Usually just need to get under, WAY under and push the pedal all the way down so the spring isn't compressed and lube it up. Also rotate the spring with vice grips or something.

Second, you will see a cotter pin under there, (mine was a copper color) I rotated this cotter pin several times, maybe 5 rotations.

This solved all my clutch pedal noises for good, AFTER I took it to the dealer and they couldn't fix it.

 

On my old 240sx, it started squeaking when a plastic piece on the return spring of the pedal broke. You might look there.

 

Mine squeaks...it has for awhile now. I have just gotten used to it...thankfully it has not gotten ay worse.

 

fixed my squeak in under 5 minutes. Turns out when the clutch switch was being pressed, it was squeaking against the plastic bushing. I sprayed some silicon lube on the white bushing and the noise went away.



Confirm where your noise is coming from before trying any fix.