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DiscoStudd

3.6 LFX Oil Catch Can installation

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It's definitely condensation.  The coolant level is spot-on and the oil is nice and coolant-free.  No yogurt on the bottom of the 710 cap either!

Knock on wood, but damn, it would be a hellacious nightmare if a headgasket were to pop on that 3.6!

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What problem does that catch-can solve?

Without it, that condensation + traces of hydrocarbon goes harmlessly through the engine and out the tailpipe, just as it does on millions of other engines.

I didn't watch the entire video--I gave 'em both the "5-second fast-forward" over and over, so 15 minutes of video cost me about two minutes of my life.

Oxidizing hydrocarbons (burnt fuel) results in a shipload of water.  Hydrogen + Oxygen = what?

It's no surprise that water vapor collects in the crankcase as the result of blowby.  Everyone else uses a simple PCV system to eliminate it, you've added complexity and expense plus another maintenance item where it's not needed and does no good.

Edited by Schurkey

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Do a Google search for carbon buildup on GDI engines.  Also lookup "Alloytec Carbon Buildup."  BMW, VW, Ford, Toyota, GM, and Mopar, have all experienced carbon buildup on their early direct injection engines (Ecoboosts and Pentastars are the worst offenders.)  The LFX in my car isn't as notorious as the older LLT's in the Camaro and Traverse were for carbon buildup, but search any Camaro forum and there are pages upon pages of boroscopic proof of the GDI carbon buildup on the V6's.

As much as I despise Toyota, they came up with the best solution with their GDI engines.  They started putting port injectors in their GDI engines to wash the deposits off of the intake valves.

Your old pushrod, port-injected GM V6 will never have this problem, nor have any need for a catch can...

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Further education on the topic:

 

 

 

I understand how you'd not be informed of this issue, as I thought I was the last person on earth who was clinging desperately to his pushrod-powered GM vehicles well past the time the rest of the world moved onto OHC engines with DI.  I didn't really hear of this issue myself until after I purchased 2 GDI powered vehicles.  

 

Like I mentioned in my video, when the weather turns warm up here in the frozen tundra, I will be pulling my upper intake and running a scope down the intake ports to see how bad the carbon buildup is.  I hope I won't need to resort to walnut shell blasting, so I will try my damnest to clean the deposits out with a brush set and a thorough soaking of B12 Chemtool.

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Fine.  I'll ask again:

How does removing water condensation from the PCV system have any effect on carbon buildup in the intake system? The little amount of sludgy hydrocarbon you've trapped in the catch-can is so minor that it wouldn't have any noticeable effect on the valve deposits.

Far as I know, the carbon buildup on the valves and intake tract is from reversion, and from the EGR system, if used...not the PCV system.

I still say this is a total waste of effort.

Edited by Schurkey

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If one wants to stave off the carbon buildup on the backside of the the valves change your engine oil more often, if you're relying on that silly oil life monitor then do not. Regardless if using mineral based or synthetic keep the oil cleaner, that will reduce the buildup, it will not eliminate the problem but will help lessen it.

 

or like me....don't purchase any vehicle that makes use of a GDI engine, until this issue has been eliminated entirely.

I personally don't relish the idea of pulling my intake system every 40,000kms (not miles)  just to clean valves.

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On ‎12‎/‎3‎/‎2018 at 7:15 PM, 55trucker said:

If one wants to stave off the carbon buildup on the backside of the the valves change your engine oil more often, if you're relying on that silly oil life monitor then do not. Regardless if using mineral based or synthetic keep the oil cleaner, that will reduce the buildup, it will not eliminate the problem but will help lessen it.

I have to disagree here.  The problem is actually caused largely by changing oil too often, and tends to hit enthusiasts and those who 'religously' maintain their cars far more frequently than those who little maintenance (cars that adhere to the maintenance minders basically don't seem to have the problems!).  The first thousand or two miles of virgin motor oil has the greatest amount of volatilization from the lubricant as it is essentially distilled under vacuum in the crankcase.  With the distillate going into the intake through the PCV, creating the deposits.  So if you minimize the use of fresh lubricant, there is less deposit-causing material to be distilled from the lubricant, and hence, fewer intake valve deposits.  

So engines with the GDI problems absolutely scream for long drain intervals and the best quality synthetic oil money can buy (which may or may not be the most expensive).   

Of course, one doesn't want to run the lubricant so long that it loses its lubricating properties.  But the GM 60-degree V6 NA engines tend to be extremely easy on oil, and drain intervals, such as my 92k km's / 57k mile to date interval with proper top-ups and filter changes can keep intake deposits to a minimum.  

Edited by pitzel

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On ‎11‎/‎26‎/‎2018 at 8:57 PM, DiscoStudd said:

It's definitely condensation.  The coolant level is spot-on and the oil is nice and coolant-free.  No yogurt on the bottom of the 710 cap either!

Knock on wood, but damn, it would be a hellacious nightmare if a headgasket were to pop on that 3.6!

When did you change oil last?  

Any possibility of, for example, in the summer months, driving for a month, checking the catchcan.  And then driving the next month, for a relatively similar distance/time, and then checking the catchcan again?

I highly suspect the GDI intake problems are largely due to "enthusiasts", and people who think they know better than the manufacturers, doing oil changes far too frequently.  

So if you collect a much lower quantity of fluid on the 2nd (summer) month of catchcan use, after an initial oil change, that would go towards proving that theory, that its the extra oil changes that enthusiasts often do, that is significantly at the root of the GDI intake issues.  

Just as an anecdote, I acquired the vehicle in the tagline from an old man who had his oil changed at Wal-Mart with the cheapest 5W-30 they offer every 1000-1500 miles, basically 4X a year.  The throttle body and intake plenum was absolutely filthy with caked on motor oil.  Requiring solvents for cleaning.  Changed to a high quality synthetic on very long oil change intervals, and every time I've inspected it since, the little bit of oil that's present is easily wiped away with a rag.  

Edited by pitzel

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If that concerned about deposits on a di motor then take it to your local dealership and have them run a induction cleaning "fogger" every so often as maintenence or be one of those people on youtube and get a can of seafoam and do it yourself

Sent from my SM-N900T using Tapatalk

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