4.0 question

[charlie268]

I have a 2000 ranger, 4x4, off road package and auto 5 speed overdrive. My question is I thought that the line that goes from the oil filler tube over to the air duct tube was a vent line to allow warm air into the air tube. I had mine running the other day and pulled the line off the air duct and it is a vaccum line. It sucked fast to my finger. If that is what it is for does it not suck air from the induction system?


Charlie

 

[Big Jim M]

It is there to take blowby from the engine and burn it in the cylinders.. It is called the PCV system. (Positive Crankcase Vent system)
Big JIm

 

[charlie268]

I thought that was on the other valve cover where the pcv valve is?

 

[Big Jim M]

Ok so you have the PCV that is sucking blowby and general smokey crap out of the engine. THAT hose is allowing clean, filtered air INTO the engine so the PCV can suck out the dirty air.. So in an engine that has little or NO blowby there will be a vac in that hose that is noticeable with your finger.
Big JIm

 

[charlie268]

Thank you