Oil coming from blowby hose

[480sx]

Hey guys, I have just recently noticed that occasionaly there is oil coming from my blowby hose. the hose that comes from the bottom of the block that has a t fitting into the valve cover, i used to have a small filter on there but when i took it off I noticed it squirting oil onto my header. Is there a one way valve or anything that might be clogged or broken?TIA