I have been having like a high pitch noise on the passanger side under the hood, however it is not the belts or tensioner pulley. I have replaced all belt and the bearing in the pulley and the noise remains. My car is an automatic and it will make the noise in drive when I am slowing down (might make it all the time but I can't hear it over road noise, im not sure). Also sometimes it will make the noise in neutral and park but if I rev the engine up just over 2000 it will stop, then as the rpm slow the noise slowly comes back. It sounds almost like a squealing but I can not find it. From previous posts people have told me it is more than likely my altinator however using a screw driver as a stethoscope I hear nothing from it. If anyone has any idea let me know. thanks Bob

 

anyone have any ideas?

 

It seems my car is having the same problem. It sounds more obvious when I am in the car than out there looking under the hood. Any one had this before?
TIA.

 

Dont worry that's just your supercharger.