Its the AFM in their V8’s thats scary… No idea what the percentage of their engines have had problems yet theres a lot of articles and videos on it.
Reference site autocornerd.com
”In 2019-2021 (March) Chevy vehicles, AFM lifters had gone even worse that the vehicles seem to be failing under 10,000 miles.
One user says this:
“6,272 miles on my 2021 Trail Boss and it’s in with a failed lifter right now. Seems a bit early for this type of major failure.”
Another user says this:
“2020 Silverado 5.3- Knocking, check engine (emissions warning), Service ECS, parking brake. Took it in this morning and haven’t gotten the official diagnosis yet, but the technician said this combination sounds like lifter failure. I bought the truck several months ago with 8k
And from site pickuptalk.com:
“General Motors V-8 engines are no stranger to lifter problems. Owners of GM V-8 engines with Active Fuel Management (AFM) have dealt with stuck and collapsed lifters for years. But it seems a new round of lifter woes are hitting GM truck engines with relatively low mileage.
The GM lifter problems affect both the 2019-2021 Chevrolet Silverado and GMC Sierra pickups as well as their GMT T1XX platform SUV siblings, the Chevrolet Tahoe, Chevrolet Suburban, GMC Yukon and Cadillac Escalade.
“On the older trucks, you would see issues around the 50-100k range, whereas a lot of the new trucks’ failures are in the 4-digit mileage range,” said a dealership technician who wishes to remain anonymous. “We are seeing about one every other week, and just last week had three towed in on one day.”
(End of quoted articles)
These are just two website examples. Not saying GM has a Ferd 6.0 or 6.4 black eye from this yet I for one wouldn't want to own one without a long GM extended warranty.