I would pull the T-belt cover and look at your pullys to be on the safe side. Even surpentine pullys. It could be purely quincidental that you were under the hood and ths noise started. Our 98 zetec had an ocasional noise I could'nt chase down till too late. It would explain ruogh idol, stalling and some grinding. The bearing will eventualy freeze but the belt will still turn the plastic part untill melting enough to jump a tooth. Let us know what you find???
