Problems with Celica ST202

Hello Everyone,

Soon i will leave my Celica at the workshop to get the belt and the CV Boots replaced
Yesterday i also noticed something while waiting at a red ligt, AC on, 35°C outsite, if i put it in Neutral, something seems to Grind very slightly, once i push down the clutch its gone, so i assume it has something to do with that however when i parked it leaving the engine on, i turned of the AC and went to check while it was running in neutral, it was gone too so im unsure, i would love to get everything fixed while its at the shop, any clues and ideas ?