camarov8

as i accelerate in my 98 z28 a4 i hear what sounds like a clunky squeal noise under the hood. took belt off and still hear the same noise. this noise is only heard while under load and only in forward gears, and goes away after i get up to speed. as you accelerate harder the noise speeds up. ON the gas pedal you hear it, OFF the gas pedal you dont hear it, and you dont hear it in reverse. what should i be checking???