I have been doing some reading and I think I may have a problem with the IAC. My 5.4 has 132,00 miles on it. The idle is pretty good but there is an audible "hoot" at around 45 mph when rapidly releasing the throttle from a partial throttle condition.

Does that sound like the IAC? Would it be best to clean it or just replace it?

Mike

 

Sounds like you got it. I suggest to replace the IAC only with Motorcraft parts.

 

I would try cleaning it first. That may be all it really needs. I just use WD-40 when I clean mine.

 

You could clean it, wait a few thousand miles and clean it again, and again, and again, or you could just replace it. Its a relatively cheap sensor with a two bolt install.

 

Dang!!!! I knew I should have bought a new truck when mine got dirty last week. I will know better next time huh.

 

I think I need to replace mine. 70 bucks

 

Well, this would be true, if realatively cheap meant 50$.

Now, if it were not idling at all, yes, a replacement would make sense. But hey, thats just me.

Some of us don't have deep pockets.

 

Eventually, even cleaning won't work. This went on with my truck for about a year. I kept cleaning it and finally even cleaning it wouldn't work. The sound was sooooooo annoying that I had to buy a new one from Ford for about $65.

 

Well, when you run a liquid intercooled blown 5.4 a $50 part isn't one you want ruining your day. Come on, a typical oil change these days is $30. Just don't buy 10 packs of marlboro's and you've got your sensor.