The small-block V8 behind the Silverado and Tahoe for two decades running — a genuinely tough bottom end paired with a fuel-saving feature that's also its most common complaint.
This engine family has one of the longest, most thoroughly documented track records of any V8 still in production — the core architecture is genuinely proven. The recurring complaint is Active Fuel Management (AFM, also called Displacement on Demand), which deactivates four cylinders under light load to save fuel: the lifters controlling that system are a well-known wear point, and oil consumption is a secondary, related complaint on affected examples.
Not a guarantee, but a pattern seen consistently across owner forums and independent-garage reporting.
First AFM lifter tapping noise and associated oil consumption on affected examples.
Lifter replacement or AFM-disable kits become a common proactive repair at this stage.
Non-AFM examples, or ones with the system proactively disabled, commonly continue well beyond this with no major work.
Listen for a ticking or tapping noise at idle, especially from a cold start — the clearest symptom of AFM lifter wear.
Check oil level and condition yourself if possible, since consumption on affected examples can outpace dashboard warnings.
Ask whether the truck has ever had an AFM-disable device installed — a popular, well-regarded preventative fix in the truck community.
Model-specific pages, with notes on how it behaves in that particular car.