Anyone experience a howling sound coming from (what i assume) the fuel pump? I can hear it when the truck is running as well as when the engine is shut off and key is turned just to the accessories position. Im assuming it is the fuel pump because it sounds like it is behind/below the fuel fill door. I didnt notice anything on start up this morning, just when i pulled into work after a 2 hour freeway drive. It sat for 4 hours and it is still happening when i left for lunch. No warning lights are showing on my dash.