Hi there, have you checked for any oil droplets on the road, this would give some indication of where to start looking. Also if it's burning oil it could be an oil feed to the turbo, depending on model. Or it's dumping a load of oil through the intercooler from the crankcase breather. Which builds up, causing the engine not to start straight away. Disconnect the hose from the throttle body and the intercooler and see how much sludge is visible. And like everyone else has recommended DON'T give it a good blasting. Hope this was helpful.