I have a 2005 325xi, and was wondering if anyone knows the source of a whir/click that comes from the rear area of the car when starting or stopping the engine.
It happens about 3-4 seconds after starting the car, and the same noise is also heard about 3-4 seconds after turning the ignition off. The noise is only audible from outside the car (can't hear it if sitting inside) and it sounds like it's coming from the vicinity of the rear wheel on the driver's side. It almost sounds like a small electric motor running for about a half second.
Anyone else heard this noise? Could this be something related to emissions control?