The turbo on my 2.8 Movano destroyed itself a couple of weeks ago, google "runaway diesel" turbo was sucking up the oil up out of the sump and running at full revs on it belching grey smoke covering both sides of the road, so then obviously the engine dosent stop when you take the key out, managed to stall it before all the engine oil was burnt saving the engine.
My turbo had started to whine a couple of weeks earlier so investigate the reason why if yours starts to do the same.
Anyway, I replaced turbo and bought a new intercooler as it may have been full of the missing turbine blades, it runs fine now - very lucky.