I have a 2008 fx4 few months back I would hear noise from front end like brake pads rubbing. I would pull over and check only to find nothing. This happened 5 or 6 times. When I went to use my 4x4 this winter nothing would happen no light no sounds like it was trying to engage. I tapped on tc motor no help. I noticed when front wheels turned so did front driveshaft. So after reading more I put new iwe solenoid in and now 4x4 hi light stays on and 4hi is engaged. No matter where I turn esof switch too it stays in 4hi. Any Ideas I have read a lot on here but am confused could esof switch in truck be bad or would tc motor be the culprit? Any input from you guys would help! Also I noticed when I have heater blower on floor more air than usual blows through upper vents don't know if that means anything but have heard vacuum issues may default blower to defrost.

 

Before I say - or you try - anything else, read through this post:
https://www.f150online.com/forums/ar...then-some.html

 

I have read this but not having all the different tools required to test vacume lines Im up against it. If I remove tc motor and manualy put back in 2wd will that work if there is a vacume problem?

 

A coupe of thoughts here. First, remember that vacuum is used to unlock your IWEs. So if you don't have vacuum, your IWEs will be locked. This sometimes messes folks up when they turn the front wheels with the engine off. Engine off = no vacuum = locked IWEs.

When you say that no matter where you turn the ESOF selector, you're still in 4WD, what do you mean? Is the Transfer Case still in 4WD (indicator light on) or are the IWEs just locked? The reason I ask is that you need to separate the problems into Transfer Case, IWEs, the IWE Solenoid or the Vacuum Lines and / or Check Valves.

 

When I turn the **** to 2hi it stays lit saying 4hi and truck is driving in 4hi before I changed solenoid I had no lite other than on start up and truck wasn't in 4wd. I am going to try and take the tc motor off today if weather permits. If that is not it im guessing I have a vacume issue. Thanks for responding.

 

If the indicator light on your dash says you're still in 4High when you turn the ESOF selector switch to 2High, your Transfer Case Motor is not moving the Shift Fork to get you back into 2 wheel drive. The Solenoid simply controls the vacuum to your IWEs.

 

Ok has any one run into this problem my IWE are locked in due to there being no vacuum at the iwe, i have vacuum BEFORE the first check valve after the ck valve NO vacuum, i have checked the valves and they seem to be working. Does anyone know if there is a vacuum tee at the back of the intake manifold.HELP!!!!!

 

If vacuum is present on the engine side of a check valve but not also simultaneously present on the IWE solenoid side, then the check valve is either completely clogged or installed backwards. There should be no check valves between the solenoid and IWEs.

http://www.f150forum.com/f72/how-dia...72/?styleid=14

Sent from my XT1080 using IB AutoGroup