C200 / C220 / C250 CDI 2.1 (OM651, 2009+)
2009–2014 · diesel · 2143cc · 170hp
Engine codes: OM607, OM651
Reliability, common problems and owner reviews for the Mercedes Benz C-Class W204 C200 / C220 / C250 CDI 2.1 (OM651, 2009+). Check this before you buy used.
The GLA diesels split between the smaller Renault-sourced 1.5 (OM607, the 180d — frugal but modest, K9K-derived) and the Mercedes 2.1 (OM651, 200d/220d — stronger). The OM607 carries the Renault diesel's injector/EGR/DPF cautions; the OM651 carries its known early-Delphi-injector risk and rear-chain wear. Both want clean oil and DPF attention on short trips. A documented, motorway-driven car is dependable; the OM651 220d is the better-matched engine for the crossover.
Same engine, other cars
This is the same physical engine (OM607) sold under different names across brands. Reliability is broadly shared — cross-check these:
Known Issues
Early OM651 piezo injectors fail; later cars use solenoid injectors (identifiable by fuel return lines). Verify on the specific car.
Fix / Workaround: Confirm injectors were replaced; budget if not (expensive).
Repair cost: €600–€2000
Typically appears after: 120,000 km
Some reports of timing-chain issues.
Fix / Workaround: Listen for rattle; inspect.
Repair cost: €600–€1500
Typically appears after: 150,000 km
Water pump issues; EGR/DPF on short trips.
Fix / Workaround: Replace pump; motorway runs for DPF.
Repair cost: €200–€1000
Early OM651 Delphi injectors can fail; rear-mounted chain can rattle (labour-heavy).
Fix / Workaround: Injector test; chain rattle check; revised parts.
Repair cost: €250–€1600
Typically appears after: 130,000 km
Renault-sourced OM607 has the usual injector/EGR/DPF cautions on short trips.
Fix / Workaround: Motorway regens; injector/EGR service.
Repair cost: €200–€1000
Typically appears after: 130,000 km
Year Cutoffs
Mileage Thresholds
After 150,000 km: Injector / chain attention possible.
Pre-Purchase Checklist
- ☐Establish injector type/history (piezo vs solenoid)
- ☐Listen for timing-chain rattle
- ☐Best for long/regular journeys
- ☐Check water pump / DPF history
- ☐OM651 220d: injector + chain history
- ☐OM607 is the smaller Renault-derived 1.5
- ☐DPF history (city cars)
Frequently asked questions
Is the Mercedes Benz C-Class W204 C200 / C220 / C250 CDI 2.1 (OM651, 2009+) reliable?
History-Dependent — The GLA diesels split between the smaller Renault-sourced 1.5 (OM607, the 180d — frugal but modest, K9K-derived) and the Mercedes 2.1 (OM651, 200d/220d — stronger). The OM607 carries the Renault diesel's injector/EGR/DPF cautions; the OM651 carries its known early-Delphi-injector risk and rear-chain wear. Both want clean oil and DPF attention on short trips. A documented, motorway-driven car is dependable; the OM651 220d is the better-matched engine for the crossover.
What are the common problems and reviews for the Mercedes Benz C-Class W204 C200 / C220 / C250 CDI 2.1 (OM651, 2009+)?
The most commonly reported problems: Piezo injector failure (early cars), Timing chain wear, Water pump / emissions, OM651 injector (early Delphi) / chain, DPF / EGR / injectors (OM607).
Is a used Mercedes Benz C-Class W204 C200 / C220 / C250 CDI 2.1 (OM651, 2009+) worth buying?
The engine itself is OK; condition is everything. Unknown or patchy history = walk away.