oil blowback into carb?

ok. so ever since i've had my truck i've always gotten really bad oil blowback into my carb. i just had my weber put on and still have it. so what can i do to fix it? the oil is getting my air filter really dirty, really fast. and i've seen pics of other people with webers that have like a mini air filter on top of their valve cover, what are those, and would it help? thanks

bump, any help?

on a stock set-up, a hose comes from the valve cover into the stock air cleaner which has a small filter in it.That hose trps oil fumes and recirculates them . When u run a Weber as I do, and many others on here, U need to put a small self contained filter in the valve cover to trap those fumes.u can gettum at any parts store.I dont understand where u are getting "blowby" into a Weber.The PCV valve hose should be going into the base of the Weber and there is nothing else to get blowby from.????BJ

When combustion pressure gets past the rings, it goes into the sump.

From there, it has to vent somewhere.

The PCV is designed to create a negative pressure inside of the sump, evacuating the fumes.

If that system is insufficient due to worn out rings / aligned ring gaps, or other factors, then the vent on the top of the valve cover allows the excess pressure out . .but it isn't really desinged for that purpose.

The PCV is supposed to draw clean air IN to the vent via the air cleaner.

thanks for the help guys. i got one of the breather filters to go on top of the weber. and i was getting "blowby" into the weber because the mechanic that put the weber on, hooked that hose that went to the stock aircleaner back into the weber, along with also hooking the weber back to the emissions system.