Anyone have any thoughts on what I'm dealing with?

[elmo2297]

So my wife has a 2003 Ford Expedition 5.4L Eddie Bauer 4X4 and I'm more than certain that the front passenger side hub assembly is going out in it but before that I was driving it and I ended up noticing that when in 2wd and while accelerating it sounded like lifters ticking, and the ticking got faster when accelerating just like lifters or a minor engine knock like it was low on oil. Well I checked the oil and it was still full and like new well then I got the bright idea to put it in AWD and the noise completely went away. What could that be?

 

[99WhiteC5Coupe]

So my wife has a 2003 Ford Expedition 5.4L Eddie Bauer 4X4 and I'm more than certain that the front passenger side hub assembly is going out in it but before that I was driving it and I ended up noticing that when in 2wd and while accelerating it sounded like lifters ticking, and the ticking got faster when accelerating just like lifters or a minor engine knock like it was low on oil. Well I checked the oil and it was still full and like new well then I got the bright idea to put it in AWD and the noise completely went away. What could that be?

You have a vacuum leak in the Independent Wheel Engagement (IWE) system.

It could be a vacuum line, a vacuum check valve, the IWE vacuum solenoid (mounted on the firewall), or the IWE hub. The most likely culprit is a line, valve or solenoid.

There are MANY posts on this forum regarding the matter. Do a search and some reading - you’ll find the answer.

 

[99WhiteC5Coupe]

So my wife has a 2003 Ford Expedition 5.4L Eddie Bauer 4X4 and I'm more than certain that the front passenger side hub assembly is going out in it but before that I was driving it and I ended up noticing that when in 2wd and while accelerating it sounded like lifters ticking, and the ticking got faster when accelerating just like lifters or a minor engine knock like it was low on oil. Well I checked the oil and it was still full and like new well then I got the bright idea to put it in AWD and the noise completely went away. What could that be?

What did you determine?