Here are my latest findings on the source of the sound.

Click Here.

 

Sorry to bring up an old thread,

but, I now have this sound, well just noticed it, a week ago..and if it is true that is was there all the time, then it has gotten louder over the past week, cause I never heard it..now it is totaly loud...

My car now does it at any temp..(I have a stock airbox with a duct.)

Anybody figure out how to fix this humming sound?

 

[QUOTE]Originally posted by Roku_F20C

 

no seriously, mine has gotten really loud, and it's like there is a friggen midget with a kazoo in my intakebox....

you can actually now feel it on the air duct that I have....I know it was not this loud before...

 

In a sense, I wasn't kidding. Read further:
If you go to the provided by Hyper-X, you'll see the explanation for this humming noise. It is possible that yours has gotten louder for a variety of reasons that may NOT be normal. The idle air control mechanism may be in need of attention. This is not to say that it is malfunctioning but rather, it may not be operating at peak efficiency. There have been several reported cases of this system acting up, causing an intolerable noise that was only alleviated by replacement of the idle air control solenoid/valve. We also know that our cars intake from the throttle body on in, gets really oily and filthy from the input of oil from the PCV. A thorough cleaning may also help to clean out the idle air control system and make it operate better. A good "carb" cleaner spray into the throttle body might prove useful. Just make sure the cleaner is safe for our cars' systems.

 

Im having the sam problem stock airbox and filter, with the wall removed. also getting the p0411 error