intake noise when hot

when my 4L ford engine gets hot, a low "moaning" sound comes from the intake especially at idle. sometimes i can hit the gas and lift off and the sound goes away. this seems to happen only during hot summer or while pulling a trailer. i have pulled the intake system up to the manifold and the sound is in the engine somewhere. anyone else have this on a 4L or have an idea as to where this sound is coming from?

Likely the IAC on the side of the throttle body. Try cleaning it with some carb spray. If it has a black plastic cap on the side of it, pop off top cap and clean felt pellet. Please include the year, these aren't Volkswagons that never change.

forgot to include the year. 1996 explorer, 4L engine, 4x4

I also have this noise and have been told that it may be related to the composite intakes. Did you try the fix that was posted to you and did it work. With out removing the intake and not finding a intake leak yet I'm at a loss. I have heard from other explorer owners that tis is a common problem

i haven't done anything yet. not sure what the IAC is or was so i left it alone. i still have the noise. guess i will just turn up the radio!!! thanks for the reply.

i haven't done anything yet. not sure what the IAC is or was so i left it alone. i still have the noise. guess i will just turn up the radio!!! thanks for the reply.

hoot49,

The IAC is the Idle Air Control valve. It is an electrically-operated bypass valve in Ford EFI engines that regulates engine idle speed.

Cheers!

thanks gravesubject. will this thing moan? the idle speed seems unaffected while the sound is coming from the engine.

hoot49,

I don't know if this would cause any moaning noises, but it would change your idle speed, which could cause some funny noises... My wife's Taurus (1995) once had the IAC jammed open by some debris (after a knucklehead at an oil change place failed to reconnect the intake duct to the air filter housing) and the car roared like a jet plane regardless of the throttle position. Try cleaning it out, it worked for me.

Here's a related thread:

http://www.automotiveforums.com/vbulletin/showthread.php?t=78748

Good luck