recently my mustang started making a squeaking noise when i would start it up, it got to the point where my car shut off at a red light. i changed the belt thinking it was that but that didnt stop the squeaking, so i then changed the water pump, and thermostat just incase. but when its cold it starts squeaking again. not as bad as before but that is how it started and progressively got to the point were it shut off. what else could be causing the squeaking?