I have a 2004 F150 4WD Lariat that has been making a noise similar to if someone was holding a piece of aluminum foil against the drive shaft as it's turning. The noise is intermittent, ceases when I come to a complete stop and doesn't seem to be caused by doing one thing over another such as accelerate uphill. No mechanic has been able to identify the issue as of yet. Any ideas?
Heat shield over the catalytic converter, perhaps? They are spot welded in place and can rust at the welds, leaving the shield to just float on top of the cat, and vibration causes it to give a tinny high-pitched rattle when you're moving. If you can reach it give it a flick you'll know if that is the source of your noise.
Search Ford F-150 Questions
Ford F-150 Experts