I'm hoping someone has had this problem and can help me out as its driving me nuts!!

i have a vectra c 2006 1.9cdti 120
it has become a pig to start mainly from cold but getting progressively worse, also it seems to be dumping oil on start up, like a single burst but then not continuously leaking.
we have plugged in to ethos and no faults are showing. i have heard rumours of some kind of breather that gets blocked or possibly broken that would cause the oil leak and also the engine to lose crank case pressure so therefore make starting an issue too.
has anyone came accross the same problem? or have any ideas to help me????
any help would be gratefully recieved.

regards tom