Failure mode - Duramax 6.6L V8 Turbo Diesel (GM HD, LML 2011-2016; LGH vans 2011-2016)

Piezo injector failures / replacement economics (LML)

Reliability tier: aggregated - verify before ordering, see /disclosure/

Symptoms

injector balance/contribution codes, rough idle, fuel dilution of oil
hard starting after sitting; one-cylinder miss under load

Compare with the other causes of the same sign on this engine: hard start, long crank or no-start (3 causes) · oil leak, oil consumption or rising oil level · misfire, rough idle, hesitation or surging (3 causes)

Root cause

Piezo injectors fail electrically and mechanically (nozzle wear, internal leakage) with mileage and fuel quality; contamination events from the CP4 cascade destroy injectors in bulk. Individual replacement economics push owners toward full-set decisions.

Diagnosis

read injector balance rates per cylinder with a scan tool before ordering
a return-flow/balance test separates electrical from mechanical injector faults

Fixes

replace failed injectors (high-cost item; verify per-card revision windows inside 2011-2016) ()

injector - more than one option: Duramax LML Fuel Injector Kit 2011-2016 (OEM), Duramax LGH Injector Kit, van (19210900), Duramax LML Fuel Injector Assembly, Reman Kit (OEM)

Prevalence

occasional