re: GM's 6.2 & 5.3: Sudden Engine Failure

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often attributed to manufacturing defects and the use of cylinder deactivation technology (Dynamic Fuel Management)

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Why is this now causing issue? I had a 2008 Silverado in college that was the first year they had the cylinder deactivation and I don’t remember those year models having any issues. Drove that truck 225k miles, and many were rough miles.

You’d think 17 years would improve the technology

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All lifters have a finite life. Yes some last longer than others.

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True, but AFM lifters can be especially short.

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The problem with afm lifters is they collapse to go in 4 cylinder mode and don't expand again leaving an undersized lifter.

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Generally, yes, but the failure mode is a pin that wears and sticks and causes the sticking condition. Generally, the more often the system cycles, the sooner it will fail.

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The c7 corvettes with manual transmissions don't seem to have these issues because you have to put it in eco mode for the afm to engage.

The c7 automatics will go into afm unless you are shifting manually with the paddle shifters and according to vette forums have a lot more lifter issues than the manual cars.

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I own a C7 Z06 in Auto. Yes the manual cars tend to experience fewer failures, again, due to lack of the system cycling.

So you can likely extend the time before failure by using a device that stops the system from cycling, or turn it off in tuning.

But yes, it is ultimately borrowed time on those lifter failing (mch sooner than a non-AFM lifter would)

Absolutely! Even better if they would install them in a half ton!