handy for finding engine noise.
Get you a dowel rod from wal mart, or a hobby store....sand one end so that it has a bullet shaped tip, and use that to find your noise. You can put it to the side of your head over your ear, not IN your ear, and then cup your hand over that. If the rotors are knocking, you will hear it...if it's somewhere else on the engine, you could find it that way.
I'm not sure if you had taken the main belt off as well...but if you are sure it's coming from the driver's side then it may not be the pulley system. It could be a cracked flexplate.
Cracked Flexplate Video
If this is the case....you're gonna need minor surgery. The engine...or the transmission will have to come out to replace this.
