Hammersouth

Hi to all i am a new member of this more than adequate community,and i really do need some advice.I replaced my rad last weekend and have done the usual checks of hoses clips and fluid levels,But my car seems to let out a metal like screech as i throttle her up.It seems to be coming from beneath the intercooler somewhere and if i manually rev the motor from under the bonnet it seems to sound out as the revs come back down to idle.It never did this before and i was wondering if any of you guys or ladies could pin point the problem as their is only so many times i can spend searching pipes and clips till gone nine most nights...please please