Failure mode - Cummins 5.9L Diesel (Dodge Ram HD)

Common-rail injector wear / nozzle carbon (03-07)

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

Symptoms

cold-start rattle and white smoke that clears warm; uneven idle; rising fuel consumption
metal-on-metal tick from a failing injector; copper crush washer blow-by at the sleeve

Compare with the other causes of the same sign on this engine: white smoke from the exhaust (2 causes) · ticking, knocking, rattle or whine (3 causes) · misfire, rough idle, hesitation or surging (2 causes)

Root cause

The common-rail injectors (Bosch, solenoid) wear with mileage and fuel quality: nozzle carbon, worn control valves and copper washer leaks. Tuned trucks and poor filtration accelerate it.

Diagnosis

balance-rate test (bidirectional scan tool or dealer test) pinpoints the weak injector before replacing a set
inspect connector tubes and copper washers for blow-by soot

Fixes

replace the worn injector(s) with new/reman units; new copper washers and connector-tube seals every time ()

injector - more than one option: 5.9L Cummins Common-Rail Injectors, early build (S&S, 2003-2004.5), 5.9L Cummins Common-Rail Injectors, late build (S&S, 2004.5-2007)
cummins-5_9: injector-seal-kit (honest catalog gap)

Prevalence

common

Parts for this repair run about $2,600-$2,800: see them next to the other repairs on this engine in repair costs.