I've read thru a lot of the threads on here and noticed many people have experienced this. I have a 2004 ford f250 5.4 and ithe makes a Humming noise only at idle. I have checked the fan clutch. it seems to be good and does not spin freely. I was thinking maybe idle air control valve but the truck idles like normal and does not stall. the sound does go away when squeezing the air hose doing tokay the IAC but comes back as soon as you let off. can it still be the idle air control valve if idles fine and doesn't stall? thanks in advance

 

Too much tokay.

 

Sorry for the ignorance but what? lol

 

I think he was just pointing out your error.

"the sound does go away when squeezing the air hose doing tokay the IAC but comes back as soon as you let off."


it kinda does sound like the iac is your culprit. try pulling it off and cleaning it. or just replace it

 

did you figure out what the problem was?

 

My old 04 5.4L did the same thing from when I bought it in 2007 until I sold it last month. I, too, was told it was the IAC valve and to just take it off and spray it out with some cleaner. I did this, and it did not fix the noise. I was told it was harmless and I guess it must've been for me to put 207,000 miles on it without an issue.