I know about the ticking noise coming from the IACV when the engine is idling. However, I just noticed something totally different when I put the ignition key to ON then OFF while the hood was open. I heared this loud whirring noise coming from the IACV whenever I turn the ignition key to ON or OFF. The noise isn't that audible while the hood is closed which is why I didn't notice this sound until today when I was doing my weekly engine check and decided to reset the ECU. The duration of the sound is short, probably 1 or 2 seconds. And it is present regardless of whether the engine is cold or warmed up. What can this be?? Anyone know what I'm talking about?

i think i hear the same noise.. its loud when i turn the key too. except i can hear it in the car and when i drive...

totally normal

I recorded the sound using my cell phone but there's no way for me to send it to my computer via email. I will probably use my digital video recorder and try to record the sound tomorrow. I'll post it here.

i had the same problem about 2 weeks ago, it was my iac ficd
(intake air chamber-fast idle control device) mine made a horrible vacuum leak sound and clicking when i turned the steering wheel. replaced and voila
hope this helps