Interesting info from King Bearing linked below. If you somewhat read between the lines, there are a few things that appear to stand out.
1. Hot Short - Might be a bit far fetched on these engine under daily driving conditions, but think about it of you understand a Hot Short condition. This has been found associated with NASCAR and other racing series where the engine has been shut down when very hot due to a red light/flag condition to stop the cars mid race for some reason and the bearings heat soak and the material becomes soft. Then restarting the engine with the bearings hot and possibly soft can cause either immediate damage or partial damage that can be seen when the engine is torn down after the race.
While this comparison is not as severe, think about all the Auto Stop/Start conditions and the possibility of Hot Short conditions or partial Hot Short condition that could possibly occur. Or continually having the Stop/Start function active how this could impact bearings with partially dry starting conditions. Add the 0W20 oil that may not hold a film on the bearing surfaces so well when hot. The fact that the vane style oil pumps loose their prime quickly, This may cause bearing degradation over time and not cause an immediate failure. Turning off or disabling the Auto Stop/Start feature may help this condition? Is the Stop/Start feature a contributor, who knows for sure? Maybe it is a problem if the bearings start to fatigue as outlined below?
2. Bearing Fatigue - Could be due to Detonation/Low Speed Pre Ignition, High Torque/Low RPM operation which is pretty typical with these engine designs these days along with the 0W20 engine oil. Also keep in mind that there could be one or more fuel injectors that may not operate properly that could cause a LSPI condition in one or just a few cylinders. I do not think the LSPI really manifests itself into a misfire condition or knock condition that the ECU can pick up on. Wonder if the DFM could also put more stress and fatigue on bearings when dropping cylinders out and making the operational cylinder(s) work a bit harder for short periods of time.
Adding in fuel dilution of the oil, water contamination, extended oil changes all do not help the oil situation. Installation of of catch can can help reduce some of this problem as well.
Curious if the Trailer Towing packages help with extra cooling of the engine and/or engine oil may help prolong the engine life and/or reduce some of these premature failures?
At the end if the day, the majority of these engine failures can be classified as oil related failures in some form or another. The 6.2l has a 2 stage oil pump that may or may not be contributing to its early demise. If I had my way and I may look into it, forcing the oil pump into the higher pressure stage might be a good thing. Either damage due to improper lubrication, not enough oil in the right place at the right time, contaminated oil, or some form of bearing overloading.
While GM claimed at one point that oversized lifter bores were the cause of some failures, not sure if this was more a cause of lifter failures, bearing failures or both. I wonder how oversized the lifter bores actually were? Enough to starve the main and rod bearings of oil? The oiling path on these engines is not ideal, but it seems back as far as the 6.0l non AFM/DFM engines had a similar oil path without the level of problems. Even the current 5.3l does not seem to have the level of problems the 6.2l is having, only obvious this between these engines is the 2 stage oil pump that I have found.
Just a few thoughts.
