Hi Nigel, Just joined this forum.I've had these symptoms on other cars and a large passenger carrying vehicle(bus)with engine oil being drawn through a worn turbo shaft. As you say its quite scary but even scarier when you havnt cleaned out the residual oil in the cooler after you have changed the turbo. I dont know if the fault codes are a distraction but its worth a quick look at the turbo shaft or for excess oil passover. Regards Ian