Bizarre hiss coming from the centre console

[Zhastaph]

I have this really bizarre hiss that's coming from around the centre console. It's the sort of noise that you get from speakers when a stereo is on but turned down.

What's even more bizarre is if push in the recirc button for the heating so that it takes air from the cabin then the noise stops then if I set it back to take air from outside then the noise starts again.

This is completely independant of whether the blower is on or not.

Something else, is that about 3 or 4 seconds after turning off the ignition it stops also

Does anyone have any thoughts on this?

Many thanks.

Col

[scoule]

Aren't most of the heater flaps etc controlled by vacuum? It sounds like you have a leaky pipe or actuator somewhere!

[Zhastaph]

Aren't most of the heater flaps etc controlled by vacuum? It sounds like you have a leaky pipe or actuator somewhere!

Hmmm, thankyou. If you're right then that would prolly explain why it stops a few seconds after the engine has stopped. Vacuum pipes seems a bit archaic to me but I'll dig the service notes out and have a look.