My "d" did the very same thing.The whirring noise you hear is the fan cooling the anti-freeze.Noises like that are normal.
Originally Posted by zz6938
10-15 seconds after i stop the engine, it starts whinning and making these weird noises.
I never bothered to take it back to dealer to address the issue. Waiting for my service time to come up so they can address the issue.
The sound is like, a little fan constantly running somewhere inside a closed area right above the exhaust manifold or in the area where catalytic converter is located(if the diesel has one).
Currently: 2014 328d / Mineral Grey Metallic / Nav / Apps / Backup Camera
Formerly:2011 MB E350 Bluetec / Palladium Silver / Nav / Active Cruise / HarmonKardon Logic7
Formerly:2009 335d / Monaco Blue / Beige Leather / Nav / iDrive / Xenon / Sirius / HD Radio