OK, I have a 06 5.4L 4x4. When I back up to the left, I get a popping noise. I'm thinking the IWE's aren't getting enough vacuum to completely disengage. But I've been working alot so I don't really have the time or energy to check vacuum, etc. I'm not sure the IWE solenoid is the problem, but it is not the new style with the rain hat. Should I just replace it? I don't want to just throw parts at it, but if it would be a good idea to replace it anyway, even as preventative maintenance, I will.

 

How are your ball joints? Mine would stick in place sometimes and when I turned usually sharper they would make a loud pop and sounds like something broke. I would change the silenoid out for the one with the hat just for future protection. It's a $30 part that can cause you a lot of trouble and money if it goes bad.

 

If your IWE actuators, one or the other weren't getting enough vacuum, you'd know about it. Either it'll start grinding driving, or it'll start grinding under load (driving up a hill, load, etc), not popping. At least with my experience.

As speterson wrote, I'd be checking balljoints, tierods, maybe CV's personally.

EDIT: *IF* you want to check if it's the IWE solenoid, you can unplug the vacuum lines at the actual solenoid under the hood. It takes seconds... If the popping is still there, it's not likely the solenoid or actuators. Pulling that vacuum line at the solenoid forces the hubs to stay engaged. I'm still not thinking it's IWE related though.

 

Thanks for the replies. I guess I'll have to do a little looking under there. I may replace the solenoid anyway, since it's not the new style. The weird thing is, if I back up to the left with the wheels turned 20 deg, it will have the popping noise. If I turn the same way 45 deg, the popping will be gone. If I turn 60 deg, it will pop again. And it's only when turning left backwards, coming from the right front wheel.

 

You get er fixed?

 

No, I've been busy with the Holidays. I need to look at it before it breaks down in 15 deg weather, though.

 

So I decided to replace the IWE solenoid, I needed the upgraded 1 anyway. I still had the popping noise, but it became more infrequent. I live on a dirt road and we received quite a bit of snow this year, making the road fairly slick from time to time. I used 4X4 frequently and I think with the extra engagement of 4WD, the system started working better and I haven't heard the popping noise for a while. I still think I had lower vacuum or the IWE on the right side was not disengaging properly. I live in Wisconsin, on a dirt road, so the combination of salt and mud might play a role in this situation.