Reliability Summary

Engine OM651 (early) — 66/100 CAUTION
Known Issues 4

Engine in this model

Known Issues Across All Engines

Issue Engine Severity Onset
Timing chain stretch and tensioner wear (rear-mounted chain) OM651 (early) critical 150,000 km
DPF + EGR fouling (city use) OM651 (early) high 60,000 km – 120,000 km
Piezo injector failure — 220 CDI (to 2010/11) and 250 CDI OM651 (early) high 50,000 km
Water pump leak (March-July 2009 build) and cylinder-head coolant stub OM651 (early) moderate —