hi everyone...
long story short I have a s13 sr20det. I've been having this problem since I've owned this sr. It makes a metal to metal grinding noise sounds like its coming from tranny or starter. It only does on crank up and goes away and will happen occasionally. Tranny shifts smooth no grinds in gears or popping out of gear.
here's a vid I found that's really similar to the problem I have.