I EAT HYBRIDS, i dont know for sure if the actuator is making that noise or not, i really want to say it is, cause thats what mine did when i had a leak in a fitting, when the RPMS got up and there was load on the truck, even slight load, the vacuum drops and the IWEs try to engage. And thats what i saw and heard there. You might want to get a guage and a long peice of vacuum line and a T and tap into the vacuum line and run the loing line into the cab through the window and hook the guage to it. Then while your driving down the road watch the guage, you will see it drop when the RPMs gain (if there is a leak) and if it drops far enough, to the point where you hit 5 (whatever unit of measurement) that should be the exact time you start to hear that noise. If that all happens you need to check the actuators with the guage, the lines and the check valves. Read up on the original instructions i gave for testing.

i will try to take some pics, but its stormin like crazy here today and im not gonna stand in a storm to take some pictures, sorry, ill try to get them though, the vacuum coming off the intake is on the passenger side and runs to the solenoid that is mounted on the fire wall behind the battery. Halfway between that solenoid and the intake is a check valve, check that check valve and see if its still good (suck on it, you will be able to suck on one side but not the other) if you can suck on both sides, even if really easy on one side and just a little on the other, replace it, even a little vacuum let back to the intake can take enough out of the system to let it try to engage.

Hope that helped.

 

thanks and let me know when you get the pics! Also one more ques. Would engagin /disengagin 4wd be any diff with a leak? My 4wd engages right away but when you disengage it, it can take literally a min or two. Also if i engaged 4wd, would the whine go away? just lookin for another way to dignose the prob until you can get pics. One more ques, am i hurtin the truck with this whine and could this vaccum look also cause the hesitation i feel with the motor when i floor it on the hw?

 

Wine should go away when you engage 4WD because you are taking the vacuum away and the actuators are completry engageing and the gears arent trying to partial mesh at high speeds because of partial or low vacuum (your leak).

4WD should engage fine also because you are doing what the leak is trying to do, engageing the hubs.

You could be hurting the gear on the end of the cv shaft that engages with the actuator, because that is what your whine is the gear on the end of your cv shaft and the gear in the IWE actuator trying to mesh at high speed.

It will take some time with a vacuum leak for the 4WD to disengage, because its like trying to blow up a balloon with a hole in it. Its going to take some time to get enough air into the balloon and fast enough to compensate for what your loosing out the hole, get it?

You need to get a vacuum guage and start testing each component in the vacuum system to see what is actually leaking,(actuator, lines, reseviour box, bad check valve) There are instructions in the article i wrote, it will really help you understand how the system works.

But in the mean time what you can do to prevent further damage to the gears, unplug the line coming off the intake, or at one of the connectors in that line and plug it off on the engine side of the line, this will release vacuum from the IWE system to the actuators, they will engage and not grind, your half shafts will turn while your driving but you will not be in 4WD, this is perfectly safe (I unknowingly did it for over 6 months before i relized i had a massive leak) but make sure you plug off the line coming off the intake so its not sucking air into the intake. Good Luck

 

Ok thanks! Will this vaccum leak also make the eng hesitate when i floor it? Cause it does that to. But it seems like every syptom youv listed, my truck does. About your article, is it in the first post/first page of this thread? Or is their a seperate link? Thanks again for your help and pm me when you get your pics.

 

Yes, everything you need should be in that first post, if you have questions about, just ask. Im not sure if your hesitation is linked, but it could be possible because if you have a leak, then the engine is sucking in more air through the vacuum line for the IWE system. Just a thought, im not sure of it though, so the first thing i would take care of is the IWE system problem and see if the hesitation disappears.

 

ok thanks! Well, i tryed somthings on the way to the gym today. Engaged/Disengaged 4hi and drove on a straight road. Still whines. Did the thing with 4l and it still has a whine. So its not a IWE prob. It has to be a pulley. Maybe the idler pulley? Heard alot of F150 owners on F150online.com havin idler pulley whines. Now i gotta figure how to test that. Also since it aint the IWE, that elminates the vaccum leak causin the hesitation. Now i have to fig that one out to lol

 

Ya look into the idler pulley and the alternator. Last year when it got cold my alternator started whining and I replaced it. I guess that was a common problem too. Well look at the bright side you don't have to pull the front end apart to replace a IWE.

 

haha ya i know. I know the alt aint bad because the lights aint dimmin. Ulnless the bearing on it is bad. 4

 

Well mine wasnt "bad" in a sense that it was charging fine. But the bearings or something inside would whine and the pitch of the whine would change with the RPMs. i guess I should have been more clear, the alternator isnt bad, it just whines. Check it out.

 

Ok that makes sense. Thanks ill check that out and get back to you. Thanks again for the help!

 

No problem

 

Well I got my 4x4 fixed Friday, they had to put an actuator in it ,said it was the first one they had seen act like mine ,they said it usally makes noise in 2wd not when you put it in 4wd. But any how it is fixed..

 

The acutator could have been gunked up or something like that and when you engaged the 4WD and the vacuum was released all that gunk was keeping the actuator from fully engaging and letting it grind because it couldnt fully engage. Thats the only thing i can think of and sounds very plausible.

 

Hello XJCamaro89...it really sounds like you have this problem figured out. Perhaps you can offer me some advice? I have what seems to be this problem. My Ford (04 F150 Supercrew, ith 101k miles) will not go into 4L. It seems to go into 4H ok. In 4L, the dash light comes on but no traction. Also, it seems to have the same "growling" "humming" sound, seemingly coming from the front passenger side, at speed (25-45 mph) in 2wd. From these symptoms, can you offer some advice?

Thank you very much in advance for your help.

John

 

JWT, Im not sure why your 4LO would not be kicking in if the light is on. And you 4HI works fine. Maybe some others can chime in.

As for the growling from the pass. side. It could be one of three things, and without testing i cant tell you one for sure. Either the IWE solenoid on the firewall isnt working properly. The passenger IWE actuator is bad. Or you have a leak in one of your IWE vacuum lines. Read through my first post on the first page of this thread. You willl find information on all of this to get you started.