← Back
2004 Chevrolet Chevrolet Silverado 3500
Reliability tier: verified - see /disclosure/
Engine: 6.6L Duramax LB7 (Duramax, 6.6L)
LB7 generation: 300hp @ 3,100 / 520 lb-ft @ 1,800; common-rail Bosch CP3, Allison 1000 behind the diesel (context only). Copper-injector era: the LB7's injector service is the generation's defining repair (documented in the Duramax history source). Build-date caveat: LLY replaced LB7 mid-year 2004 - a 2004 truck can be either engine; verify the 8th VIN position before ordering generation-specific parts.
Applicable failure modes (4)
- EGR cooler clogging / failure (LB7-LMM)
- CP3 pump / fuel system contamination
- Head gasket failures (higher mileage / load)
- LB7 injector failures (the defining repair of the generation)
Applicable parts (40)
- Duramax LB7 CP3 Injection Pump (Reman OEM)
- Duramax LLY CP3 Injection Pump (Reman OEM)
- Duramax CP3 Fuel Injection Pump Seal (OEM)
- duramax-lb7-lmm: dpf (honest catalog gap)
- Duramax LB7 EGR Cooler (OEM)
- Duramax LLY EGR Cooler (OEM)
- Duramax LB7 EGR Valve (OEM)
- Duramax LLY EGR Valve (OEM)
- Duramax Exhaust Manifold (OEM)
- Duramax LB7 Performance Sending Unit, Fleece SureFlo (2001-2004, for an aftermarket lift pump)
- Duramax LLY+ Fuel Filter Assembly (OEM)
- Duramax LB7 Fuel Filter Head Assembly (OEM)
- Duramax Fuel Filter Heater (OEM)
- Duramax Fuel Filter Service Kit (OEM)
- Duramax LLY+ Fuel Filter Shell Assembly (OEM)
- Duramax CP3 Fuel Pressure Service Valve (OEM)
- Duramax LLY Common Rail Assembly (OEM)
- Duramax LLY/LBZ/LMM Fuel Tank Module Kit (OEM)
- Duramax LB7 Fuel Tank Sender (OEM)
- Duramax LB7 Glow Plug Control Module (OEM)
- Duramax LB7 Glow Plug (OEM)
- Duramax LLY Glow Plug (OEM)
- Duramax LLY Cylinder Head Gasket Kit, Less Head Gaskets (OEM)
- Duramax LB7 Head Gasket Kit - Solid Seal, w/ Grade-C Head Gasket
- Duramax LB7/LLY Cylinder Head Gasket, Grade-Coded (OEM)
- Duramax 6.6L Head Stud Kit (LB7-LMM 2001-2010)
- Duramax LB7 Fuel Injector Kit 8 pcs (Reman OEM)
- Duramax LLY Fuel Injector (OEM)
- Duramax 2001-2010 Lift Pump Upgrade (FASS Titanium Signature C10 100G)
- Duramax Engine Oil Cooler Assembly (OEM)
- Duramax LB7 In-Tank Lift Pump Upgrade (Fleece PowerFlo, 2001-2004)
- Duramax LB7 Fuel Rail Pressure Sensor (OEM)
- Duramax Engine Coolant Thermostat (OEM)
- Duramax Turbo Control Solenoid Valve (OEM)
- Duramax Turbo Coolant Thermostat Assembly (OEM)
- Duramax LB7 Turbocharger (Reman OEM)
- Duramax LLY Turbocharger (OEM)
- Duramax LLY Turbo Vane Position Sensor (OEM)
- Duramax LB7/LLY Water Pump (OEM)
- Duramax Water-In-Fuel Indicator Sensor (OEM)
Platform recipes (6)
- CP3 and fuel-system contamination service (fm-dmx-fuel-system-health): the Bosch CP3 is fed by the OEM filter setup, and water/debris are the standing threats
- LMM DPF-era service (fm-dmx-dpf-era-service): the LMM (from mid-2007) is the first DPF Duramax
- EGR cooler service (fm-dmx-egr-cooler): the Duramax has carried cooled EGR since the LB7 (catalog-verified 97288793 for 2002-2004) and the coolers clog with carbon and eventually leak - the LLY-era heat reputation makes cooler health the first check on heat complaints
- Head-gasket replacement path (fm-dmx-head-gaskets): stock gaskets age and elevated cylinder pressures finish them
- Repair path for the LB7's defining failure (fm-dmx-lb7-injectors): hard starts, white smoke, fuel dilution on 2001-early-2004 trucks
- VGT turbo service path (fm-dmx-vgt-turbo): boost flutter, slow spool, smoke under load