I finally replaced my Pcv valve after 10 years (I have a duratec, if you've ever replaced one on this engine you can understand why I waited so long... ) Anyway it was obviously toast and alot of oil poured out of the intake hose. Just curious if all the oil being sucked into the intake over the years would require some sort of extra maintenance or cleaning or should I just not worry about it since the engine is running fine.

 

The oil is from oil vapor condensing on/in the PCV Valve

The oil vapor in an engine comes from the Blow-by when a cylinder fires
The walls of the cylinders and sides of the pistons below the rings have a coating of oil.
When a cylinder fires some of the very hot explosive gases will "blow-by" the rings and vaporize some of that oil coating.

Bearings and valve train oil creates a mist, which doesn't travel far, just FYI, so not part of the oil vapor

In the old days the Blow-by(the gases) and the oil vapor when out a vent in the lower engine or upper oil pan
So constant drip of oil from that vent.

PCV system was added to clean up that mess.
The Blow-by and oil vapor are pulled into the intake to be burned in the cylinders.

PCV Valve should be cleaned every year, replaced every 2 years.

Yes the 2.3l Duratec PCV Valve location is................a pain in the a$$ to work with

You could pull intake and clean it but that would be the only way to do it, nothing can be added to clean it up

 

Ron, any chance my obviously stuck open pcv valve added to my fuel mileage issues. I know we diagnosed the odometer issue. But just curious if a bad pcv system can hurt fuel mileage.

 

Yes, for sure, if you were sucking in liquid oil now and then it would cause you to have to push down on gas pedal more for same power.


It can also cause oil leaks in valve covers and oil pans
Blow-by creates a positive pressure in a sealed engine, working PCV system changes it to a negative pressure, preventing the start of oil leaks