Meanwhile I found ot that the oil separator the car came with only has two hoses, one is inlet from the rocker cover (Red arrow) and other is outlet to the air filter (Green arrow).



Now, the standard Ford one has also a third one that as far as I can tell also features a one way valve and runs to vacuum behind the engine. Is that correct? Could that be the cause of the oil spitting??

EDIT: Oh and also there seems to be a corner of the turbo duct support bracket missing as you can see in this pic. Not sure if it could be leaking there from the rocker cover?