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JTrexel1;280077 The SB indicates that all repairs associated with this problem would be covered by GM. He then told me that my particular VIN is NOT covered by the SB. One week later said:
FYI, I don't think that anyone on this forum has reported that their situation was covered. Everyone is told that they are NOT on the list ! Crazy.
 

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If this was my vehicle out of warranty I'd get a replacement oil cap, drill a hole in it, put a vent hose on it to the air intake somehow. Relieve that pressure the old fashioned way. This is an absurd situation.
 

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What is most absurd is - - -


JTrexel1
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Having same problem.

Yhashele:

You have documented a very well written assessment of what has happened to your vehicle. I think by submitting this to GM , it will point out a dealership that has done you a disservice . They did not put the case of the problem in your interest to GM.

This is a definite GM documented problem and should have been covered. I am glad you have it fixed and going again, but I feel for the crap you had to go through. Especially the dealer pulling the shuttle service for you. That is really a crime.

Keep on GM and don't give up...
I had same problem with 2013 Equinox. 3 very cold days in a row and rear main blew out. My shop referred me to GM bulletin 14882 and said I should call dealer. Called dealer who acknowledged the bulletin, acknowledged it sounded like my car had that problem, BUT said my VIN was not part of that special coverage bulletin. My NAPA shop replaced the rear main seal, valve cover, air duct assembly and and intake manifold. (I have kept ALL the replaced parts.) Cost me out of pocket $2287. That was this past January. Since then I have talked to the dealer, GM HQ, Better Business Bureau. I Filed for arbitration. It is now July, and all I have gotten was a lot of very polite NO's and tough luck. It seems to me that this problem was acknowledged for that model year, I had that very same problem, GM should step up. VIN should not matter. I read a lot of others have had same problem and same blow off by GM. I wonder how we can start a class action suit?
 

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Another one. 2013 Equinox

Same exact problem a week ago. 2013 Equinox, 10 degs, Rear main seal blowout. I called the local dealer where it happened, by Monticello, WI, and GM. They both said VIN not covered, so too bad.
I towed it 6 hours home (rented a Uhaul car trailer for $65, it pulled really nice, btw) and it looks like I'm going to fix it myself with my son.
It's too bad that it's a known situation by GM, with a TSB out there for a narrow number of VINs, and they won't step up and fix all the vehicles with this issue.
 

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Get ready .. soon as single digit or lower temps start up this winter. . .. .



There'll be more new posters with blown 2.4L main seals.


Get a vented Delco FC219 oil filler cap and keep it cleaned in very cold weather.
 
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Get ready .. soon as single digit or lower temps start up this winter. . .. .



There'll be more new posters with blown 2.4L main seals.


Get a vented Delco FC219 oil filler cap and keep it cleaned in very cold weather.
You need to winter in AZ:wink:
 
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Get ready .. soon as single digit or lower temps start up this winter. . .. .
There'll be more new posters with blown 2.4L main seals.
r.

Jaytee,

Tell me if my logic is correct... I have a question for you.
==>I don't think the 4 cylinder LEA equinox engine ever has crankcase vacuum at idle...<==

Here is my logic.
As you know I have the cfm vented oil cap.... which will, relieve crankcase pressure, but will not let air into crankcase.

My 2016 has 18k miles
The other 2016 has 34 k miles
My 2013 has about 38 k miles
All well maintained.
Low Temperature last night was about 25 degrees, this morning at cold start time 35 degrees, and it warmed up to 45 degrees when I took cars out for a drive, a clear and sunny day. Two equinox's are garage kept, garage is about 10 degrees warmer then outside temperature.

I did a quick "deep dive" , investigation, ... on cfm oil cap and its relation to crankcase pressure or crankcase vacuum / intake manifold vacuum ....here is a simplified explanation....

When I cold started my 4 cylinder equinox's,
The vented oil cap bounces up and down as it lets crankcase pressure escape from crankcase.
My fuel trims are close to zero on both long and short term, which is perfect.

Scan tool, tells me intake manifold VACUUM is about 8 psi....at idle, at Start up, which is normal.
( 8psi vacuum = minus 8 psi)
Thus theoretically, ~~>since the intake manifold is pulling a strong 8psi vacuum, it should be sucking much crankcase fumes through the dirty side PCV , and thus putting crankcase in a vacuum <~~p

After 5 minutes of idling, still no change, I still have the ball in the vented cfm oil cap bouncing up and down relieving crankcase pressure.
I pull off the decorative plastic filter cover off cfm oil cap and I feel air blowing out. Like lots of little puffs of air.

Here is my guesss...
I am not sure, ....but perhaps the "noise" comes from the nylon ball hitting the top of the cfm oil cap , "aluminum housing stop" as the crankcase gas pushes the ball up,
and then after hitting the aluminum housing top, it bounces down along with gravity. Then, as the nylon "ckeck valve" ball gets close to "sealing" the crankcase, the air escaping from crankcase pushes the ball upward and out of the way again.... hence the pulsing of air out of engine.

If I put my hand flat on cfm oil cap, I can stop the air from exiting crankcase via oil cap,
Thus no air comes out and nylon check valve ball ball stops bouncing, it is silent. Take my hand off, and nylon ball bounces up and down again...
^^^^ that is cold start ^^^ and 5 minute warm up on all three 4 cylinder equinox's.
NEXT,
Then I take the equinox out for a 50 minute drive around town, stoplights, top speed 45 mph, and sun is out it is 50 degrees outside. Come home let car idle for a few Minutes and pop open hood, remove the decorative cfm oil filter cap,
And air is still blowing out of crankcase through cfm oil cap
And
Intake manifold has a vacuum of 8 psi per scan tool.(perfect)

Repeat ^^ with other 2016 Equinox, same results.

My Conclusion... is that the crankcase never sees a vacuum
Even though intake manifold is pulling 8psi vacuum at idle.

PART 2, V6 equinox with cfm oil cap. ( 6 cylinder has 24 k Miles on it)
My 2017 V6 equinox, started it up this morning , after it was parked outside all night, low temp of 25 degrees F, it was 35 F when I cold started it
Pop open hood, remove decorative oil cap filter....
And no rattle of cfm vented oil cap, it stayed shut,
since the intake manifold is pulling a vacuum at idle,
thus also putting the crankcase in a vacuum, so the cfm "check valve sealed" the oil cap, not allowing any air into crankcase. (And no air is blowing out when I put my hand on it)
Intake manifold vacuum at idle is 10psi using scan tool
( 10 psi vacuum = negative 10 psi)
And then,
After driving a V6, to warm it up, and letting it idle, pop hood, remove decorative cfm oil cap filter, Checking the cfm oil cap, and again, no rattle, no air escaping out of cfm oil cap, because crankcase is under vacuum because intake manifold is under vacuum under idle since throttle body is closed
thus crankcase is under vacuum ( no air Escaping out of cfm oil cap) ... JUST LIKE it should be according to PCV theory

So here is what I think,
PLEASE COMMENT ===>
1
I don't think the equinox LEA 4 cylinders intake manifold pulls enough vacuum through the "Dirty side internal pcv orifice" at idle, to put the Crankcase in a vacuum...
... even on newer low mile, well maintained 2016's,
and today, even after engine is warmed up, it certainly is not putting the crankcase in a vacuum.
if crankcase was in vacuum it would not expel crankcase gas via vented cfm oil cap
The crankcase is not seeing a vacuum at idle.


And 2
Thus the dirty side PCV orifice must be plugged or has restricted air flow, even after a 50 minute drive on a day where temperature is 45 degrees and sunny, the dirty side PCV orifice is still restricted or plugged.... even on newer equinox.

And 3
the 6 cylinder's "dirty side EXTERNAL PCV orifice " does exactly what it is designed to do.... it puts the crankcase in a vacuum at idle.... since The vented oil cap "is not venting" , it is sealed shut, thus crankcase is in vacuum. <<<===
 

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Thanks for the very good write up and detective work. I Pretty much agree with your conclusions.

And, in the case of the GM 2.4L engine, even the "clean side" isn't relieving the pulsations by allowing enough (any?) air to flow into the intake via the throttle body which is kind of surprising.
Without knowing exactly what the entire clean side air flow path might be from the crankcase to the valve cover where the clean side allows/vents PCV vapors, and without knowing exactly what the PCV flow path is for the internal PCV orifice . . . this all seems interesting and points out that the system does not function as well as it should. As we all know.

I'm thinking even when the PCV orifice is not clogged, it's size and possibly other path restrictions, do not function well enough to allow all air flow completely.



On a related note . . I also have tried a vented cap (and also the FC219) on our 2017 1.8L four banger Sonic engine. It also, exhibits some air pulsations when a vented oil filler cap is used, but not as pronounced as you described. I have as yet, connected my OBD II scanner to the Sonic to see what pressures are at idle for intake.

I can say, I don't notice any clicking of bouncing of the check valve in the other vented filler cap I purchased. It originally did not have a ball, but I found a 1/4" ball that fit and does the trick. But it essentially stays in place during idle. . . . or moves so little that I notice no sound.


Before selling our 2015 Equinox 3.6L V6, I also checked and found that if i installed a vented filler cap, it remained closed as you also found.

So that 3.6L V6 apparently has a properly designed PCV path and also provides enough vacuum even at idle unlke the 2.4L engine.



The bottom line seems to be that the 2.4L PCV path fails to provide sufficient flow of PCV vapors and a vented oil filler cap would be a wise addition to provide pressure release at idle as well as while driving should the internal PCV orifice freeze or clog with carbon and combustion debris.











Jaytee,

Tell me if my logic is correct... I have a question for you.
==>I don't think the 4 cylinder LEA equinox engine ever has crankcase vacuum at idle...<==

Here is my logic.
As you know I have the cfm vented oil cap.... which will, relieve crankcase pressure, but will not let air into crankcase.

My 2016 has 18k miles
The other 2016 has 34 k miles
My 2013 has about 38 k miles
All well maintained.
Low Temperature last night was about 25 degrees, this morning at cold start time 35 degrees, and it warmed up to 45 degrees when I took cars out for a drive, a clear and sunny day. Two equinox's are garage kept, garage is about 10 degrees warmer then outside temperature.

I did a quick "deep dive" , investigation, ... on cfm oil cap and its relation to crankcase pressure or crankcase vacuum / intake manifold vacuum ....here is a simplified explanation....

When I cold started my 4 cylinder equinox's,
The vented oil cap bounces up and down as it lets crankcase pressure escape from crankcase.
My fuel trims are close to zero on both long and short term, which is perfect.

Scan tool, tells me intake manifold VACUUM is about 8 psi....at idle, at Start up, which is normal.
( 8psi vacuum = minus 8 psi)
Thus theoretically, ~~>since the intake manifold is pulling a strong 8psi vacuum, it should be sucking much crankcase fumes through the dirty side PCV , and thus putting crankcase in a vacuum <~~p

After 5 minutes of idling, still no change, I still have the ball in the vented cfm oil cap bouncing up and down relieving crankcase pressure.
I pull off the decorative plastic filter cover off cfm oil cap and I feel air blowing out. Like lots of little puffs of air.

Here is my guesss...
I am not sure, ....but perhaps the "noise" comes from the nylon ball hitting the top of the cfm oil cap , "aluminum housing stop" as the crankcase gas pushes the ball up,
and then after hitting the aluminum housing top, it bounces down along with gravity. Then, as the nylon "ckeck valve" ball gets close to "sealing" the crankcase, the air escaping from crankcase pushes the ball upward and out of the way again.... hence the pulsing of air out of engine.

If I put my hand flat on cfm oil cap, I can stop the air from exiting crankcase via oil cap,
Thus no air comes out and nylon check valve ball ball stops bouncing, it is silent. Take my hand off, and nylon ball bounces up and down again...
^^^^ that is cold start ^^^ and 5 minute warm up on all three 4 cylinder equinox's.
NEXT,
Then I take the equinox out for a 50 minute drive around town, stoplights, top speed 45 mph, and sun is out it is 50 degrees outside. Come home let car idle for a few Minutes and pop open hood, remove the decorative cfm oil filter cap,
And air is still blowing out of crankcase through cfm oil cap
And
Intake manifold has a vacuum of 8 psi per scan tool.(perfect)

Repeat ^^ with other 2016 Equinox, same results.

My Conclusion... is that the crankcase never sees a vacuum
Even though intake manifold is pulling 8psi vacuum at idle.

PART 2, V6 equinox with cfm oil cap. ( 6 cylinder has 24 k Miles on it)
My 2017 V6 equinox, started it up this morning , after it was parked outside all night, low temp of 25 degrees F, it was 35 F when I cold started it
Pop open hood, remove decorative oil cap filter....
And no rattle of cfm vented oil cap, it stayed shut,
since the intake manifold is pulling a vacuum at idle,
thus also putting the crankcase in a vacuum, so the cfm "check valve sealed" the oil cap, not allowing any air into crankcase. (And no air is blowing out when I put my hand on it)
Intake manifold vacuum at idle is 10psi using scan tool
( 10 psi vacuum = negative 10 psi)
And then,
After driving a V6, to warm it up, and letting it idle, pop hood, remove decorative cfm oil cap filter, Checking the cfm oil cap, and again, no rattle, no air escaping out of cfm oil cap, because crankcase is under vacuum because intake manifold is under vacuum under idle since throttle body is closed
thus crankcase is under vacuum ( no air Escaping out of cfm oil cap) ... JUST LIKE it should be according to PCV theory

So here is what I think,
PLEASE COMMENT ===>
1
I don't think the equinox LEA 4 cylinders intake manifold pulls enough vacuum through the "Dirty side internal pcv orifice" at idle, to put the Crankcase in a vacuum...
... even on newer low mile, well maintained 2016's,
and today, even after engine is warmed up, it certainly is not putting the crankcase in a vacuum.
if crankcase was in vacuum it would not expel crankcase gas via vented cfm oil cap
The crankcase is not seeing a vacuum at idle.


And 2
Thus the dirty side PCV orifice must be plugged or has restricted air flow, even after a 50 minute drive on a day where temperature is 45 degrees and sunny, the dirty side PCV orifice is still restricted or plugged.... even on newer equinox.

And 3
the 6 cylinder's "dirty side EXTERNAL PCV orifice " does exactly what it is designed to do.... it puts the crankcase in a vacuum at idle.... since The vented oil cap "is not venting" , it is sealed shut, thus crankcase is in vacuum. <<<===
 

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JayTee - I nominate you as our forum's Honorary Rear Main Seal Blow-out Authority - pun intended ! Happy Holidays !
 

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My comments are in red below.

Jaytee,

Tell me if my logic is correct... I have a question for you.
==>I don't think the 4 cylinder LEA equinox engine ever has crankcase vacuum at idle...<==

Did you test crankcase vacuum according to the TSB link and instructions you posted on this forum. Curious to know. If you don't have manometer, just plug the hard PCV line and listen for vacuum whistle on the rear of the engine. This is air being pulled passed your main seal.
Another method is to block the tube, and pull your dipstick. You should feel a slight vacuum at the the dispstick tube. It is a very slight vacuum or neutral pressure if the PCV orifice is functioning.


Here is my logic.
As you know I have the cfm vented oil cap.... which will, relieve crankcase pressure, but will not let air into crankcase.

I submit it does let small amounts of air into the crankcase, as it is pushed upward and pulled downward but not enough or long enough duration for the O2 sensor to detect it and for the ECU to make adjustments.in fuel trim.

My 2016 has 18k miles
The other 2016 has 34 k miles
My 2013 has about 38 k miles
All well maintained.
Low Temperature last night was about 25 degrees, this morning at cold start time 35 degrees, and it warmed up to 45 degrees when I took cars out for a drive, a clear and sunny day. Two equinox's are garage kept, garage is about 10 degrees warmer then outside temperature.

I did a quick "deep dive" , investigation, ... on cfm oil cap and its relation to crankcase pressure or crankcase vacuum / intake manifold vacuum ....here is a simplified explanation....

When I cold started my 4 cylinder equinox's,
The vented oil cap bounces up and down as it lets crankcase pressure escape from crankcase.
My fuel trims are close to zero on both long and short term, which is perfect.

At start up you should be in open loop, and it will show close to zero for both. This is not perfect. It just means that it is using a default fuel map, rather than full fuel control via the O2 sensors and ECU. Can you post a snapshot of your screen showing other parameters. Pulses of pressure and vacuum are present at idle. It is much easier to detect pressure than vacuum as you noted with your lightweight nylon ball in the cap. I have documented short periods of low pressure events at cold startup. Blow-by is higher when cold due to thermal dynamics, and decreases as the engine warms and the rings and pistons expand. This is supported in my extensive investigation of crankcase, manifold and intake pressures and vacuum using a professional manometer.


Scan tool, tells me intake manifold VACUUM is about 8 psi....at idle, at Start up, which is normal.
( 8psi vacuum = minus 8 psi)
Thus theoretically, ~~>since the intake manifold is pulling a strong 8psi vacuum, it should be sucking much crankcase fumes through the dirty side PCV , and thus putting crankcase in a vacuum <~~p

What model of scan tool are you using? There is no vacuum sensor in the engine, only an Manifold Absolute Pressure sensor. Your equation is not correct. There is no direct equivalent between PSI vacuum and negative psi. That does not make sense at all, "PSI vacuum"
What PID are you reading on your scan tool?

After 5 minutes of idling, still no change, I still have the ball in the vented cfm oil cap bouncing up and down relieving crankcase pressure.
I pull off the decorative plastic filter cover off cfm oil cap and I feel air blowing out. Like lots of little puffs of air.

Puffs of air is normal, even in my mostly rebuilt 2.4L with factory compression and free flowing PCV system.

Here is my guesss...
I am not sure, ....but perhaps the "noise" comes from the nylon ball hitting the top of the cfm oil cap , "aluminum housing stop" as the crankcase gas pushes the ball up,
and then after hitting the aluminum housing top, it bounces down along with gravity. Then, as the nylon "ckeck valve" ball gets close to "sealing" the crankcase, the air escaping from crankcase pushes the ball upward and out of the way again.... hence the pulsing of air out of engine.

So based on these observations you conclude that no vacuum is present and the downward movement is due to physics and gravity. Yet, you take no direct vacuum measurements in the intake manifold or the crankcase. Not what I call a deep dive investigation.

If I put my hand flat on cfm oil cap, I can stop the air from exiting crankcase via oil cap,
Thus no air comes out and nylon check valve ball ball stops bouncing, it is silent. Take my hand off, and nylon ball bounces up and down again...
^^^^ that is cold start ^^^ and 5 minute warm up on all three 4 cylinder equinox's.

Of course the lightweight nylon ball stops moving, you are blocking air flow. Air will seek the path of least resistance, just like water, and will either be drawn out through the orifice or through the camshaft cover to the intake.

NEXT,
Then I take the equinox out for a 50 minute drive around town, stoplights, top speed 45 mph, and sun is out it is 50 degrees outside. Come home let car idle for a few Minutes and pop open hood, remove the decorative cfm oil filter cap,
And air is still blowing out of crankcase through cfm oil cap
And
Intake manifold has a vacuum of 8 psi per scan tool.(perfect)

I would disagree that it is perfect, far from it. MAP readings at full operating temps for the 2.4L engine should be around 4psi at idle and will reach as much as 14psi at full open throttle.

You really need to get a mechanical vacuum gauge and measure intake manifold vacuum.

To convert MAP PSI reading, you need to subtract that reading from the reading you get when it is reading atmosphere pressure(engine off), and then multiply by 2. My Nox, reads 4psi when warm, 14.5 psi when the engine is off. Difference is 10.5 and mulitply by 2, and you will get your vacuum in Inches of Mercury (InHg). 20-22 inHg is normal at temp for this engine at idle and deceleration.


Repeat ^^ with other 2016 Equinox, same results.

My Conclusion... is that the crankcase never sees a vacuum
Even though intake manifold is pulling 8psi vacuum at idle.

Your conclusion is flawed from the onset because you base it on mere observations of a vented cap which was not design for this engine, you take no vacuum measurements at all in the crankcase, and your incorrect correlation in MAP reading to intake vacuum. You seem to forget that you have rotating mass, creating significant movement of air in the crankcase and you of course have some blow-by which is normal in all engines. If you measured pressure and vacuum over a period of time, and the majority of time is indicating, it does mean you NEVER have vacuum. I am willing to bet your have net total vacuum in your engine, even with the normal pulses of air.



PART 2, V6 equinox with cfm oil cap. ( 6 cylinder has 24 k Miles on it)
My 2017 V6 equinox, started it up this morning , after it was parked outside all night, low temp of 25 degrees F, it was 35 F when I cold started it
Pop open hood, remove decorative oil cap filter....
And no rattle of cfm vented oil cap, it stayed shut,
since the intake manifold is pulling a vacuum at idle,
thus also putting the crankcase in a vacuum, so the cfm "check valve sealed" the oil cap, not allowing any air into crankcase. (And no air is blowing out when I put my hand on it)
Intake manifold vacuum at idle is 10psi using scan tool
( 10 psi vacuum = negative 10 psi)
And then,
After driving a V6, to warm it up, and letting it idle, pop hood, remove decorative cfm oil cap filter, Checking the cfm oil cap, and again, no rattle, no air escaping out of cfm oil cap, because crankcase is under vacuum because intake manifold is under vacuum under idle since throttle body is closed
thus crankcase is under vacuum ( no air Escaping out of cfm oil cap) ... JUST LIKE it should be according to PCV theory

You are comparing apples to oranges with these two engines. The V6 external fitting has multiple orifices, has large direct feed to the intake manifold. The difference in observed pulses is explained by the fact you have 50% more pulses of air during the same crank rotation, of smaller pressure, shorter stroke of the piston, V-6 design with two banks of cylinders, and probably lower blow-by in general. V-8 engines have even less noticeable pulses of air. Have you ever felt the crankcase pulses from the oil fill cap on a Harley Davidson motorcycle with a long piston stroke. Quite substantial.

You really should do more investigation and theory on Positive Crankcase Ventilation systems, both the older type and the newer orifice types. Also study pressure differential and air flow across an orifice.

So here is what I think,
PLEASE COMMENT ===>
1
I don't think the equinox LEA 4 cylinders intake manifold pulls enough vacuum through the "Dirty side internal pcv orifice" at idle, to put the Crankcase in a vacuum...
... even on newer low mile, well maintained 2016's,
and today, even after engine is warmed up, it certainly is not putting the crankcase in a vacuum.
if crankcase was in vacuum it would not expel crankcase gas via vented cfm oil cap
The crankcase is not seeing a vacuum at idle.

The PCV system was not design to eliminate the pulse of air at the oil fill cap.
It was design to draw any excess combustion blow-by from the crankcase, creating an overall net vacuum condition in the crankcase. Blow-by is least at idle, and thus the purpose of the restricted orifice design.

And 2
Thus the dirty side PCV orifice must be plugged or has restricted air flow, even after a 50 minute drive on a day where temperature is 45 degrees and sunny, the dirty side PCV orifice is still restricted or plugged.... even on newer equinox.

Seriously doubt the orifice is plugged or restricted. Why would you drive three cars and spend all that time just to come up with this theory that the orifice is plugged when you could have tested the PCV system within a few minutes.

And 3
the 6 cylinder's "dirty side EXTERNAL PCV orifice " does exactly what it is designed to do.... it puts the crankcase in a vacuum at idle.... since The vented oil cap "is not venting" , it is sealed shut, thus crankcase is in vacuum. <<<===
Again you base it on mere observation of a vented oil cap that was not designed for this vehicle, and not intended for the purpose which you are using it. This is not my words, this is from the manufacturer of the cap.

Suggest you go out and spend a whole $35 dollars and get yourself a digital manometer and see if you can duplicate all of my testing considering that that you have three NOXs. Also, while your at it buy a FC219 cap and do the testing that you asked CopperHead to do for you.
 

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My comments and questions are below in red.

Thanks for the very good write up and detective work. I Pretty much agree with your conclusions.

LOL, Detective Work.....so where is your critical analysis of the referenced post. Wait, both of you are pushing this untested, unapproved vented oil fill cap from CFM Performance, and now are just grasping at straws. So you agree with the flawed and mis-guided conclusions of ThreeNox that there is insufficient vacuum to keep the bouncing nylon ball from moving.

You two remind of the video of the cat chasing the laser light on the floor as onlookers watch in amusement.



And, in the case of the GM 2.4L engine, even the "clean side" isn't relieving the pulsations by allowing enough (any?) air to flow into the intake via the throttle body which is kind of surprising.

It was not designed to prevent the pulses of air or movement of the bouncing nylon ball. Not surprising at all, if one takes the time to understand how the PCV system is designed. There is virtually zero vacuum in the intake plenum before the throttle body at idle because it is mostly closed. The orifice is drawing the excess blow-by and moisture. The path from crankcase to the vented oil cap with the bouncing nylon ball is unobstructed, so naturally you see the results of movement of air in relatively closed system. Air will seek the shortest path and of least resistance.


Without knowing exactly what the entire clean side air flow path might be from the crankcase to the valve cover where the clean side allows/vents PCV vapors, and without knowing exactly what the PCV flow path is for the internal PCV orifice . . . this all seems interesting and points out that the system does not function as well as it should. As we all know.

I have posted pictures of the internal baffling of the camshaft cover, the orifice, the inside and outside of the air/oil separator, as well as the orifice and head, and provided a description of the path of air flow in the system as well as what the normal pressure and vacuum measurements in the crankcase, intake and air plenum. Pulling moisture, oil mist, fuel vapor, and combustion by-products out the crankcase, and depositing them in the oil/air separator, not allowing them to re-enter the intake I would say is working as designed. The problem is that GM doesn't bother telling customers they need to check and drain the separator on a regular basis or to test the orifice for blockage until it is too late.

I'm thinking even when the PCV orifice is not clogged, it's size and possibly other path restrictions, do not function well enough to allow all air flow completely.

And this is based on the bouncing nylon ball of an untested vented oil fill cap. My actual testing shows on average a net vacuum in the crankcase at nearly all operating conditions.


On a related note . . I also have tried a vented cap (and also the FC219) on our 2017 1.8L four banger Sonic engine. It also, exhibits some air pulsations when a vented oil filler cap is used, but not as pronounced as you described. I have as yet, connected my OBD II scanner to the Sonic to see what pressures are at idle for intake.

I can say, I don't notice any clicking of bouncing of the check valve in the other vented filler cap I purchased. It originally did not have a ball, but I found a 1/4" ball that fit and does the trick. But it essentially stays in place during idle. . . . or moves so little that I notice no sound.


Before selling our 2015 Equinox 3.6L V6, I also checked and found that if i installed a vented filler cap, it remained closed as you also found.

So that 3.6L V6 apparently has a properly designed PCV path and also provides enough vacuum even at idle unlke the 2.4L engine.

Did you measure crankcase vacuum under various driving conditions on the 3.6L V6?You are also comparing apples to oranges between the I4 and the V6 in terms of the turbulence of air in the crankcase.

The bottom line seems to be that the 2.4L PCV path fails to provide sufficient flow of PCV vapors and a vented oil filler cap would be a wise addition to provide pressure release at idle as well as while driving should the internal PCV orifice freeze or clog with carbon and combustion debris.

I submit it does remove PCV vapors, but just does not want to play with your silly bouncing nylon ball. A vented cap like CFM Performance would cause the combustion by-products, moisture, and emulsified oil to remain in the engine, causing breakdown of the oil and damage to the engine.

I have been searching for over a year and have not found any evidence other than carbon clogging the orifice. After a full year, my cylinder head opening feeding the orifice only contained a few drops of golden colored oil. What is combustion debris? Pictures please.
 

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Not being drawn anymore into a discussion of PCV freezing. clogging, short comings that have been posted 2 and 3 years ago before.

Thank you for your viewpoints and investigation.



Readers should know that - - -

In the end it really isn't any different (and more dogmatic about what to do) than what others posted in threads 2 and 3 years ago about what the 2.4L PCV shortcomings in cold weather reveals in particular.


In one week it's a new year everyone ! With more new adventures . :grin:
 
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Jaytee,

Tell me if my logic is correct... I have a question for you.
==>I don't think the 4 cylinder LEA equinox engine ever has crankcase vacuum at idle...<==

Here is my logic.
As you know I have the cfm vented oil cap.... which will, relieve crankcase pressure, but will not let air into crankcase.

My 2016 has 18k miles
The other 2016 has 34 k miles
My 2013 has about 38 k miles
All well maintained.
Low Temperature last night was about 25 degrees, this morning at cold start time 35 degrees, and it warmed up to 45 degrees when I took cars out for a drive, a clear and sunny day. Two equinox's are garage kept, garage is about 10 degrees warmer then outside temperature.

I did a quick "deep dive" , investigation, ... on cfm oil cap and its relation to crankcase pressure or crankcase vacuum / intake manifold vacuum ....here is a simplified explanation....

When I cold started my 4 cylinder equinox's,
The vented oil cap bounces up and down as it lets crankcase pressure escape from crankcase.
My fuel trims are close to zero on both long and short term, which is perfect.

Scan tool, tells me intake manifold VACUUM is about 8 psi....at idle, at Start up, which is normal.
( 8psi vacuum = minus 8 psi)
Thus theoretically, ~~>since the intake manifold is pulling a strong 8psi vacuum, it should be sucking much crankcase fumes through the dirty side PCV , and thus putting crankcase in a vacuum <~~p

After 5 minutes of idling, still no change, I still have the ball in the vented cfm oil cap bouncing up and down relieving crankcase pressure.
I pull off the decorative plastic filter cover off cfm oil cap and I feel air blowing out. Like lots of little puffs of air.

Here is my guesss...
I am not sure, ....but perhaps the "noise" comes from the nylon ball hitting the top of the cfm oil cap , "aluminum housing stop" as the crankcase gas pushes the ball up,
and then after hitting the aluminum housing top, it bounces down along with gravity. Then, as the nylon "ckeck valve" ball gets close to "sealing" the crankcase, the air escaping from crankcase pushes the ball upward and out of the way again.... hence the pulsing of air out of engine.

If I put my hand flat on cfm oil cap, I can stop the air from exiting crankcase via oil cap,
Thus no air comes out and nylon check valve ball ball stops bouncing, it is silent. Take my hand off, and nylon ball bounces up and down again...
^^^^ that is cold start ^^^ and 5 minute warm up on all three 4 cylinder equinox's.
NEXT,
Then I take the equinox out for a 50 minute drive around town, stoplights, top speed 45 mph, and sun is out it is 50 degrees outside. Come home let car idle for a few Minutes and pop open hood, remove the decorative cfm oil filter cap,
And air is still blowing out of crankcase through cfm oil cap
And
Intake manifold has a vacuum of 8 psi per scan tool.(perfect)

Repeat ^^ with other 2016 Equinox, same results.

My Conclusion... is that the crankcase never sees a vacuum
Even though intake manifold is pulling 8psi vacuum at idle.

PART 2, V6 equinox with cfm oil cap. ( 6 cylinder has 24 k Miles on it)
My 2017 V6 equinox, started it up this morning , after it was parked outside all night, low temp of 25 degrees F, it was 35 F when I cold started it
Pop open hood, remove decorative oil cap filter....
And no rattle of cfm vented oil cap, it stayed shut,
since the intake manifold is pulling a vacuum at idle,
thus also putting the crankcase in a vacuum, so the cfm "check valve sealed" the oil cap, not allowing any air into crankcase. (And no air is blowing out when I put my hand on it)
Intake manifold vacuum at idle is 10psi using scan tool
( 10 psi vacuum = negative 10 psi)
And then,
After driving a V6, to warm it up, and letting it idle, pop hood, remove decorative cfm oil cap filter, Checking the cfm oil cap, and again, no rattle, no air escaping out of cfm oil cap, because crankcase is under vacuum because intake manifold is under vacuum under idle since throttle body is closed
thus crankcase is under vacuum ( no air Escaping out of cfm oil cap) ... JUST LIKE it should be according to PCV theory

So here is what I think,
PLEASE COMMENT ===>
1
I don't think the equinox LEA 4 cylinders intake manifold pulls enough vacuum through the "Dirty side internal pcv orifice" at idle, to put the Crankcase in a vacuum...
... even on newer low mile, well maintained 2016's,
and today, even after engine is warmed up, it certainly is not putting the crankcase in a vacuum.
if crankcase was in vacuum it would not expel crankcase gas via vented cfm oil cap
The crankcase is not seeing a vacuum at idle.


And 2
Thus the dirty side PCV orifice must be plugged or has restricted air flow, even after a 50 minute drive on a day where temperature is 45 degrees and sunny, the dirty side PCV orifice is still restricted or plugged.... even on newer equinox.

And 3
the 6 cylinder's "dirty side EXTERNAL PCV orifice " does exactly what it is designed to do.... it puts the crankcase in a vacuum at idle.... since The vented oil cap "is not venting" , it is sealed shut, thus crankcase is in vacuum. <<<===
What brand of scan tool did you use and what PID were you using for the PSI reading above.

MAP PSI of the intake should be around 4psi at idle at full operating temps. If you are ready 8psi on the MAP, you have mechanical problem or vacuum leak.
 

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Hey sydnesb, I KNOW you will LOVE this. The CFM ball freezes shut, so i use this instead: Been running this all winter without issue. I ll let the pics do the talking. :::
A draft tube I presume. Did you take fuel trim measurements before and after? Your trims will likely jump 10-15pts.

What is your definition of "without issue"? Engine didn't blow up or the rear seal didn't blow.

As Jaytee2014 would say, one example is insignificant.
 

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Hey sydnesb, I KNOW you will LOVE this. The CFM ball freezes shut, so i use this instead: Been running this all winter without issue. I ll let the pics do the talking. :::
A draft tube I presume. Did you take fuel trim measurements before and after? Your trims will likely jump 10-15pts.

What is your definition of "without issue"? Engine didn't blow up or the rear seal didn't blow.

As Jaytee2014 would say, one example is insignificant.
the long tube is so that you cannot smell the oil fumes in the cabin. no change in trims. I presume it is because these engines have so much blow by and the pcv is clearly overwhelmed leaving the draft tube as the relief the system needs.
.
 

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also just monitored fuel trims and they are fluctuating closer to 0 now as compared to were they were with the cfm or the stock cap. my guess is that the engineers did not account for excessive blow by from the piston rings when they designed the pcv system which basically allows for minimum crankcase air circulation. also the system I m using is venting dirty blow by into the air instead of into the intake onto the intake valves which may decrease carbon buildup and therefore decrease the risk of oil burning on the clean side.
 

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also just monitored fuel trims and they are fluctuating closer to 0 now as compared to were they were with the cfm or the stock cap. my guess is that the engineers did not account for excessive blow by from the piston rings when they designed the pcv system which basically allows for minimum crankcase air circulation. also the system I m using is venting dirty blow by into the air instead of into the intake onto the intake valves which may decrease carbon buildup and therefore decrease the risk of oil burning on the clean side.
The engineers did not account for owners not fixing the root cause of the excessive blow-by. A normally operating 2.4L engine does not have this problem.

How do you know all the contaminates, emulsified oil, moisture, fuel acids, etc are being vented and not remaining in the engine? The reservoir in the intake plenum was designed to catch these contaminants, but due to venting from another location, they likely remain in the engine.

You have OBDII app on your phone, correct, do a video showing the fuel trims with the stock cap at idle, and then remove and replace with the draft tube, without stopping or editing the video.

I and others are more inclined to believe no affect on fuel trims with video evidence.
 
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