i just picked up a 03 f150, 5.4L, 4wd the other day. 177k miles on it. it runs great in town, but once i hit over 45-70mph or so is makes the most obnoxious noise ever. it makes a "waaah waaah waaah" noise. i took a video, and in the video you can slightly here is, but i can promise you, in the cab, is is not slightly noticeable. also, i can feel a vibration that goes to the same tone as the noise in my feet.

any help identifying the problem? i thought maybe tires, so i swapped a good set of tires on it (not new, but better then what i had one it) i drive the truck 60 miles a day, and this noise is driving me crazy!!

http://s265.beta.photobucket.com/use...96e5e.mp4.html

 

the front bumper plastic is broken, and i took a look at it today and noticed the front tow hook was missing, upon further inspection, the frame (where the front tow hook bolts in) is bent...could this have something to do with my noise issue? maybe something broke/bent? if so, what/where should i be looking for?