OK - so it started this Sound , like 30 sec. after the OP Delivered & Left ..
Well wouldn't be a Pisser if it was the Air Cleaner : Yeah Right this sounds .. Bad .
Input Shaft Bearing on Trans - as a few Times I let the Clutch out in Neutral it stops
All together .. last like 20 sec. then gone till new time Engine Starts .
https://youtu.be/SWfoJyPSjso
ps: As You can see - If I'm Wrong -I'll say so !
Inspectors are all about the Truth - Period !