It sounds like gummed up piston rings. Get a leak down test done.
Do you run on veg?
Gummed up rings won't make it over rev and refuse to stop. The turbo running on it's own engine oil will. deffo turbo oil seal gone.
it could be very worn bores, mine got a blockage in the oilways and wore its self out in no timeYes it can, it runs on the oil vapour getting up past the rings. It is not as dramatic as the turbo seals but still not good.
The pressurized crank case and the fact it lasted long enough to post the question point to the rings.
It can often start gradualy with the first signs being a bit over overrun when you switch off