High Pitched Noise, Engine Off
 

I don't think I've seen this one on here yet...

I had the car in the garage and turned the key to "ON" (but the engine wasn't running) and heard this high pitched noise coming from the engine bay. I opened up the hood and tried to bring my phone to the source. The pitch randomly changes and almost sounds strained at times. I thought maybe it was the fan for the radio/head unit, but it doesn't quite sound like it.

Thoughts?

I have ~950 miles

https://www.dropbox.com/s/hauyryk6kj...214_162428.mp4

Fuel pump priming?

That kind of what I thought...but it sounded so strained and inconsistent.

Do you have HIDs installed?

Edit: After watching the video, it does not really sound like HID ballasts. Sorry man.

Negative. Stock everything.

Sounds like the electric motor in the throttle body, it holds the valve open during start up to idle high and get the catalytic converters lit off, normally with you in the car and hood down it blends in with the rest of the car preparing to start (power steering, power brakes, fuel pump etc.)

I can't access the file at work, but it's most likely what strat said above. Subaru energizes their throttle motors anytime the key is on, and they are very noisy.

My car does this as well. I'm pretty sure I read it's a system check. Its the computer turning on checking the pumps and stuff.

That's my version of the story because I don't know shit about cars. I just know it's checking something and normal. I just can't remember what. :lol:

*EDIT*
Here's what BRZ's manual says:

Noise from under vehicle after turning off the engine

Approximately five hours after the engine is turned off, you may hear sound
coming from under the vehicle for several minutes. This is the sound of a fuel
evaporation leakage check and, it does not indicate a malfunction.

That's a different sound, it's very clear the sound from the manual is coming from the rear of the car around the gas tank area, as noted several hours after the vehicle is turned off. OP's noise is clearly originating from the engine bay BEFORE the car is turned on with the key turned to the second stop.

throttle body. normal

I only hear that when I leave the HIDs on after turning off the car (or turning them on without starting the engine). The high pitch sound goes away once I turn off the HIDs.