I have a 2012 F150 5.0. Lately when stopped at a light, there is a noise coming from the engine. It doesn't do this when moving only when stopped. Any ideas what it might be. I used to work on my vehicles but this noise has me wondering what it is. I don't get any codes on the code reader. I was thinking that maybe it's the fan on the engine. Anyone have any ideas?
Here is an update..took truck to Ford dealer..was checked out. Everything good.

 

not much to go on here. remove belt, see if noise disappears. if it does, you know it is from an accessory.

 

Can you describe the noise? Better yet, have a video of it? Upload your video to Youtube and post the link here.

 

Hard to describe the noise. When stopped, the noise gets louder, almost like a hum that you can hear from inside the cab..it doesn't do it when moving. only when idling at a stop.

 

Rattling heat shield type of sound?