A method and a system for reducing belt noise in an engine, wherein the belt is engaged with an alternator includes a transmission upshift detection module determining a transmission upshift or a quickly closing throttle detection module determining a quickly closing throttle. The control module further includes an engine speed prediction module determining a predicted engine speed in response to determining a transmission upshift and an engine deceleration prediction module determining a predicted engine deceleration when the predicted deceleration of the engine crankshaft is greater than a threshold. An alternator control module controls a rotor current in the alternator to add load to the alternator rotor to reduce potential belt noise.