Whistle At Low Speed

[BobbyPosh]

Can anybody tell me what this is? Toyota main dealer and local garage do not know. At a speed of 30mph or less, usually at the end of the day, after quite a lot of driving I get an electronic whistle in my 2002 1.8 Avensis Auto hatchback.

It seems related to the brake because it stops as soon as I touch the brake and returns when I take my foot off the brake. Often it starts when I go round a slow corner and it will disappear again for no known reason. Sometimes I can vary the pitch of the whistle by gently varying the pressure on the brake, almost play a tune! Sometimes it will continue a bit (quietly) even when I am stationary.

It is annoying if it just will not go away but usually it does after 20 minutes or so. The brake's efficiency is not affected , although I am a little concerned that something could be going wrong in the brakes that could prove significant. Servo? Trapped air? But it is an electronic sound, not a release of air pressure.

[Big Kev]

Can anybody tell me what this is? Toyota main dealer and local garage do not know. At a speed of 30mph or less, usually at the end of the day, after quite a lot of driving I get an electronic whistle in my 2002 1.8 Avensis Auto hatchback.

It seems related to the brake because it stops as soon as I touch the brake and returns when I take my foot off the brake. Often it starts when I go round a slow corner and it will disappear again for no known reason. Sometimes I can vary the pitch of the whistle by gently varying the pressure on the brake, almost play a tune! Sometimes it will continue a bit (quietly) even when I am stationary.

It is annoying if it just will not go away but usually it does after 20 minutes or so. The brake's efficiency is not affected , although I am a little concerned that something could be going wrong in the brakes that could prove significant. Servo? Trapped air? But it is an electronic sound, not a release of air pressure.

Contrary to your thinking it's an "electronic" sound, Bobby, it more than likely is the tiniest of slits/holes in a vacuum pipe allied to your brake servo. This further endorsed by the fact you can play tunes using the brake pedal.(Toyota stereo system THAT bad.....?) Had exactly same thing on a Ford years ago, and took me ages to trace it was a cracked hose.

Big Kev

[BobbyPosh]

Thanks a lot, Kev, I think you are right. Hopefully it will be a pipe and not the servo itself. The servo seems to be working fine so probably it is a pipe. I must see to it. I don't like brake problems. Bob

[kcummins]

i could be well off the mark but i heard when a turbo is going it gives a squeaking,whistling noises at low revs which may explain the reason it stops when you hit the brake.god is good im completely wrong and it is not on the way out!