Failure mode - Duramax 6.6L V8 Turbo Diesel (GM HD, LB7-LMM 2001-2010)

CP3 pump / fuel system contamination

Reliability tier: aggregated - verify before ordering, see /disclosure/

Symptoms

metal-content CP3 wear on higher-mileage engines
contamination events that cascade to injectors

Compare with the other causes of the same sign on this engine: metal in the fuel filter or oil

Root cause

The Bosch CP3 is fed by the OEM filter setup; water and debris are the standing threat across the generations. Owner practice adds contamination-protection hardware; no defect-rate statistics.

Diagnosis

sample/inspect for metal on suspected CP3 wear
verify filter condition and water separator function on every diagnosis

Fixes

service: filters on schedule; on contamination events, treat pump+rails+injectors as one system ()

fuel-filter - more than one option: 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)
lift-pump - more than one option: Duramax 2001-2010 Lift Pump Upgrade (FASS Titanium Signature C10 100G), Duramax LB7 In-Tank Lift Pump Upgrade (Fleece PowerFlo, 2001-2004)
injection-pump - more than one option: Duramax LB7 CP3 Injection Pump (Reman OEM), Duramax LBZ/LMM CP3 Injection Pump (Reman OEM), Duramax LLY CP3 Injection Pump (Reman OEM)
Duramax Water-In-Fuel Indicator Sensor (OEM)
Duramax CP3 Fuel Pressure Service Valve (OEM)

Prevalence

common

Parts for this repair run about $10-$890: see them next to the other repairs on this engine in repair costs.