FGY33 grinding noise at specific RPM's

[sublime187]

i notice a noise when my RPM's are at 1000. not 800 or 1200 , but right at 1000 it's a grinding/somewhat high pitched type of noise. i also hear it at around 3000. but i could just sit there in park and as soon as it passes 1000 that noise occurs very briefly. if i sit there and let the needle sit right at 1000 the noise will be constant. what is it?

by the way, it's not the heat shield. i already had that removed last year. come to think of it, it is a similar noise. but it ONLY occurs at those specific RPM.

[maxnix]

Did you check all of your pulley bearings the last time replaced all of your belts? Any roughness or noise is a sign of failure when they are stressed under load at higher RPM.

[sublime187]

it's not high RPM noise necessarily.

[qship96]

There is more than one heat shield under there- take to local service station and put on lift with you in drivers seat with engine running while technician pinpoints noise from below- might as well change oil/filter while it is up in the air and exposed!!!

[maxnix]

it's not high RPM noise necessarily.

Doesn't have to be. All you here are the harmonics which are amplified at its particualr frequency.