I was driving my '07 w/ 360 miles on the odometer home tonight, and I heard such a racket coming from under the truck. Sounded like a wad of tin cans had wrapped around the driveshaft. It started as a real brief noise, thought I ran over something at first. Slowing down would shut it up, but then accelerating again would start the noise again for brief moments. I couldn't think what the heck it was and didn't have a light to get out and inspect anything. It finally progressed to the point of clattering so hard I could feel it in the floor which made me wonder if it was even going to make it home.

Pulled over, crawled under the truck, felt both drive shafts were tight, got back in, started back down the road, and it finally hit me: "Duh, it's the IWE's like I've read about on the FTE forum". Good 'ol forum.

Popped it into 4 HI for a few seconds, dropped it back to 2 HI and the clatter was gone for the remaining 12 miles home.

So, I've probably got a sticky, pos vacuum solenoid that will never replicate the problem for a dealer and some semi-shredded IWE's. How did I get so lucky?

 

I am having the exact same problem with my 06 F150! Any suggestions? Thanks Room 307

 

Consistently or intermittent?

If it's consistent, you've got a vacuum leak in the IWE circuit somewhere. If it's intermittent, and you can't get it to do it for the dealer, I'm guessing you (we) either need to sweet talk the dealer into changing the IWE vacuum solenoid (not likely the way Ford holds warranty over their head these days) or plan on changing the stupid thing on your own dime.

It would be nice to know whether the solenoid could be un-stickified with a shot of some sort of lubricant.

 

It is intermittent, and it gets nastier each time, which is maybe once every few days.
My concern now is not just the solenoid, but damage to the IWEs.
Everything I read points to IWEs, and I found the TSB on it, but I dread the games with the service dept. Been there, done that.

 

VFRman, have you had rain latley where you are? I'm willing to bet your solenoid is shorting out. It's located right behind your battery on the firewall. I had it happen to mine, and dealer replaced it.......I got home(it was raining) and opened the hood.....and watched the water rolling off the cowl right on top of the solenoid!! So I took a piece of sheet metal and made a cover for it....no prob's since june 06!!Get it checked out, as water can get ingested into the vacuum system and ruin the IWE's

 

My 04 had the same problem last Fall. Started in the rainy part of the year and only got worse with time. Eventually had it replaced by the dealer(not covered under extended warrenty) for about $350 and change. ROBBERY. been good since then though. Good luck trying to sweet talk your dealer. Hope your better at it than me.(one tip. don't call your dealer a theif or crook. It didn't work well for me)

 

The 07 has a new bracket design for the IWE solenoid so if you have an 07 you better get to the dealer and find what is really the problem.

 

Yup, there's a revised part for it. Exactly like the piece 96F150 made. I've had more then one replaced so make sure you get the newer solenoid. I'll post up the new part number tomorrow.

 

I was installing some stealth bulbs in the front turn signals tonight and figured I'd try to find that IWE solenoid. Started poking around the passenger side front wheel, and lo and behold, the siamese'd vacuum line was rubbing on the inner wheel lip. Think that might cause a problem?!! Ha!!

Sure enough, the leak was bad enough that the IWE would engage if the line was just so and then seal up and disengage the IWE if the line was not just so.

The plastic clips that hold those lines suck and blow at the same time. Those lines will be getting some more strategically placed zip ties in the near future.

Others have posted about this happening in the past, but I had forgotten that until today, and I probably would have thought "no, not on a brand new truck" if I had remembered. Shows what I know.

Off to the dealer in the morning.

 

After reading this thread and having the same issue I was driving this morning and egaged/disengaged the 4wd. The sound was there no matter what. Any recommendations before I take it to the dealer and they tell me they can't reproduce the sound (which will be my luck).

 

Just for your own education, find and follow the siamese vacuum lines that drive the IWE's. They start at the solenoid on the firewall right behind the battery and work their way down to plug right into the top of the knuckle at the wheel. See if the lines have any holes/abrasions/issues.

You're sure it's not a rattling heat shield? I thought my racket may have been a heat shield at first until it got so bad the floor was vibrating.

 

On my truck I found that the flexible heat shield for the drivers side cat was rubbing on the front drive shaft. All I had to do was push it off the drive shaft.

 

Well, everything I have read here has been pretty accurate. Could be the IWE solenoid, but the heat shield was too close to the drive shaft. If it was the shield, wouldn't it be noisy all the time while I am moving? My noise comes and goes. I do have an appointment with the dealer, but I was curious.... thanks, guys

 

Kind of a semi-newbie question(haven't been on the board since beginning of '05)

What the heck is an IWE?

On edit: Never mind, I googled it! How reliable is this system? Didn't they have problems with this in the old Rangers?

 

Hey Guys, took the info I learned here about IWEs, including the TSB# and trouble code#, and drove my grinding f-150 into my local ford dealer service dept. I was very gentle about it. I explained the noise and let him give me his advice and suggestions.
Then I gave him the TSB# & trouble code # and asked if he might be kind enough to check that, too, just in case. He just called back, the trouble code did come up, and it will be repaired under warranty. You guys may have saved me hundreds of dollars.
So, thank you very much to all of you!!!!! Room307