Yaris 2000 model is making "fax sending" noises when engine is swithed off.

[Regi]

My Yaris 2000 model is making "fax sending" noises when engine is swithed off and even if it has been left on the driveway for days without being driven. The sound is high pitched and all neighbourhood can hear it. One way to shut it up is to disconnect the Battery everytime you park the car for the night. Anybody experienced anything like it? 

[stantheman1]

Is the noise emanating from the engine bay or from the inside of the car? Has the vehicle had any accessories fitted such as an alarm, sound system etc?

[flash22]

What engine ?? a idle control valve can make a high pitch whine, a weak Battery may be the cause

[Cyker]

It's making it when you switch it *off*???

Can you record it?? Never heard of anything like this!

It's common for them to make horrible squealing noises when running cold in winter (Usually due to the aux belt needing replacement), but never heard of any of them making a noise when it's switched *off*!!

Only thing I can think of is a leak in a vacuum hose (unlikely) or a dodgy aftermarket alarm as stantheman mentions...

 

[flash22]

It's an internal fault can cause the valve to make odd noises iirc the internals can crack and the motor either gets stuck or tries to constantly adjust a lot of cars do it, it's high-pitched, but beyond most people's hearing range