just happened to me and i waited to long an it f'ed me pretty bad. if u soon to hear a sound from the motor bay like i did watch out. my idler pulley exploded. lost power steering water pump wasn't working an all most over heated. yeah bad new. had to push to a shop an was 150$. but any way it could b the dieing of ur idler pulley. that's the upper top left pulley looking at your motor. could b something less just letting you kno what happened to me. happened at 50,000 miles