the thing is the sound only lasts for a minute if not less. So the last time i heard it i got out of my car really quick and popped the hood and tried to look for the sound and then it went away. the sound is only there when its really hot outside and at low rpms. so if i drive the car around and then park it outside for a long time. and then 3 hours later come out and crank her up the sound will come on for a minute and then go away.