2018 GMC Sierra Service and Repair Manual
This factory service and repair manual for the 2018 GMC Sierra closes out this generation of the truck with the flex-fuel 325-cubic-inch 5.3L V8 and the gasoline 376-cubic-inch 6.2L V8, both naturally aspirated overhead-valve engines. Crew cab and standard cab pickups are covered, in All Terrain, Denali and SLE trim. The work the book does is unglamorous and specific: component procedures, specifications, torque values, wiring diagrams and diagnostics, arranged by system rather than by model designation.
Engines covered
- 5.3L V8 (325 cu in) — OHV, naturally aspirated, flex-fuel
- 6.2L V8 (376 cu in) — OHV, naturally aspirated, gasoline
Body styles covered
- 4-door crew cab pickup
- 2-door standard cab pickup
Trims covered
- All Terrain
- Denali
- SLE
Known issues on the 2018 Sierra. Of the seven recalls logged federally, four describe the same failure in the roof-rail air bags, where an inflator end cap can detach or the inflator sidewall can rupture, letting compressed gas escape and throwing pieces into the cabin. Two more concern the mechanical vacuum pump losing output, which raises brake pedal effort and stretches stopping distance. A wheel speed sensor fault could also brake one wheel on its own. Complaints total 298, led by the power train at 116, the engine at 34 and the electrical system at 31.
