My 4.6 has been making a wierd noise and its sounds like a humming. The humming went away when i gave it gas or was running at any rpm abouv idle. Hence why i went strieght to the idle air bypass. I found it was making the noise s oi pulled it off. It looked real dirty and all crudded up. Is there a way to clean it up or do i just have to bite the bullet and go buy one for $70. Somebody online was disscribing a filter in the back after you took of the sensor. How do you get it apart?

 

What r u talking about? The IAC ?



You take the TB & elbow off.

 

Thats exacttly what i was talking about. What would you recomend for cleaning it. Carb cleaner???? Should i just spray it in there. I wont ruin the sensor

 

I use "Deep-Creep" made by Sea-foam, it cleans and lubes at the same time.

If it's real bad - use brake cleaner(or carb cleaner) and compressed air (shot of B-Fluid -then blow that crap out of there) first , then Deep-creep or WD40

Move the components by hand(small pair of needle-nose) to free them up good.

Look closely for any deposits on the rod itself (usually black) - try to get those without scoring the rod and she'll idle smooth - reboot the PCM after(You should have the neg. off anyway before performing this procedure)

If the "Rod" is too f'ed up (pitted) or other , you need to replace. I still have my stocker- has 206,000 on it lol..

Another note: I don't use gaskets on anything above the lower intake - gaskets leaked(even new ones, on mine), I checked w/propane. I now use "Permatex RTV High heat silicon" Black, cures faster and no leaks.

 

i need to clean mine again. i used electric parts cleaner and it did an ok job. Sounds like something to do tomorrow.

 

So I need to take the TB off to get to the IACV?

 

No, but take that off anyways to clean, also clean the elbow it bolts too. Throttle body cleaner works good, with a toothbrush. The IAC will work good probably till this time next year or two years but at least you'll know it works. After cleaning the truck may idle funny, wait for a bit it's normal. Mine would idle then raise a few rpms, say 150-200 then back down. I didn't disconnect the battery also so probably do that to avoid any issues. Keep in mind that cleaning just prolongs the enevidable, a new one costs around a hundred bucks or so (cheapest) I've heard about.

Oh ya, be careful taking the IAC bolts out and remember that there is a gasket, don't loose them, be careful.

 

I've clean the TB with TB cleaner. Had it working for a while before it started again. I then did a little more reserch and found out about the IAC. Went back in with some TB cleaner and was going to remove and clean the IAC. I must not know where the IAC is. I thought it was on the right hand side of the TB attached with two brass looking screws. I unpluged the wire from it and tried to turn the screws be couldn't get them to move. Started to strip the head of one so I stopped. You say that it has bolts. I know jbrew shows a pic of one off the TB already. Are there any more pics out there? Thanks for all your help! Trying to keep it away from the dealer $$$!: eek:

 

Only the 97 is on the side. I posted a pic of the 2000,(in the back) just 4 threads down from yours , here click on the link to see were yours is -

https://www.f150online.com/forums/sh...d.php?t=268079

 

Keith Hudson, the IAC on yours should be on the back of the throttle body elbow on an angle. It leaves just enough room for your hands between that and the firewall. Forgot to mention the plug too, that you can unplug later if not before IAC removal. The bolts I mentioned are really tiny, like an 7-8mm head and that's it. Once you see it, pretty much the most northern thing on the engine, you'll be like "oh yeah". I can't remember, but this is based on a 5.4L, not sure what you had again, 4.6 ought to be similar and 4.2 is close to the front. All IAC's look about the same so it should be easy to locate.

 

5.4 / I finally found it! I was way off! Thank-you!!!

 

Heres a better pic of it - this is an 01 5.4L - Funny OASIS shows my 98 on the side , but it's not - mines in the back as well.. Like this one. -

 

Just replace it. Once it gets that bad, it'll come back again and again./.....I know from experience. It used to happen on my 95 explorer and it irritated the helloutta me. A new one permantly fixes it, while cleaning leaves it open to reappear at unappealing times.

 

One note about WD40, it's a great for displacing water and cleaning, but not for lubricating. If you clean with it, make sure you follow it with something else to clean out the WD40 since it does gum up under certain conditions.

 

LOL - WD40 don't last long enough to gum up - work great for loosing up the components , I blow it out with air , it does two things - frees everthing up and when you put the air to it it forces lube into areas you can't reach - been doin it for 206,000 miles ..Just common sense needs to be used , like dialing down the pressure.