Another IWE thread

[NorCal Offroad]

2019 Raptor - I read a few threads but haven’t found anyone actually manually applying vacuum to the IWE. First time I took the truck offroad it felt like it was pulling a lot to one side (I don’t remember which). I read this could be an IWE issue. I got busy and didn’t get back around to it. Lately I’ve heard an intermittent faint growling when coming to a stop, which I’ve also read could be an IWE issue. Replaced the check valve, no change, replaced the solenoid, no change. Got ahold of a vacuum pump and gauge today, I have zero vacuum post solenoid, but about 16in on the inlet side. Manually applied vacuum to the IWE feed, and held just fine, no leaks. HOWEVER - the axles still turn, even with manual vacuum applied (about 17in). Should the axles be turning in 2wd, with vacuum applied?

Also, replaced both fuses at said something about 4wd. Appreciate any input. Thanks!

 

[TomDirt]

This is useful

 

[NorCal Offroad]

This is useful

Did that. I have no vacuum in 2wd coming out of the brand new solenoid. I understand that for a couple miles it will remain disengaged, to warm up the front diff, however even when applying manual vacuum with the pump the front axles still turned. That’s where I’m stumped.

 

[rschap1]

You mention pulling vacuum and it holds, but still ask since it is so common; all the lines are ok?
If so, my next thought would be the IWE(s) themselves.

 

[NorCal Offroad]

You mention pulling vacuum and it holds, but still ask since it is so common; all the lines are ok?
If so, my next thought would be the IWE(s) themselves.

I’ve been unable to investigate beyond the vacuum test, but if it’s holding vacuum, I’d assume the lines are good.

 

[TomDirt]

If you have a mityvac and some 1/8" tubing you can check each IWE by listening for the click and rotating the tire (with the motor off). When they fail it's usually due to a tear in the diaphragm, not the steel spring, the gear teeth, or the aluminum housing.

 

[NorCal Offroad]

Should the solenoid be open, pulling vac, in 2wd?

 

[John813]

Think I have the same issue.
Grinding noise sound like metal being dragged under the truck?
Replaced the same items too. Of course when I dropped it off to Ford for this and another issue, no noise and they didn't want to investigate further

 

[NorCal Offroad]

I hesitate to call it grinding. More like growling from about 7mph to zero.

 

[TomDirt]

When my ecoboost had it I diagnosed it by driving in circles; the P-side line was torn enough to leak (and cause the groaning sound), while turning left at full lock, but not while turning right. I just left it in 4wd until I was able to replace the line.