Renault Trafic 2.0 dci 114HP - Very strange sound - is it DPF or turbine?

In Trafic 2.0 DCI with a mileage of about 420 thousand km, after starting a cold engine, after about 1-2 minutes a characteristic "additional" sound from under the chassis begins to be heard. As if something howled, it whistled and it is not the engine itself. After turning off the engine, you can still hear something spinning and slowing down until it finally goes out (sound a bit like a slowing airplane engine - it whistles less and stops). Since switching off the engine, something howls about 2 minutes and stops. With a warm engine, this is not at all.

I will add that you can feel and see a different smoke balloon under the chassis, a smell definitely different from diesel.

Could it be DPF burning or turbine?

I attach a video with sound where it can be heard well both when the engine is on and when the engine is turned off. (In the movie, I turn off the engine at 27 seconds and then listen for 2 minutes as something goes on and slowly slows down and goes out eventually)
ps computer shows error: Mixture composition sensor circuit. Well, but this does not explain this strange sound ...
[film: b499e1dad6] https://filmy.elektroda.pl/42_1506677689.mp4 [/ film: b499e1dad6] (new video !!!)

Disconnect the egr plug to exclude it. For me, after quenching in 1.5 also for 10s cynic egr. It used to be like this.

Maybe webasto?

This car has no webasto.
Vacuum valves? How to check?

No, it's not the valves. Take it to the Pi channel to hear what it is. in my opinion, however, webasto.

When you write webasto, do you mean engine heater as described here http://renault.auto.com.pl/forum/viewtopic.php?t=155685?

Webasto like nothing.

Parking heater, engine additional heater.

And is such a loud work of this additional heater (webasto) a standard or is it eligible for regeneration?

ps where is located in Trafic 2.0 dci?

Standard page. After all, you can't hear this engine in the cabin.

Ok so that would be:

Yes, this device (from your pictures) produces this characteristic sound - if it is installed and it works, it is a normal phenomenon as the air temperature drops below the one set by the manufacturer, e.g. from 7 ° C down.
So it will help reheat the coolant all autumn, winter and early spring - what is it manifesting except the noise? Increased fuel consumption if the car often does not travel on the route and moves mostly on short sections. In my sharan I disconnected the ankle from the zero error additional heat.

This sound is Webasto for heating coolant / heating.
The sound is normal and just enjoy it working.
I suspect it is a 9 passenger bus.
If it wasn't for additional heating with this engine at a temperature below -10 degrees Celsius forget about the heat inside. and reheating the engine over 50 ° C