Recipe - GM 6.0L V8 Gasoline (GM HD, LY6-L96 2008-2019; Express/Savana vans 2008-2020)
Reliability build
Reliability tier: verified - verify before ordering, see /disclosure/
Ignition service for the HD 6.0 gas (mode Ignition misfire: coils and spark plugs (L96/LY6)): 16 plugs on the OHV V8, one coil per cylinder. Plugs split at the 2015 body boundary (19417055 early / 12680072 late); coils are one current PN (12739916). Swap-test a suspect coil before buying.
Parts
- GM 6.0L HD Spark Plug 2008-2014 (OEM) - spark plug, 2008-2014 window (19417055) (qty 16)
- GM 6.0L HD Spark Plug 2015-2019 (OEM) - spark plug, 2015-2019 window (12680072) (qty 16)
- GM 6.0L HD Ignition Coil (OEM) - ignition coil, current PN, swap-test suspects (12739916) (qty 1)
Install order
- read misfire counters per cylinder; map steady vs random misses
- swap-test the suspect coil to a good cylinder - the miss follows a bad coil
- renew all 16 plugs with the year-correct PN (2015 body boundary); dielectric on the boots
Expected outcome
Clean idle, no misfire counters, no flashing MIL.
Do not
- do not mix the 2008-2014 and 2015-2019 plug PNs across the body boundary
Parts budget
About $85-$240 in parts. It depends on what the diagnosis finds; each option below is what you buy together. Prices marked "at Dave's" are Dave's Auto Center's, the same as in his store; the others are approximate prices from OEM and maker catalogs, rounded (a manufacturer's list price can run higher). Parts only, no labor.