← Misfire / rough running on all engines
Symptoms · GM 6.0 L96 (gas)
GM 6.0 L96 (gas): misfire, rough idle, hesitation or surging
3 documented failures on this engine list this among their signs. They are ordered from the most widespread down. Each one shows the signs in its record's own words, how to tell it from the others, the usual fix and any recall or bulletin.
Not sure which engine you have, or want the recalls for your exact truck? Check your VIN: it names the engine and lists the campaigns for that model year. Whether a recall is still open on your VIN: nhtsa.gov/recalls.
verified
How widespread: Common
How it shows up
- lean misfire under load traced to pressure drop; injector balance complaints
Its other signs
- hard starting after sitting, long cranks; fuel pump whine before outright failure
- flex-fuel (L96) fuel system service themes
How to tell it apart
- log fuel pressure at rail and at the pump; compare hot vs cold
- rule out the sender/module harness before condemning the pump
- injector balance or smoke-test the intake for vacuum leaks first
Usual fix
renew the failed injector/pressure component as testing dictates; the in-tank pump module PN is a catalog gap (disclosed) - parts records carry the injector and rail
Root cause, parts and sources →
verified
How widespread: Common
How it shows up
- rough idle and flashing MIL on a cold start; cylinder-specific misfire codes
Its other signs
- coil-on-plug failures (one per cylinder, 16 plugs on the V8); worn plugs at 100k service intervals
How to tell it apart
- read the specific cylinder misfire counters, then swap the coil to another cylinder to separate coil from plug
- check plug gaps and boots on the failed cylinder before replacing the coil
Usual fix
renew failed coils and/or plugs (full-set plug service at the interval)
Root cause, parts and sources →
aggregated
How widespread: Occasional
How it shows up
- cold-start ticking that fades warm; a cylinder dropping contribution at mileage
Its other signs
- traditional lifter/rocker wear - NOT the AFM lifter-collapse family (the HD 6.0 has no AFM/DFM; the half-ton 5.3/6.2 AFM reputation does not transfer here)
How to tell it apart
- locate the cylinder by stethoscope/tick timing before replacing parts
- check oil pressure and filter condition - oiling drives lifter wear
Usual fix
renew the failed lifter/rocker set; use the correct oil spec on refill - the dealer catalog does not surface HD-gas lifter PNs (catalog gap, disclosed)
Root cause, parts and sources →
Other symptoms on the GM 6.0 L96 (gas)
Ticking, knocking, rattle or whine
Everything on the GM 6.0 L96 (gas)Its recalls and bulletins