Originally Posted by JayT2014
I'm thinking a lot of it (maybe not all) has to do with how attentive an owner is with reasonable OCI of say, 5K to 6K miles plus keeping on top of other maintenance like TB cleaning, air filters, etc. That and driving style, as well as ,yes, highway miles are generally easier on an engine.
Read the tsb. You're close, the cause is due to the piston rings retaining the same design and durability from when this same engine design was used in non direct injection applications. In the direct injection application the rings do not receive the same lubrication and wear more quickly allowing blow by, and should have been made out of tougher stuff.
I think you are right that people who go beyond what is required on oil changes or use their vehicle very lightly may not have this problem occur at a low mileage. However, I take the opposite inference and see this as a bad result, because those people are not getting the defective rings replaced. GM has admitted this component is defective in this application - they are bound to fail sooner or later and cause oil consumption. Perhaps a time bomb for the secondary market owner buying out of warranty.
Personally, If I had one that had not been repaired, I would change the oil only by the OLM, and drive the car hard until it started consuming oil so I could get the repair. If I were buying a used 2010-13, I would insist on buying one that received this repair.
"Piston Ring Coating
The top compression ring in the new kit has a more robust coating on it that is designed not to wear as quickly as the original coating. Tests indicate that it wears about 4-5 times longer than the original coating.
If the top compression ring is worn, it will allow combustion pressure past it, which causes the oil control rings to be less effective and results in excessive oil consumption.
On 2010-2011 vehicles built before March 2011, there is a strong correlation between leaking high pressure fuel pumps diluting the oil and causing the ring wear. Due to this, check the fuel pump, balance chain, balance chain tensioner and timing chain for the proper part numbers. The updated fuel pump has an enhanced seal.
If these updated parts have not been installed during a previous repair, they should be replaced when the pistons and rings are replaced. Use field action #12313 if the balance chain and/or fuel pump is replaced."