2.2L (Diesel) Oil leaking from camshaft emission valve

[Dusty roaches]

Hi all I have a ford ranger 2012 2.2 xlt and have a strange problem I can’t seem to find answers on, so on the camshaft case the emission valve seems to be leaking oil into the air pipes and then onto the floor. I started taking the air box off and Associated pipes and noticed oil inside them and traced it upto this component. Anybody have any ideas what’s the cause or resolve ? I have checked the Diaphragm and it’s intact no splits etc.