Carbon buildup in the DI engine

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[GoldEnclave]

The linked article supports my concern about unnecessary drivetrain wear and tear by revving the engine.

[TAZ427]

Very Interesting thread.  Questions for JRMarshal and XRDreamliner.

1.) Are your engines consuming a measurable amount off oil between changes - If so how much?
2.) Where your coil packs checked and fully working?

One of the things I'd be concerned about and would be higher likely to result in carbon deposits would be uncombusted fumes getting back into the intake - If there are bad coil packs (or even fouled plugs) this could result in a higher amount of carbon going back up the intake.

That said, the Alacran's pics of the really bad intakes show a line of oily build up down the intakes of the oily sludgy looking buildup.  The other cylinders look more like a traditional carbon build up, not what you want, but not really enough to impede airflow into the cylinder. 

The main issue w/ normal carbon (small amounts) build up on a TBI or PI engine is you want a smooth flow to keep the fuel atomized.  In a DI, you don't have a big issue w/ this as the atomized fuel is directly injected into the cylnder.  You just can't block the air flow, and the build up in the dirtiest one is enough to restrict the airflow a fair amount and reduce fuel efficiency.

I agree that that fuel additives are going to have little to no affect on the carbon build up on a DI engine.  I still buy fuel only from Top Tier providers, because you do get build up in the injectors and I think it's even more important in a DI engine to keep these clean than in a TBI or PI engine (both are very important to keep the injectors clean, but I feel DI it's even more important - that's just my humble opinion.)

The only source of a carbon is the blow by gases that's recirculated via the PCV.  Will fuel additivies help this, I doubt it.  I can't find the link now, maybe it was on the Traverse forum.  But the injecting of the cleaner into the Intake area sounds interesting, I wonder how effective this is.

[XRDreamliner]

Very Interesting thread.  Questions for JRMarshal and XRDreamliner.

1.) Are your engines consuming a measurable amount off oil between changes - If so how much?
2.) Where your coil packs checked and fully working?

1) No, my engine does not consume any oil between my 5K mile OCI's.
2) At 56k miles, I've not had any driveability issues to indicate the coil packs are bad.  The engine does not miss under load while going up hills in 6th gear, for example.

[TAZ427]

Did you happen to get pics of your valves?

[silvervettes]

One of the things I'd be concerned about and would be higher likely to result in carbon deposits would be uncombusted fumes getting back into the intake - If there are bad coil packs (or even fouled plugs) this could result in a higher amount of carbon going back up the intake.



It makes sense faulty coil paks could contribute to this. The paks can faulter intermittently too and then finally totally fail.  I had evidence of this in my 09.

 

[jrmarshall01]

I had two occasions for misfire....the first one about a year ago was deemed a "random misfire" by the code on the readout.  The second was a misfire in cylinders one and three.  Both misfires happened during a cold start and then abated. The check engine light came on in both instances.  I have had no misfires while driving (that I am aware of).  From one of the posts on this thread, I learned that valve carbon build up does manifest itself with cold start misfires, so I doubt that the coils were involved.  I can't answer your question directly about the condition of the coils, but I can tell you that nothing was said by the service people about them, nor was there any reference to coils on the work sheet.  As far as oil consumption...I have not been checking my oil levels often, but when I do, it seems full or just slightly below full.  I know I should do a better job checking, so I will report on this thread in the future if my oil levels are low between changes.   No pics of the valve heads have been taken.

[XRDreamliner]

BG now makes a specific 2-part carbon cleaner for DI engines (5th product down):

http://www.bgprod.com/products/fuelair2.html

[TAZ427]

BG now makes a specific 2-part carbon cleaner for DI engines (5th product down):

http://www.bgprod.com/products/fuelair2.html

Interesting, it's a two part cleaner.  I'd love to see the directions on how to use it.  I wondering if doesn't involve removing the intake manifold as it doesn't look to be something you'd simply suck into the intake.

[XRDreamliner]

I wondering if doesn't involve removing the intake manifold as it doesn't look to be something you'd simply suck into the intake.

Yes, to use the cleaner you need to remove the intake manifold.  The cleaner is meant to soak the carbon, so the intake valves need to be closed on the cylinder that is getting the treatment.

[DVelasco68]

Obviously this is not just an issue for the Lamada platform, those with Direct Injection Camaro's are using catch cans, and RX oil cap breathers to prevent oil from ever entering the intake:



http://www.camaro5.com/forums/showthread.php?t=238944



http://www.acadiaforum.net/index.php?topic=8789.msg194647#msg194647

[Suave1477]

I had a gas treatment performed at my local oil change place, so I assume that took care of anything that might be deposited in the engine.  They cleaned the area by the air filter where the oil seems to collect, (air intake?) then put something in the oil, and something in the gas tank and ran the vehicle on high idle for several minutes.  Supposed to clear out the system and push contaminants out the tail pipe.  Hopefully that has me set for a while.

If you dont mind me asking I am curious how much did they charge you for this?

Also I highly doubt as already explained numerous times on this thread that if you have carbon buildup the service performed did anything for it.