when i turn my truck off i can here like a buzzing sound under the hood for about a min does anyone know what this is

 

Not sure, have you tried opening the hood to see if you can figure out where it is coming from?

 

ya somewhere on the drivers side near the manifold

 

I am not sure what it could be. Maybe someone else here will have some insight for you. Good luck.

 

well make model and engine would be a good place to start...I have no idea what you have...?

 

96 f150 302 4x4

 

if you have a metal pcv valve in. it is restricting and building pressure that it cant vent try replacing it with a ford(mototcraft) plactic pcv valve
pcv vavles are a metered valve and aftermarket vavles will cause lots of issues
goodluck

 

and where would this pcv valve be located

 

should be plugged into the passengerside valve cover (right rear) there should be a short hose connected to it..this is what it may look like yours may be silver in color or covered in black grime