jpnelson1978

my 03 mustang makes a sound only when its cold out, and for about 5 minutes of driving and it goes away. it could just be me hearing things that im not used to on a v8 but would like to know. it doesnt happen if i raise the rpms at idle. only when i am driving in each gear at all rpms. the only way i can describe the sound is ---an empty hollow can with air blowing through it. its not a rattling sound, but more like a low pitched whistle.it sounds like it could be exhaust, but more towards the front of the car. i cant tell if its coming from the motor cause it does not make the sound at idle. so it should not be exhaust either since i do not hear at idle.---also if i nail it i dont hear it. only when i hit the throttle gradually. anybody have any ideas.