Noise from passenger side when driving

[Pip]

So I have this weird sound. It is barely audible and only happens when in gear driving with foot on gas - starts around 2k RPM.

The sound comes from the passenger side near the engine bay from inside the car and sounds like either metal pieces sliding in each other or air hissing through a pipe/hose. Nothing at idle and nothing while driving with foot off gas.

Any ideas - wish I had a go pro to help out with the sound. I could just be super paranoid because all windows must be shut and radio/AC on low to hear the sound.

[Oli77]

Does sound change pitch or intensity with higher rmps? Pulley?

[Dave1027]

Does the sound go away when you turn the ac/heater fan off? Two possibilities, the fan or air in the heater core?

[SoCalZman]

Can you get an iPhone video of the noise?

[Pip]

Ok I'll work on the video. I found out it is actually coming from the intake side of the engine bay and might actually be associated with the new AFE CAI I just installed. It only makes the sound when I barely have the throttle pressed and it goes away if I release or press throttle harder. I could try and replace with the old air box.

[2004_blue_zhp]

This sounds a bit like the lower intake boot whistle. I had this issue last year. A small crack in the lower intake boot makes a whistling noise when under light throttle (in gear). Just like what you describe, for me there was no noise at idle or with heavy throttle. Replacing the boot (which did indeed have a big crack in it) fixed the issue for me. Could this be what you're dealing with?

[Pip]

Maybe. Prob needs replacing soon anyways. You are pretty much describing my exact issue. Ill take a look at the boots.