Just went for a drive and a weird rattle....Alright, here's the scenario(96 d16y8 110xxx miles):
Clutch out, out of gear - Rattling noise at back of engine but inside. goes w/ the RPM of the engine.
Clutch in, no rattle. sounds fine.
Very low RPM while driving, same rattle.

Never really thought about clutch fluid til now, since i've never had an issue with it....but its too dark to check...gonna check in the morn. any ideas?