Failure mode - Mercedes-Benz 2.1L Twin-Turbo Diesel (Sprinter 2014-2018)

EGR system: coking and cooler coolant leak

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

Symptoms

white smoke on cold start, unexplained coolant loss
EGR flow DTCs, loss of power
coolant film in the intake piping (cooler leaking into the intake path)

Compare with the other causes of the same sign on this engine: loss of power, limp mode or derate (4 causes) · white smoke from the exhaust · losing coolant

Root cause

Two OM651 EGR modes: ordinary coking (EGR soot feeds the swirl-flap jams) and the cooler leak - the EGR cooler bypass/shutoff valve sticks or the cooler passes coolant into the intake. The coolant-into-intake mode is the Sprinter-relevant one: owners trace white smoke and coolant loss to the cooler.

Diagnosis

pressure-test the cooling system and inspect the intake path for coolant film
command the EGR cooler bypass valve; check for boost leaks around it
inspect the valve pintle for coking; clean vs replace per findings

Fixes

EGR cleaning / valve replacement / cooler replacement per diagnosis ()

egr-valve - more than one option: OM651 EGR Valve (651-140-08-60, current), OM651 EGR Valve Gasket (651-142-23-80)
OM651 EGR Cooler (651-140-07-00, current)

Prevalence

common