# name that sound



## OnlyTaurus (Mar 20, 2012)

Jaycruze said:


> I need to start making videos of this stuff, but anyway.
> 
> 
> If I pop the hood (keys are in my hand) I will sometimes hear a ringing sound coming from the engine bay.
> ...


Engine running? If so, A/c on? Need more details my friend.

Edit: Duh.. keys in your hand.. blonde moment.

So just from popping the hood the noise starts?


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## Jaycruze (Jul 11, 2011)

Ya, Only if pop the hood... I think anyway, The noise is very faint so I might not even hear it with the hood closed.

Car is completely off. It's like a really faint dial-tone sound but higher pitch.

I thought it might be whatever is powering the interior lights (since i opened the drivers door) but the sound comes back later when the lights are off.

Basically, I'll be standing there talking cars with my buddy after showing him my motor and I will hear this sound come and go while we are talking lol.


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## Bohdan (Apr 28, 2012)

The front hood has a switch that lets you know at the inner screen it is open perhaps something to do with it.


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## Dale_K (Jul 16, 2011)

Did you open the car's door to reach the hood release? A bunch of stuff seems to wake up when you open the door. You could try a little experiment and leave the hood open when you shut the car down and then come back a couple hours later and simply open the door while listening under the hood.


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## rubiconjp (Feb 10, 2012)

I also hear this high pitched noise from time to time. In other threads, some had also reported it. In my Eco, it's more reproducible if I was using Bluetooth or radio and turn off engine and get out. Bluetooth or radio sometimes keeps going and I would hear this high pitched sound.

Sent from my Galaxy Nexus using AutoGuide.Com Free App


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## rbtec (Feb 3, 2012)

Some kind of pump.


Sent from my Autoguide iPhone app


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## saj1jr (Jul 16, 2012)

I too have heard this sound and wondered what it could be.


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## AutumnCruzeRS (Sep 10, 2012)

Is this the electronic thermostat we are hearing?


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## NYCruze2012 (Jan 16, 2012)

I hear it sometimes but not always on my 2012 Eco.

Sent from my Telefunken U47 Electronic Response Unit


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## Aussie SRi-V (Aug 25, 2012)

TCM Solenoid


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## brian v (Dec 25, 2011)

Took an aussie to guess this one I also wondered what this humming sound was and where it was coming from . Good call bro


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## Aussie SRi-V (Aug 25, 2012)

After listening to this sound for the last 12 months, and not finding an answer here,I had to spend an hour or so, on the hunt for it.
I was not going to come away without finding the component making this intermittent buzz. 
I still have the WHY question in my head, but at least I know what and where...


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