Buzzing noise at idle

[pumpkinbrat]

Hi everyone
I have noticed within the last month or so that my explorer makes a buzzing noise when it has been at idle. Sometimes I notice it when I am in stop and go traffic and other times I notice just when I am sitting in a parking lot or something and in park. It is so loud that I can hear it over the radio. If anyone has any clue what this noise is and how I can fix it, please help me.
Thanks everyone!

 

[Bashman]

If it sounds like it is coming from under the hood it is probably your IAC valve. If that is the case it just needs cleaning.

 

[pumpkinbrat]

can you explain a little more what the IAC valve is, and where it is located? Thanks in advance.

 

[borderchris]

hey there. First off, it could be a myriad of things, if it is your Idle Air Control (IAC) valve, it is a silver cylinder laying sideways, about the size of a salt shaker, mounted on top of your throttle body, directly next to where the throttle cable inputs. It makes minute adjustments to the idle based on all kinds of stuff, like temperature, air density, etc.

I personally would have a friend sit in the X, put it in drive, hold a foot on the brake and STANDING TO THE SIDE OF THE HOOD (now popped, by the way...) listen for various offending sounds. Often it's just a loose screw on a cable clip, or a shield bolt. Does the sound go away when the vehicle is revved? Could be the IAC. No? Probably a stationary loose part.

 

[pumpkinbrat]

Thanks for the advice. I will check it tomorrow and let yall know what it is.

 

[Opera House]

Get under the vehicle when it is cool and tap on the heat shields. They are attached with a little band that snaps. Good news is that a large stainless hose clamp (think 2 1/2 inch) works well to reattach them. Just open it up and slip it over. I've had to do it on two shields.