k, my truck started making this noise a couple of months ago. but it is very intermintent. it usually happens when i am idling at a light. it first started out only doing it maybe once a week but know it happens almost every time i drive my truck. it is a very loud humming and i can hear it clearly in the cab of the truck. i popped the hood one time when it was making the noise and i put my ear to my intake filter and it is coming from my filter. Does anyone know what this could be?? Ive got a 97 F150 with a 4.6 and the intake i have is an air force one intake.

 

my old engine did that, I opened my tb up just a little and reset the tps to .99 and it quit.

 

If you removed the IAC intake muffler (4.6L were the box type) chances are that's where it's coming from.

 

What's "IAC intake muffler"?

"my old engine did that, I opened my tb up just a little and reset the tps to .99 and it quit." English Please..

My 2001 4.6L with a K&N FIPK makes the same Humming noise when idling at a light. If I give it a bit of gas, the sound goes away.

 

this is caused by the Idle Air Control (IAC) Valve. It is connected by a tube from your intake pipe to the manifold. A new one can be purchased for about $50. check out this thread. https://www.f150online.com/forums/sh...=IAC+valve+4.6

 

It's a plastic muffler that's in the IAC air inlet line just before the IAC. It's meant to keep your IAC quiet. The 5.4L's have a round one. SOME 4.6L's have the square type.
People will illiminate these when they purchase an aftermarket intake then wonder why it makes humming noises. - That's why...

That's perfect English, you just don't understand it and it's been explained many times over and over again in these forums. Use the "search" feature.

Type in "TPS adjustment" - It should read .99 on the meter -or lower in the "key on" position.

 

Yeah don't remove the plastic box thats connected to the IAC, its a terrible noise! If you have good hearing, you can put your ear up to the intake filter and when the IAC operates you can still hear the hum buts its almost indetectable.

 

what is this has already been tossed? Is there a workaround?

I have already purchased a new IAC Valve and was preparing to install it this weekend to resolve the excact same issue as OP.