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Discussion Starter · #1 ·
With all this valve cover talk i remembered a very important point.
Ebay catch cans do not have the required flow volume that our PCV system requires.

With this said if you install a restrictive catch can onto a healthy cruze you can blow out the Orange PCV change valve, then it will literally push oil into your catch can filling it in minutes insead of weeks.

If you want a catch can to grab oil mist, please look at a high flow setup like Ultimate Oil Catch Can - 42 Draft Designs
just paid $350 Canadian pesos for this guy but it doesn't restrict air flow on our PCV systems.

Cheapest i could find that flowed enough air...
 

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Why do you have a catch can in the first place? There's no need for it, at all. The oil separator in the valve cover does a fantastic job.

The orange nipple doesn't blow out because of a catch can. It blows out on factory cars because it's a **** design that GM should be ashamed of. It's supposed to open up under vacuum, all you're doing is forcing it open under boost.

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For the record, my first oil change with AMSOIL went 15,622 miles with no measurable oil loss. I didn't top off once. If I'm not losing any oil, what good will a catch can do?

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Its mainly meant for performance and not oil loss. Oil vapor that reaches the combustion chamber causes carbon buildup and can lead to preignition and detonation.
 

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Its mainly meant for performance and not oil loss. Oil vapor that reaches the combustion chamber causes carbon buildup and can lead to preignition and detonation.
Yes, theoretically, but in such small volumes that it is absolutely negligible. What is theoretical may not exist in the real world when actual quantity or volume is considered. I could see this if I was burning a quart every 2k miles but that's not the case with a properly working Gen1 1.4T. Furthermore, the fuel also cleans the piston and combustion chamber, and any deposits accumulated can be remedied with the regular use of a top end cleaner, which you should be using anyway. The catch can doesn't stop oil vapor from getting into the intake when the engine is operating under vacuum anyway and even top tier fuel isn't 100% effective at preventing deposits.

The catch can only catches anything when the engine is under boost. Under vacuum, the check valve in the intake manifold opens.

On a properly functioning engine, using a low volatility synthetic oil, you will have immeasurable levels of oil consumption that all effectively eliminate the need for or benefit of a catch can.

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I was just saying that that's the intended purpose of a catch can. You could run 2 catch cans which wouldn't restrict airflow.
 

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I understand the theoretical purpose, but it simply doesn't apply to this engine and doesn't even filter all PCV gas due to the design. It's useless, and the only people that catch any oil in these in the 1.4 have other PCV related issues that they aren't addressing.

Two catch cans double the cost and take up twice as much space. You would have a cleaner engine buying three cases of top end cleaner additives and running a bottle every 5k miles than running two catch cans.

They have their place, but I've yet to see a single valid reason to use one in the Cruze.
 

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I understand the theoretical purpose, but it simply doesn't apply to this engine and doesn't even filter all PCV gas due to the design. It's useless, and the only people that catch any oil in these in the 1.4 have other PCV related issues that they aren't addressing.

Two catch cans double the cost and take up twice as much space. You would have a cleaner engine buying three cases of top end cleaner additives and running a bottle every 5k miles than running two catch cans.

They have their place, but I've yet to see a single valid reason to use one in the Cruze.
Seafoam is $8 for one can and the eBay catch can is $15. $30 once vs $8 every other oil change. I'd prefer less maintenance.
 

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Seafoam is $8 for one can and the eBay catch can is $15. $30 once vs $8 every other oil change. I'd prefer less maintenance.
I assumed one was talking about a GOOD baffled catch can, not an ebay special from China.

I also assumed you would have remembered that the PCV system bypasses the catch can (and there is no possible way to change that) when the engine is operating under vacuum (90% of the time).

I know you have a Gen2, but there's a nice explanation and diagram in the Gen1 powertrain section in the 1.4T sub-forum explaining the PCV routing of this particular engine. A catch can is a waste of time and money in the Gen1 1.4L Turbo, and I'm not holding my breath that the design is substantially different in the Gen2 with respect to PCV routing under intake vacuum.
 

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Discussion Starter · #11 ·
XR you have a very different driving style, and your not running insane levels of boost. I've been moving oil since i installed the trifecta tune at 5000 miles. It was droplets in the intake, after hard track days, getting the oil over 200C. The volatility absolutely comes into play. Mobile one 5-30w is what i've been running, i have no doubt that amsoil would not mist up as easily. I dont use a catch can for performance, its a such a slow amount of oil making to through the PCV it wouldn't give you detonation. (Unless PCV system failure then it will cause detonation!)

I use the catch can to catch oil cause i get a quart an oil change in the intake. To say that it doesn't happen on a healthy cruze is ridiculous even with amsoil. I can see if your eco driving any cruze it won't move oil, but once you start heating up the oil and running 22+ psi boost the story changes.


I'll do this XR, I'll measure how much i catch with M1, and change it to Amsoil for 2 oil changes, and compare collection difference.

Also lots of cruze owners run catch cans, you should know this as MOD of Cruze talk. And yes you will argue that their PCV systems aren't working properly. But i know that mine and other High output cruzes do have their PCV systems in working order and have pulled their hair out over many nights trying to figure out why they get oil droplets pooling in the throttle body. In a track day i can fill the catch can, a cold month in winter i wont move a drop...

See various catch can cruzes below
2011 Holden Cruze SRIV – Elite Cruzes
 

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Discussion Starter · #12 ·
Which amsoil will have the lowest volatility, which would you recommend for my catch can test. (If it doesn't fill the can at all i'll buy you a beer)
 

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XR you have a very different driving style, and your not running insane levels of boost. I've been moving oil since i installed the trifecta tune at 5000 miles. It was droplets in the intake, after hard track days, getting the oil over 200C. The volatility absolutely comes into play. Mobile one 5-30w is what i've been running, i have no doubt that amsoil would not mist up as easily. I dont use a catch can for performance, its a such a slow amount of oil making to through the PCV it wouldn't give you detonation. (Unless PCV system failure then it will cause detonation!)

I use the catch can to catch oil cause i get a quart an oil change in the intake. To say that it doesn't happen on a healthy cruze is ridiculous even with amsoil. I can see if your eco driving any cruze it won't move oil, but once you start heating up the oil and running 22+ psi boost the story changes.


I'll do this XR, I'll measure how much i catch with M1, and change it to Amsoil for 2 oil changes, and compare collection difference.

Also lots of cruze owners run catch cans, you should know this as MOD of Cruze talk. And yes you will argue that their PCV systems aren't working properly. But i know that mine and other High output cruzes do have their PCV systems in working order and have pulled their hair out over many nights trying to figure out why they get oil droplets pooling in the throttle body. In a track day i can fill the catch can, a cold month in winter i wont move a drop...

See various catch can cruzes below
2011 Holden Cruze SRIV – Elite Cruzes
Let's see, driving style. The 15,622 mile run (which you can see an analysis of in the 1.4T subforum of Powertrain), had:
- WOT runs for datalogging and testing various Trifecta tunes
- Several hundred WOT runs for datalogging BNR tunes
- Short trips and constant runs to redline

I've towed my 14 foot boat to the lake and back 2-3 days a week for all of summer and fall for the last 2 years. I occasionally tow a 5x8 uhaul trailer, have towed a 5x9 open trailer, and on some occasions towed a fully loaded trailer (estimate about 1500-2000 pounds) against a moderate headwind for an hour straight, sustaining 3-4psi of boost for minutes on end on perfectly flat road.

The engine hits redline every time I go out, and sustains levels of boost for extended periods.

Now, I'm not hitting the same boost levels you are, partly because I can make more power at lower boost levels with my BNR tune than I did with the Trifecta tune I had before it, but the point I'm making is that my vehicle operates in boost for substantially more of my driving than your average Cruze owner.

Now, you know how much oil I had to add during that 15,622 mile run? Absolutely none. I put 4.75 quarts in the engine when I filled it up to barely pass the full mark, and I did not add anything until I drained it, even when I replaced the filter at 7,500 miles. With a PROPERLY functioning Cruze, even under hard tuned driving conditions, the engine will not consume a measurable amount of oil. Maybe it's the oil I'm using and the fact that it remains stable and maintains its volatility and thermo-oxidation specifications throughout its service life; I couldn't tell you since nobody can afford to send oil out for those kinds of tests. I'm on my 3rd change with AMSOIL Signature Series. First was 15,622, second was 8,255 (dealer drained it when they replaced the oil pan gasket), and the current run has about 6,500 miles on it. I will repeat, I have never had to add oil to my engine.

Now, I will acknowledge that even I find oil droplets pooling in the throttle body, and I will maintain that there exists some amount of seepage at the turbo seals, but that the actual amount of oil being ingested by the engine is, for practical purposes, inconsequential.

Please don't take my response as accusatory or attacking; my technical responses are always blunt and the tone can sometimes be perceived as abrasive. Just assume you're listening to Spock. I present what I believe to be the facts. Doesn't mean I can't be wrong.

Which amsoil will have the lowest volatility, which would you recommend for my catch can test. (If it doesn't fill the can at all i'll buy you a beer)
AMSOIL Signature Series 10W-30 has the lowest volatility, if you do not plan to operate at temperatures under 0F (-17c). Since you're in Canada, however, I would expect you to need a 5W-30, if not a 0W-30.

AMSOIL Signature Series 5W-30 has a NOACK volatility of 7.5%, and the 0W-30 comes in at 8.4%. Both are lower than Mobil 1's (assuming you aren't using EP, and are at 5W-30) 10.1%.

Conveniently, there's an AMSOIL distribution center in Edmonton, at 14328-121A Ave. Edmonton, AB T5L 2T2. Shoot me a PM, and for this specific occasion, I'll get you wholesale pricing on it. If you don't see a reduction in oil in your catch can, I owe you a beer.
 

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I assumed one was talking about a GOOD baffled catch can, not an ebay special from China.

I also assumed you would have remembered that the PCV system bypasses the catch can (and there is no possible way to change that) when the engine is operating under vacuum (90% of the time).

I know you have a Gen2, but there's a nice explanation and diagram in the Gen1 powertrain section in the 1.4T sub-forum explaining the PCV routing of this particular engine. A catch can is a waste of time and money in the Gen1 1.4L Turbo, and I'm not holding my breath that the design is substantially different in the Gen2 with respect to PCV routing under intake vacuum.

When is any engine in vacuum 90% of the time? Maybe if you have a very light foot but I think most Cruze 1.4t with automatic transmissions drivers are in boost at least 50% of the time. It doesn't take much to get into boost. The turbo spools quicker with an auto than a manual.
 

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When is any engine in vacuum 90% of the time? Maybe if you have a very light foot but I think most Cruze 1.4t with automatic transmissions drivers are in boost at least 50% of the time. It doesn't take much to get into boost. The turbo spools quicker with an auto than a manual.
I've noticed Cruzing around 65-75mph it for sure gets near atmospheric on the light rolling bumps on our relatively flat road ways, if not 1-2 psi gauge pressure.
 

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When is any engine in vacuum 90% of the time? Maybe if you have a very light foot but I think most Cruze 1.4t with automatic transmissions drivers are in boost at least 50% of the time. It doesn't take much to get into boost. The turbo spools quicker with an auto than a manual.
Go datalog your Cruze with something and tell me how much time you spend above atmospheric pressure. Trust me, it's a lot less than you think. Cruising straight on the highway, you will be pulling a vacuum.

The only time the Cruze is producing boost is when going up a hill and when accelerating. However, you are pulling a vacuum when decelerating and going down a hill, so at best, you are using boost 50% of the time if your driving is 100% hilly and stop/go without maintaining speed at any point or ever stopping at a traffic light. I'd be willing to bet that you, and anyone else around here, spends more time maintaining speed or waiting for a light to change than they do accelerating and decelerating.

Exceptions include driving against a headwind or over standing water and snow.
 

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Go datalog your Cruze with something and tell me how much time you spend above atmospheric pressure. Trust me, it's a lot less than you think. Cruising straight on the highway, you will be pulling a vacuum.

The only time the Cruze is producing boost is when going up a hill and when accelerating. However, you are pulling a vacuum when decelerating and going down a hill, so at best, you are using boost 50% of the time if your driving is 100% hilly and stop/go without maintaining speed at any point or ever stopping at a traffic light. I'd be willing to bet that you, and anyone else around here, spends more time maintaining speed or waiting for a light to change than they do accelerating and decelerating.

Exceptions include driving against a headwind or over standing water and snow.
I live in Missouri and I'd say about 50% of my driving is highway but it's hilly everywhere I drive. You can't just throw out a bogus stat just to better your chances of people believing you. Sooner or later you're going to lose credibility. I have datalogged my daily commute and I average just above atmospheric pressure in the intake manifold even driving like a grandma. This is with the cruise set at 60mph 80% of the way to work. It's only a 25-30 minute commute. Your statistics are in the idealist of conditions which is not real world for most.
 

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I live in Missouri and I'd say about 50% of my driving is highway but it's hilly everywhere I drive. You can't just throw out a bogus stat just to better your chances of people believing you. Sooner or later you're going to lose credibility. I have datalogged my daily commute and I average just above atmospheric pressure in the intake manifold even driving like a grandma. This is with the cruise set at 60mph 80% of the way to work. It's only a 25-30 minute commute. Your statistics are in the idealist of conditions which is not real world for most.

If I have been reading all of this correctly, unless you tend to accelerate down hill a lot, it is still 50/50 at best.
 

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I live in Missouri and I'd say about 50% of my driving is highway but it's hilly everywhere I drive. You can't just throw out a bogus stat just to better your chances of people believing you. Sooner or later you're going to lose credibility. I have datalogged my daily commute and I average just above atmospheric pressure in the intake manifold even driving like a grandma. This is with the cruise set at 60mph 80% of the way to work. It's only a 25-30 minute commute. Your statistics are in the idealist of conditions which is not real world for most.
What part of my last post was not clear to you? Assuming you are doing nothing but accelerating and decelerating, you are operating, at best, a 50/50 boost/vacuum ratio. Under cruise conditions on straight roads, the vehicle pulls a vacuum. A 1.4L Turbo, Direct Injected or otherwise, does not rely on boost to maintain speed on a flat road. Furthermore, the sheer number of Cruze owners that drive their cars in traffic conditions, where you are waiting for a light to turn red or waiting for the next car to move, indicates that for the duration of their trip, they spend far more time under vacuum than they do under boost.

Let's see that datalog that shows you average above atmospheric pressure while maintaining speed on flat roads.
 

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For the record, the context of this thread should have indicated that the actual percentage is not what's important. We're going to butt heads quite frequently if you're going to argue semantics out of context every time a noted data point disagrees with your personal experience. Whether it's 90%, 85%, 80%, or even 75% doesn't matter. It is a given that variances in driving conditions would mean that nobody could ever provide a specific, accurate number that applies to all driving conditions. That being said, the point of my statement, in context, was to note that the engine spends significantly more time under vacuum than it does under boost, and that the absence of that vacuum may not be inconsequential.
 
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