I have a1990 F350 with 460 and would like to know the function of the hose going from the neck of where the oil goes to the airbox. when replacing the air filter I noticed a little oil in my airbox. Is this normal or do I need to replace anything??

 

A little oil is normal. It's part of the crankcase ventilation system, the vapors get sucked into the intake and burned as opposed to letting them escape into the air.

 

Install a oil catch can if your worried about the vapors

 

check/change the pcv valve-that hose should be the filtered air going into the motor -probably on the drivers side vavle cover right? the pcv valve is on the opposite one-as the motor pulls air in from the pcv valve it needs to pull air from that pipe-should be a special little air filter for it also -well there is on the smaller motors

 

Ok guys, thanks for that info !!

 

Also be sure to check to make sure you have vacuum on the hose going to the PCV. I have seen more than once the vacuum port coming off the intake plugged up with carbon.