2011 humming noise, low speeds and goes away in 4wd
 

Hi,

I'm noticing a low humming noise when initially driving my 2011. When going at slow speeds (especially noticeable when coasting after acceleration, I get a humming noise that goes away when wheel is right of center. I can also get it to go away when dropping into 4wd (regardless of wheel position). Two shops have said they're not sure what it is and to wait until it gets worse. One shop specifically looked at wheel bearings and ruled those out. It's cold here, which may be a factor.

I'm leaning towards IWE related issue...perhaps losing vacuum? The sound isn't a high pitched metal grinding noise but rather more of a low rumble, again, that I can steer out of. Its like the 4:32 mark , but I didn't hear any of the other noises in the video or other videos with IWE noises.

TL;DR truck making rumble/hum at slow speeds, in front, can steer right to get out of it or drop into 4wd to get out of it. Comes back when correcting the steering or back into 2WD.

Thanks!

i think it is something vacuum pressure related. do you have a vacuum pressure guage?

I just got one! I'm going to test the line coming off the IWE solenoid to see if it holds pressure then directly on the IWE itself. Should I do anything else with the vacuum pressure gauge? Thanks!

not right now. let us know what the psi is