just picked up a second f150 a couple days ago, I seen an awesome deal I could not pass on. I will pobably either give it some TLC and resell or sell my current one. Anyways its 1993 and the p.o. removed the hose that's going from the valve cover to the air box. The installed a small breather on the valve cover.

is the a problem? we do not have inspections here in my area.

Oh its a 4.9l engine.

 

that hose you are referring to is broke on mine, i will eventually replace it when i get to it.

 

No it won't hurt anything, just vents into the atmosphere.

 

I have a K&N High Flow air intake on my 90 5.0 and that hose always comes off..... I notice no difference in performance whether it is hooked up or not.

 

The only reason that hose goes to the airbox it to hide the dirty oily filter.

 

what filter are you taking about?

 

That pipe puts oily air thru the air filter, making the air filter dirty and oily.

 

That pipe actually keeps hazardous fumes out of the engine compartment caused by the amount of blowby not pulled into the intake from the pcv. The excess is pulled through the tube and the filter traps the oil particles in the filter this is why it gets oily, Newer engines will not get as bad as an older engine that has been worn in, as in the rings are a little looser, produces more blowby.

 

Suggest that line is the air inlet for the PCV system - whatever air the engine sucks in through the PCV valve is replaced by the air coming from this line.

IMO, needs to be filtered - after all, it is an opening into the motor, where dirt does nasty things. The older motors many times had only a screen. As was mentioned earlier, by having it in the filter box, any excess blowby as the motor gets older, gets picked up by the regular air intake.

 

There is a crossover hose from the back of one head to the other on my 1990 302. What I am beginning to think is that this is a ventilation system and when this hose is plugged up, the PCV valve no longer pulls vacuum from the blowby from both heads and this is a big reason why the drivers side head that is vented back to the air box by way of the filler tube blows right back into the Air Box along with the oil that kills the air filter off early.

This poor old pickup was driven for years without having the oil or filter changed. I am going to clean this vent pipe out and flush the motor out real good see if that stops the oil leaking out of the air box.