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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

GM does not install any catch can on the low side of the PCV system. GM only installed a "catch can" on the high side of the PCV. The aftermarket catch can I installed is on the low side of the PCV system.

A brief overview of the PCV system: "PCV" is short for "Positive Crankshaft Ventilation". The purpose: some fuel/air and exhaust gas blows by the piston rings in the cylinders. These blow-by will collect in the oil pan, eventually raising pressure so high it would blow lower oil seals. Back in the 70's, car manufacturers simply added crankcase vents to the valve covers. These vents allow the blow-by to vent out of the engine so the crankcase pressure would stay neutral (not pressurized). Years later, EPA comes in making these vents illegal because these blow-by gases are pollution. So in comes the PCV system.

Since manufacturers cannot vent the blow-by gases from the crankcase, they now suck the blow-by gases into the intake manifold to be mixed with the incoming air and re-ignited then exhausted. So generally there is now a PCV hose from the valve cover to the intake manifold. This is the low side of the PCV system. Since the intake manifold is almost always under vacuum, it is constantly sucking the blow-by gases from the crankcase. This system is further enhanced by bringing in a small stream of fresh air into the crankcase. So there is another PCV hose from the intake air duct to the other valve cover (or could be connected else where - anywhere that eventually goes through the crankcase). This is the high side. This high side hose has to be connected to the air source upstream of the throttle body because this air stream needs to be at near ambient pressure (which is higher pressure than the intake manifold).

So in driving conditions, say <80% throttle:
1) a small part of fresh air is diverted front in front of the throttle body to perhaps the front valve cover
2) the fresh air breezes through the crankcase, mixing with gaseous blow-bys and picks up moisture vapors and oil vapors
3) the nasty mix is sucked up perhaps through the opposing, rear valve cover
4) the nasty mix is sucked through the low side hose directly into the intake manifold
5) the nasty mix is mixed with the large portion of incoming air that was passed through the throttle body and will eventually be burned off in combustion

When the engine is at normal operating condition, this isn't a problem because the oil vapors in the intake manifold do not cool enough to condense and solidify as carbon deposits. However, when the engine is turned off (vehicle parked), the intake system cools down, and whatever vapors were brought up through the PCV system begins to cool.

As most of you know, GM had trouble with carbon deposits forming by the throttle blades when they changed to "Drive by Wire". One scenario was at WOT (wide open throttle), the intake manifold pressure is very similar to the intake hose pressure in front of the throttle blades (duh because the throttle is wide open causing nearly no significant pressure drop). During these WOT operations, the PCV is not circulating air through the crankcase (because there is no longer any vacuum at the intake manifold). Compounding the problem, during WOT there are more piston gaseous blow-by (due to higher engine rpm). What happens then is the crankcase pressure builds higher than the intake air in front of the throttle body. This means before when the fresh air was flowing through the small hose from the front intake to the front valve cover (the high side), the flow is now reversed. The gaseous blow-by and oil vapors are reversed up this high side PCV hose, and the oil vapors deposit onto the throttle body. Definitely not good as these eventual carbon deposits affect the throttle body. How does GM address this? They added their little "catch can" on the high side of the PCV by the intake duct. This is the "catch can" rbarrios is checking. There's only about 1/2 a tablespoon of oil over 5k miles in that catch can of the high side. Indeed, but it's better to catch that oil in there than to let it deposit on the throttle body. (In earlier years like the 90's, the carbon deposits on the throttle body was not as concerning because we simply pressed a little bit harder down on our accelerator pedals to break up any interference. Apparently something these little stepper motors can't handle today.)

Now now - let's go back to the low side PCV. When not driving at WOT, all that nasty blow-by, vapors, etc are being directly sucked into the intake manifold. Absolutely nothing filtering this out. In the 90's this didn't matter because the fuel injectors kept washing away any deposits on the intake valves. Who cares about carbon deposits on the intake manifold because it doesn't have any significant effect on engine performance. When GM changed to using direct injection - they claim they optimized fuel spray timing to spray on the intake valve when the valve is opened into the cylinder. Some of their simulations show this as well. But there are also other pictures showing severe carbon deposits on the intake valves. Who's right? I don't know.

Because I don't know, I prefer to be safe and installed the aftermarket PCV oil catch can. This aftermarket oil catch can is installed on the low side of the PCV system (where there is not any installed by GM). This low side PCV oil catch can fills up much faster than the OEM high side oil catch can. I don't have measurements, but my estimate would be about 1 cup of oil/moisture vapors filtered out every 3k miles.

Maybe GM really does have the direct fuel injection timing optimized to wash the intake valves while it's open during run time. And the aftermarket catch can is capturing gunk that would be washed away anyway. Or maybe the timing is not sufficient, and carbon deposits build on the intake valves. It is strictly my opinion: the intake valve is not physcially opened far enough for long enough for the fuel injectors to sufficiently keep washing it clean. Again, IMO: the oil catch can significantly reduces the amount of deposits the fuel injectors would need to wash off the valves.

I'm quite meticulous like rbarrios is with his 'Nox. Perhaps we'll make a good comparison at 100k miles. If by then we're both willing to open up our intakes, we can take a look at the valves to see if my oil catch can made any difference. Maybe it did, maybe not. If not, I just blew $150. (IMO, not a big deal considering what I might be protecting.) :shrug:
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

And there is a PCV valve in the low side system that regulates the PCV flow. For simplicity's sake, I left out that valve.
But apparently, this PCV valve orifice is a little too small for the direct injection engine. There are mods for drilling out the holes a little more to help with the crankcase excavation. I think I saw somewhere it was a design change implemented for 2015. So I might do this mod myself for my 2013.

*Do not mix the low side and high side of the PCV system. There are some who think to add a "T" to tie both hoses together. If you understood how the system works, you'll realize connecting the high and low side hoses will defeat the purpose of the PCV system!
 

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Discussion Starter #63
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

rbarrios said:
ohh the Mod-- will give you a reason to delete the dealer sticker added on the tailgate...

and--- in 30,000 miles--- have not gotten a milkshake in the Nox. (then again no looong drives thru rain)
Thanks for the pictures of the milky oil. Up further north it doesn't even have to rain. It is the hot-cold cycle of driving in the winter that does is and the results are not just milky. It is more of a creamy paste . .. . not really liquid. Very nasty stuff.

BTW. . . where is the "factory catch can" on the Nox 3.6L ? I was understanding that there was just a hose on each valve cover and the one on the rear with the PCV valve went straight to the intake manifold under the plactic engine cover.
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

And to further add, the 3.6 LFX V6 uses an external designed PCV system. Where the low side PCV hose is external to the engine and can be tapped into for adding the aftermarket oil catch can.
Apparently the 2.4 4 cylinder uses an internal designed PCV system. There is no low side hose available to be tapped into. It's more complicated to try to add an oil catch can to this 4 cylinder (but not impossible).
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Chas- the 1 cup you mention....
makes sense.. as the amount of oil that is lost in about 5000 mile OCI on my Traverse...
 

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Discussion Starter #66
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Chas said:
GM does not install any catch can on the low side of the PCV system. GM only installed a "catch can" on the high side of the PCV. The aftermarket catch can I installed is on the low side of the PCV system.
But there are also other pictures showing severe carbon deposits on the intake valves. Who's right? I don't know.

Because I don't know, I prefer to be safe and installed the aftermarket PCV oil catch can. This aftermarket oil catch can is installed on the low side of the PCV system (where there is not any installed by GM). This low side PCV oil catch can fills up much faster than the OEM high side oil catch can. I don't have measurements, but my estimate would be about 1 cup of oil/moisture vapors filtered out every 3k miles.

Maybe GM really does have the direct fuel injection timing optimized to wash the intake valves while it's open during run time. And the aftermarket catch can is capturing gunk that would be washed away anyway. Or maybe the timing is not sufficient, and carbon deposits build on the intake valves. It is strictly my opinion: the intake valve is not physcially opened far enough for long enough for the fuel injectors to sufficiently keep washing it clean. Again, IMO: the oil catch can significantly reduces the amount of deposits the fuel injectors would need to wash off the valves.

I'm quite meticulous like rbarrios is with his 'Nox. Perhaps we'll make a good comparison at 100k miles. If by then we're both willing to open up our intakes, we can take a look at the valves to see if my oil catch can made any difference. Maybe it did, maybe not. If not, I just blew $150. (IMO, not a big deal considering what I might be protecting.) :shrug:
Thanks for this write up and I agree. I do not know either. But I have spent more that I did on the catch can for stuff that doesn't matter. So I look at it as good insurance. Plus, as I said, in colder climes the sticky stuff is even worse. I sure want to prevent as much of the goo as possible from getting into the intake maifold and baking onto the back side of valves.
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

JayTee2014 said:
where is the "factory catch can" on the Nox 3.6L ?
see the little reservoir attached to the air filter to TB tube.....by the PS cap.... hose connected to it,.



These are the amounts im removing from mine after 7,000 miles.
I stick the paper towel in there-- and as you can see- its not much.



 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

JayTee2014 said:
Thanks for this write up and I agree. I do not know either. But I have spent more that I did on the catch can for stuff that doesn't matter. So I look at it as good insurance. Plus, as I said, in colder climes the sticky stuff is even worse. I sure want to prevent as much as the goo from getting into the intake maifold and baking onto the back side of valves.
Yes I have seen images of the goo-- that looks more like Foam...
 

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Discussion Starter #69
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Chas said:
And there is a PCV valve in the low side system that regulates the PCV flow. For simplicity's sake, I left out that valve.
But apparently, this PCV valve orifice is a little too small for the direct injection engine. There are mods for drilling out the holes a little more to help with the crankcase excavation. I think I saw somewhere it was a design change implemented for 2015. So I might do this mod myself for my 2013.

*Do not mix the low side and high side of the PCV system. There are some who think to add a "T" to tie both hoses together. If you understood how the system works, you'll realize connecting the high and low side hoses will defeat the purpose of the PCV system!
+1 I thoroughly understand how the PCV system works. What is interesting is, that I owned several cars in the past BEFORE they ever had PCV valves. On a 1955 Olds with the 324 V8, there was just a an oil filler neck on the front of the engine timing chain cover. Back then, the oil filer cap was also a vent with just a baffle in it to let the vapors go into the atmosphere. Well, after an engine got older and developed more blow by, oil under blow by pressure and helped along by the spinning timing chain just below the filler neck , would literally "fling" up the neck and out through the top of the baffled filler cap. The oil would spray all over the under side of the hood and spread even more because of the radiator fan.

I got tired of that, and just like the Elite Catch Can, I shoved a Brasso kitchen scrubbing pad down the filler tube neck. It would not fall into the timing chain, because there was a wire grid down at the bottom of the filler neck tube. The Brasso pad, would collect the oil and let it drain back down into the engine timing chain area. I guess I should have patented my "Brasso" pad fix. ;D ;D
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

rbarrios, great pictures! I hope you don't mind me using one of your pictures to help illustrate the different High vs Low side PCV hoses attached to this post.
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

JayTee2014 said:
I got tired of that, and just like the Elite Catch Can, I shoved a Brasso kitchen scrubbing pad down the filler tube neck. It would not fall into the timing chain, because there was a wire grid down at the bottom of the filler neck tube. The Brasso pad, would collect the oil and let it drain back down into the engine timing chain area. I guess I should have patented my "Brasso" pad fix. ;D ;D
Would have been a millionaire by the 80's. Oh man... :thumb:
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

hey jaytee,

i know this is off topic, but did the olds have a clear jar sitting on the motor???? my uncle had a 50's olds that was his mothers, and it had a say a small or medium sized clear glass jar that sat near the top of the motor. he would always joke thats the hiding place for the shine she would stash when she was younger!! :beer:
 

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Discussion Starter #73
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

kb3tzt said:
hey jaytee,

i know this is off topic, but did the olds have a clear jar sitting on the motor???? my uncle had a 50's olds that was his mothers, and it had a say a small or medium sized clear glass jar that sat near the top of the motor. he would always joke thats the hiding place for the shine she would stash when she was younger!! :beer:
Hmmm .. . . I do not recall that, unless it was the fuel filter? They used to use glass bowl fuel filters with a brass screen inside them. The glass bowl sometimes connected next to or a short distance away from the carburetor. The glass had a retaining ring across the bottom which held it sealed to the upper metal top. They often started to leak. You could disassemble it and clean any debris that got trapped. Many times, though, after years the brass screen got corroded to the point where it fell apart and was useless. By that time, cheap disposable in line fuel filters became available and the glass filter was bypassed and sat there empty or removed all together.
 

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Discussion Starter #74
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

rbarrios said:
see the little reservoir attached to the air filter to TB tube.....by the PS cap.... hose connected to it,.
Thanks very much for pointing out the high side vent line to the air cleaner. That seems to have collected some alright and a lot of moisture.

As Chas pointed out, it is the low side that goes directly to the intake manifold that really gets quite a bit. The "can" or plastic reservoir supplies filtered air into one valve cover and circulates this air into that valve cover and crankcase, while the "low side" connected to the intake manifold, then draws the now oil contaminated air into the engine intake and then burns it via combustion. The trouble is, along that path the oil vapor and any water vapor, has a chance to cool down and condense. So much of it never gets burned but coats the inside of the intake manifold and then bakes on the back side of the intake valves.

This was not too much of an issue with port fuel injection where detergents in gasoline would "wash" the back side of intake valves and keep them relatively clean. Now, with DI engines, little to no gas and therefore cleansing detergents, get routed to the back side of intake valves.


BTW, we have 57 mixed miles on the Equinox after going out to eat after delivery to us. Showing 20.7 best average mpg. The traveled distance was about 40% urban stop and go and 60% semi rural 40 to 60 mph driving, with an occasional stop sign. Tomorrow, we are going on a 170 mile round trip to the city along with maybe 20 miles of stop and go urban driving while there. We will see what mpg shows when we get back.
 

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Discussion Starter #75
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Here are hopefully two videos very early this morning after replacing all the dome and map lights with LEDs and the backup lights with LEDS.

The second video doesn't do justice to the increased brightness and clarity of the LED backup bulb. The LED is on the Right and I left the standard bulb in the Left side for comparison. Also, a rear cargo view of the interior after the LEDs were installed.
*

http://vid1055.photobucket.com/albums/s503/Alero1956/VID00137_zpsunwwaz3a.mp4
*
http://vid1055.photobucket.com/albums/s503/Alero1956/VID00138_zps404i1vfs.mp4
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Nah you can see a difference. I noticed you had the courtesy lights at the footwell... but they didnt look led bright. Did you change them too or not yet?.
 

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Discussion Starter #77
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Davek said:
Nah you can see a difference. I noticed you had the courtesy lights at the footwell... but they didnt look led bright. Did you change them too or not yet?.
Good eyes! Dave. . . it is 20 degrees in my garage and these old fingers and hands only last so long in the cold. :thumb:

But I will be changing them out. BTW, I found a good way to extract those 194 bulbs. A piece of rubber hose with about 3/8" ID slipped over the bulb a bit grips it really well. Just slid it over gently a bit and pinch it and pull. You don't want to push too much or too hard on the 194 while it is in the socket, else like on my truck, the socket will unlatch from the lamp fixture and then you have more work taking off the bezel for whatever light you are working one to clip the socket back in. Guess how I know this? ;D
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Good tip.. :thumb: I have a pair of needle nose and did almost the same thing I put rubber hose on each side.. well vacuum hose to grip little bulbs without breaking them to remove and install them. This way I can get different types and sizes for as wide as they open. Hey my garage at homhome is full so if it were that much of an emergency to do something at home that to drag it to the shop I would have to do it outside. Why not get a Q mark heater for the garage.. and I am sure you could handle wiring up to the electrical pannel. Or get a kerosene heater.. I know the smell at times stinks.. but warm up the gage and shut it off while out there working. I just got my courtesy lights for the Terrain yesterday. This weekend if time permits I will put them in.. probably 15 mins of work.
 

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Discussion Starter #79
Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Some interesting mpg figures on the first two outings in the Equinox.

Last night we drove 57 mixed miles in the Equinox after going out to eat after delivery to us. Showing 20.7 best average mpg. The traveled distance was about 40% urban stop and go and 60% semi rural 40 to 60 mph driving, with an occasional stop sign. Tomorrow, we are going on a 170 mile round trip to the city along with maybe 20 miles of stop and go urban driving while there. We will see what mpg shows when we get back.

Well, on the first leg of our trip today which was 62 miles of rural two lane highway and later some semi urban driving together with the 57 miles last night here is what we have on the DIC. We drove between 55 and 60 mph during today's 62 mile trip. There were 7 stops sign along this route to boot. Here is what the DIC showed after the two trips so far:
 

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Re: 2015 Equinox LTZ 3.6L Just Ordered 12-18-2014

Oh, JayTee2014, no matter what pictures you post, some people here won't believe the 3.6 can get much better than 24 mpg.
But I believe you, and I know it's gonna get better after break in and wear in. :)
 
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