I read the detailed write-up on the IWE system here:
F150online Forums > Special Interest > Articles & How-To's
Everything You Wanted To Know About The IWE System....And Then Some!
(great job xjcamaro89)
And I'm curious about this......

If the 4WD is engaged through vacuum loss, then- IF you have a vacuum leak in the system it should start to show up when you 1st start the truck in the morning, after losing vacuum all night.

If this was the case....wouldn't you hear the clunk of the 4WD disengaging upon start-up....as the vacuum builds?

Your thoughts on this.....
Thanks, Marc

 

thanks so much for useful info

 

That kinda makes sense to me. I doubt you would really notice it click tho, cause I imagine it would do it right when the truck is cranked and like most of our Ford Trucks - especially in the morning, they roar at startup, and at least on mine I can't hear anything... On my old 98 expedition, I just hear a bunch of disconcerting clicking noises everytime I crank it, so i doubt I would notice another click...

 

that does make sense, i never hear mine disengage at start up but ill check and see.