Timing chain

[Jerry Eads]

I have had the list-discussed timing chain noise on startup prior to oil
pressure, which I'll get to fixing soonest.  BUT recently I've noticed that
at low idle (it's running a bit rough at idle on hot days I just noticed) I
get what I presume is chain slap (a fairly sharp intermittent "clacking"
noise) just below the cams (using stethoscope). Am I in danger of doing
nasty damage if I don't get the thing apart pronto?  Car is '93 SE-R, but
engine is out of a '94 G20.  THANKS - Jerry Eads