I purchased a 2010 / 2.4
So the intake is new also. And was drilled as the recall before install. When I remove the hose out of the valve cover, I get puffs of air out. Same with the oil fill hole, air puffs out, AT IDLE.
From my understanding, there should be, at idle, suction in to the valve cover and air coming out of the oil fill hole at idle.
I also have gotten the FC219 oil cap a while back just to be safe. I have no issues with it. Runs perfect. I don't have any condensation or oil in the air plenum. I'm trying to determine if the pcv orifice is stopped up or not.
My 2 cents,
my simple answer, like ""stopwatch"" said.....
the direction of air flow in the clean side PCV hose,
depends upon how you are driving....
And Specifically for this 2.4 liter GDI equinox
- if you are idling at a stop light, or are coasting with your foot off the gas, and have high intake manifold vacuum of 10 psi or greater,
And then air flows into crankcase from plastic airbox
- if you are accelerating, or even driving with your foot gently on the gas pedal, then you have less then 9 psi of vacuum in your intake manifold,
And then crankcase gunk air, flows out of crankcase and into airbox.
====>>>> .....And my longer explanation .....
... and how to test your dirty side PCV orifice,
.... and ""creeprcris"" I do not think your dirty side PCV is plugged up.....
==>> --- most of the time, crankcase sees positive pressure, which is why I use the cfm oil cap, to keep crankcase at zero psi pressure, the Fc219 has a higher cracking pressure,,,,,,,,, say 1 psi....==>
For my 2013 Equinox with 40k miles and my 2016 Equinox with 19k miles.... both have 2.4 liter, 4 cylinder LEA Ecotec engine
AT IDLE air flows from the plastic "airbox" to the crankcase, via the cleanside breather hose
And then from the crankcase through the dirty side PCV into the intake manifold, and then through intake valves at the top of the combustion chambers (cylinder) and into the combustion chamber.
At IDLE, in my equinox's, the throttle body "butterfly valve" is closed, and the intake manifold sees about a 10 psi vacuum. ( as measured with my scan tool, OBD Link MX + that pairs up nicely with my iPhone.)
The vacuum comes from the pistons in the combustion chamber, when piston goes down, the piston sucks air into the combustion chamber, which creates a vacuum in the intake manifold.
Because the intake manifold is in a vacuum state,
in addition to sucking a little air of air past the closed throttle body butterfly valve ,
the intake manifold also sucks in air from crankcase via dirty side PCV, putting the crankcase is a slight vacuum. Thus the crankcase sucks in air via cleanside PCV breather hose from the airbox. The air in the airbox just flowed through the air filter, the air is clean.
The cleanside PCV hose is pictured at the top of page 3, in the black and white picture. Arrow 1 points to where it plugs into air box,
And the dirty side orifice is at the top of page 4, with the 1/16 inch drill bit partially inside the orifice.
At IDLE, I measured the clean side PCV vacuum.
I do the test, using a manaometer, as described on page 3 of the above link,
At the clean air intake I get vacuum readings readings for both cars of about 0.25 psi of vacuum BUT then I instantly
stopped the test and removed the manometer, allowing air to flow into crankcase. By plugging up the clean side PCV air intake with the manometer, The crankcase achieved a vacuum of of 0.25 psi, which is sufficient to suck air into crankcase via crankshaft rear main seal, and it made a horrible whistling sound.
,.... as soon as I heard the Whistling sound, I discontinued the test. My manometer measured a crankcase vacuum about 0.25 psi,
==>>> according to that ^^^ gm document, my dirty side PCV orifice is not plugged.<<<<====
I also measured CRANKCASE vacuum at OIl CAP at IDLE.
Using a manometer, and using the oil cap shown on post number 15, on the below link, I was able to hook up my manometer to that oil cap. Then I measured crankcase vacuum.
--> My 2016 equinox has a crankcase vacuum at idle of about 0.017 psi vacuum.
And my 2013 Equinox has a bit less crankcase vacuum of about 0.009 psi of vacuum.
The vacuum ^^ is so little, that it is almost zero.
This also makes sense, ^^ since the intake manifold has a vacuum of about 10 psi, and it sucks air into the intake manifold from the crankcase via the dirty side PCV orifice,
and air is flowing into crankcase via cleanside PCV breather hose.
Remember when I plugged up the clean air PCV breather hose, crankcase vacuum went instantly to 0.25 psi of vacuum and then the horrible whistling sound.
AT IDLE with the oil cap off, I feel PUFFS of air coming out of crankcase,
how can it be that PUFFS escape the crankcase out the oil filler hole? ? Since i measured a vacuum on the crankcase of 0.009 and 0.017 psi? The vacuum should suck air into crankcase. And my dirty side PCV is not plugged up according to the GM test?
My guess is, that crankcase pressure fluctuates. Even though I measured it at a uniform 0.009 psi vacuum, I think the crankcase pressure probably very quickly fluctuates between plus 0.1 psi pressure and minus 0.1 psi vacuum,
so fast, that my manometer shows a steady 0.0009 psi vacuum.
As the pistons go up and down, or as piston blow by occurs in each cylinder, the crankcase pressure goes up and then down giving a PUFFing sensation.
==> Theoretically, at idle,
no air should escape out the oil cap at idle. But this 4 cylinder engine does allow air to PUFF out of oil cap. With my cfm oil cap, I am venting these PUFFS, keeping crankcase at zero PSI.
My 6 cylinder 2017 Equinox, at idle does not "PUFF" air out of the oil fill hole when the oil cap is removed. <==
WOT.... WIDE OPEN THROTTLE....
the flow of air through the cleanside PCV breather hose is OPPOSITE to what was described above at IDLE.
During WOT air flows out of crankcase via cleanside PCV into the airbox.
In fact the "air" that flows out of crankcase through the cleanside PCV breathers hose during WOT is laden with crankcase fumes, crankcase moisture, and crankcase gunk.
((Side note==> It is these fumes, moisture and gunk, that can collect in the cleanside PCV breather hose, and when it is say freezing cold outside, 15 degrees F outsde and you are driving at 40 mph, the wind chill is probably -10F, and very quickly the crankcase moisture and gunk in this cleanside breather hose will freeze solid, and stop the crankcase air from escaping via the cleanside PCV breather hose,
then boom, you could have crankshaft rear main seal failure..... ))
I would bet, that if you could put your hand over the opened oil fill hole, while the car is accelerating (WOT) you would feel lots of air blow out the oil fill hole.
Less intake manifold vacuum during WOT results in less suction of crankcase gasses from crankcase via dirty side PCV into the intake manifold.
When I am accelerating hard, I measure intake manifold vacuum at 0 psi,
This makes logical sense since the throttle body "butterfly valve" is wide open, letting as much clean filtered air into the intake manifold as possible. Thus intake manifold vacuum is zero, and it is not sucking air out of crankcase via dirty side PCV.
And when while cruising at 60 mph the throttle body is partially opens and intake manifold vacuum is 3 psi.
In summary, the crankcase sees a POSITIVE crankcase pressure during those WOT ^^ conditions for two reasons.
1. More piston blowby
2. Less intake manifold vacuum
So the air flows out off the crankcase via cleanside PCV hose and into air box.