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2005 GMC GMC Sierra 3500
Reliability tier: verified - see /disclosure/
Engine: 6.6L Duramax LLY (Duramax, 6.6L)
LLY generation: 310hp @ 3,000 / 605 lb-ft @ 1,600; common-rail Bosch CP3, Allison 1000 behind the diesel (context only). First emissions-focused Duramax: Garrett VGT + EGR valve from this generation.
Applicable failure modes (4)
- EGR cooler clogging / failure (LB7-LMM)
- CP3 pump / fuel system contamination
- Head gasket failures (higher mileage / load)
- VGT turbo vane carbon / actuator wear (LLY+)
Applicable parts (27)
- Duramax LLY CP3 Injection Pump (Reman OEM)
- Duramax CP3 Fuel Injection Pump Seal (OEM)
- duramax-lb7-lmm: dpf (honest catalog gap)
- Duramax LLY EGR Cooler (OEM)
- Duramax LLY EGR Valve (OEM)
- Duramax Exhaust Manifold (OEM)
- Duramax LLY+ Fuel Filter 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 LLY Glow Plug (OEM)
- Duramax LLY Cylinder Head Gasket Kit, Less Head Gaskets (OEM)
- Duramax LB7/LLY Cylinder Head Gasket, Grade-Coded (OEM)
- Duramax 6.6L Head Stud Kit (LB7-LMM 2001-2010)
- Duramax LLY Fuel Injector (OEM)
- Duramax 2001-2010 Lift Pump Upgrade (FASS Titanium Signature C10 100G)
- Duramax Engine Oil Cooler Assembly (OEM)
- Duramax Engine Coolant Thermostat (OEM)
- Duramax Turbo Control Solenoid Valve (OEM)
- Duramax Turbo Coolant Thermostat Assembly (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