Silverado 5.3 lifter tick and misfire: collapsed AFM lifters, what the noise means, and delete versus replace

A ticking V8 with a misfire on cylinder 1, 4, 6 or 7 is the signature of a collapsed cylinder-deactivation lifter. The choice after diagnosis is the real decision.

Active Fuel Management shuts off four cylinders under light load by collapsing their lifters. The lifters use a locking pin that wears and jams, so the lifter stays collapsed, the valve stops opening, and the cylinder misfires. Oil quality and long change intervals accelerate it.