j

just took the air cleaner off my 3.0 and found quite abit of oil in the bottom chamber. not sure whats going on.

jason191918

Could be blow by, thus letting oil into intake as well as pressure.

Matt16

Its often pretty dirty behind the plenum. Have you ever rolled the truck? When upside-down, oil can gravity drain into the intake. Check your PCV valve, see if it rattles, if not, it could be stuck open.

abecedarian

if the PCV valve is plugged, it's possible for blowby to find it's way into the air cleaner area

j

Maybe i don't understand its function right but aren't blowby gases unburnt fuel not oil. Doesn't the PCV valve put fuel back into the system?

scuba

im at a loss,
but you could always read this and get a good understanding of what it does
http://en.wikipedia.org/wiki/PCV_valve

Matt16

Can you explain this one? If the PVC is plugged, then what line does the oil take to get to the air cleaner or TB?

mt_goat

I think blowby gases would be more like exhaust gases. They are from the rings not sealing good and during the high pressure of the combustion the gases leak by and get into the crank case. From there the crank case vent will route them to the intake by way of the PCV tube (along with oil mist). The more gases that get vented by way of the PCV tube the more oil mist that goes along for the ride. Or that's the way I understand it anyway.

Some (including myself) have made a small oil catch can and spliced it into the PCV tubing to catch the oil before it gets into the throttle body and makes a big mess.

904_runner

^pics?????

mt_goat

This is for a 5VZFE, so it may look strange.

904_runner

No, thats fine, i have to swap in a 5vzfe and make it look the same!

mt_goat

There you go, now you're thinking!

Here's some more threads about a catch can:
https://www.yotatech.com/forums/f2/p...mileage-86739/

https://www.yotatech.com/forums/f2/p...an-mod-127953/

Matt16

Those blow-by gases contain fuel and acids which degrade the oil. Luckily, they have a lower boiling point than the oil, and boil at normal engine temperatures. That one reason why you should go on an hour long drive from time to time if you do a lot of city driving.

jason191918

A friend of mine had blow by so bad on his 5.0 bronco that he had to put a breather on the PCV because he would go through air cleaners like no other. Then one day his breather froze shut and all of his oil left through the dipstick hole while on the highway. He was laughing at the cars passing him because they were caked in oil...until he figured out where it was coming from. You can imagine what his engine looked like afterwards...

Moral: catch can is probably better than a breather.

Matt16

or maybe....

jason191918

Most likely. FORD SUCKS. (He is reading this thread right now).

abecedarian

if the PCV valve is plugged, the oil mist may travel through the fresh air hose into the throttle body or air filter housing (depending on where the fresh air into the valve cover is sourced from) then run down through the duct or other path to the filter
for instance, on a 22re, there is the hose from the plenum which the PCV valve is connected to and then there is a second hose (early 22re's had it in front of the throttle plates, later 22re's have it from the plenum) which allows filtered air into the valve cover to replace air drawn out throuth the PCV valve. if the valve plugs, positive pressure could blow oil up the other hose.
I'm not sure of the hose routing on the v6 though, but I've seen other engines that supply fresh air to the crankcase system directly after the air filter.

mt_goat

On my 5VZ there is one hose before the TB and one hose after the TB.

jason191918

On the 3.0, the PCV has a hose that goes to the plenum right above it.



It's the "U" shaped hose here.

On my friends 5.0 bronco, the hose ran to the other side of the air filter, so as air came in, the oil would ruin his air filter.

abecedarian

the PCV valve may be on the U shaped hose, but there should be another hose from a valve cover to the intake somewhere.