Has anyone ever cut open an oil seperator - breather box - to see what exactly it's made of, to help deduce how they can clog up and how to best clean them through? Is there a diaphram/filter or just channels to allow oil to pour back through return side?

I have recently been having some obvious crankcase pressure, with oil cap oil leak and rear main seal. Last checked the breather box had some 'chimney-like' effect when car was idling, so I assumed it was clear... all other PCV related hosing/nipples etc are clean.

So... what consitutes as a clear breather box, and was my deduction correct, or can I assume that partial clogging can be present causing some crankcase pressure? A few months back I did remove it, spray it down internally, nothing really came it, it blew very clean, but now I am not sure if maybe I should just replace it with a new one.

Note that in last weeks arctic weather of -45 degrees up here oil was fizzing out of oil cap... now in -25 no more, no major leaks. Could the EXTREME cold have solidified any oil sludge and caused this?

Advice anyone?

Thanks!
Greg Mustang
Montreal - Ottawa
Canada