Need some help. Have a noise that sounds like a chain dragging/grinding noise. Have been chasing emission and power issues for about a month, this new noise just started out of the blue. Have changed the plugs, oxygen sensors, fuel filter, catalytic converters, and cleaned the MAF. Running out of ideas and money. Hard to tell exactly where this noise is coming from, but seems to be near the door area underneath, but hard to hang out the window and pinpoint. Noise occurs at @ 30-40 mph, when any load or very small incline happens, seems to continue on the highway, just can't hear it as much due to road noise. Have tried jacking up the rearend to recreate in the garage, of course no success. 2007 F150. Any ideas? HELP!!!! Thanks all

 

Is this a 4x4? If so, read here:

http://www.ford-trucks.com/forums/836438-everything-you-wanted-to-know-about-the-iwe-system-and-then-some.html
Otherwise, I got nuttin'.

 

It is a 4X4, am in the process of checking taking it in and out of 4wd now. Thanks for the link, if nothing else, great info for future!! Thanks

 

So just FYI, did test in and out of 4wd no noise in 4wd, noise returns in 2wd. More to replace and test................

 

So, just FYI, replaced IWE, noise still there. Undid vaccuum hoses and plugged as web site instructs, noise is gone, so heading to check valves and/or actuator.