Fabia Tdi makes buzzing sound for a few seconds after engine is cut

[Paul]

a '56 1.9 Tdi to be precise - it is coming from under the bonnet, from a black box mounted on the bulkhead, on the extreme o/s, and it has five or six rubber pipes coming fom it.

Can someone identify this box please? And why might it continue to buzz? The car appears to run normally.

Thanks.

[F Murtz]

It is where the bees live.

[dom]

Presumably something to do with keeping oil/coolant circulating after the engine is turned off. Lots of modern cars do this.

[Chris Bartram]

It's a vacuum control box.

[Bob Minchin]

My diesel Cmax makes similar noises. One source I have read is that the EGR is excercised a for a few cycles whilst it is warm to reduce the risk of it sticking after cooling down.

Bob

[Paul]

ing from under the bonnet, from

Many thanks - what does it do please? Or rather, what devices does it control the vacuum to, and why would it worry after the engine is switched off anyway?