2007 Chevrolet Chevrolet Silverado 2500 HD

Reliability tier: verified - see /disclosure/

Engine: 6.0L V8 Gasoline (Vortec 6000, LQ4) (GM Vortec small block, 6.0L), 2v

Vortec 6000 LQ4 (VIN U): GM Gen III LS-family small-block V8, 6.0L (364 cid), OHV 2-valve, cast-iron block / aluminum heads, 9.4:1 compression (the 10:1 LQ9 HO sibling powered the SS/Escalade/Denali lines, not these HD pickups), sequential multiport fuel injection; 300 hp / 360 lb-ft (2001-2002) rising to ~335 hp / 375 lb-ft with the mid-decade updates. 4L80E/4L85E behind it (Allison optional - context only). The standard HD gas engine. Final year of the classic GMT800 HD body; the Gen IV LY6 6.0L arrived with the 2007 new body, not here.

Applicable failure modes (3)

Exhaust manifold bolt breakage (cold-start tick)
Hard cold start / fuel delivery wear
Ignition service at mileage: coils, wires, plugs (misfire under load)

Applicable parts (14)

6.0L Vortec Spark Plug / Coil Wire (OEM)
gm-hd-gas-vortec: exhaust-manifold-bolt (honest catalog gap)
gm-hd-gas-vortec: exhaust-manifold (honest catalog gap)
6.0L Vortec Fan Clutch (OEM)
6.0L Vortec Fuel Injector (OEM)
GM HD In-Tank Fuel Pump Module 2004-2007 (OEM)
6.0L Vortec Fuel Rail, Passenger Side (OEM)
6.0L Vortec Fuel Rail Assembly 2004-2007 (OEM)
6.0L Vortec Cylinder Head Gasket Kit (OEM)
6.0L Vortec Ignition Coil Kit (OEM)
GM Truck V8 Ignition Coil (shared 4.8-8.1 line) (OEM)
6.0L Vortec Spark Plug (OEM)
6.0L Vortec Spark Plug Wire Kit (OEM)
6.0L Vortec Thermostat (OEM)

Platform recipes (3)

Cold-start tick on a 6.0L or 8.1L GMT800 HD gas truck: find the leaking manifold flange before blaming lifters or injectors, then extract the sheared studs and refit bolts and gaskets (mode fm-gvg-exhaust-manifold-bolts)
Hard-cold-start path (fm-gvg-fuel-delivery-cold-start): the owner record puts most cases on tired in-tank pumps and rail pressure bleed-down, not ignition
Ignition service path (fm-gvg-ignition-misfire): misfire under load / rough idle at mileage on the 2001-2007 HD gas engines