OM651DE22LA Diesel Injectors
Common-rail diesel injectors with full UK warranty
- OEM Tested & Calibrated
- 12-Month Warranty
- Free UK Delivery
Select the correct injector for your OM651DE22LA engine below
Top injectors for OM651DE22LA
Compatible Injectors for OM651DE22LA
- OEM Tested
- 12-Month Warranty
- Free UK Delivery
Common problems solved by these injectors
About the OM651DE22LA engine
The OM651DE22LA (commonly known as OM651) is the full technical designation of the Mercedes-Benz 2.1-litre CDI diesel engine. This engine uses Delphi common rail injectors with primary part number A6510704987. It was fitted across the Mercedes-Benz range from 2008 to 2021 including the C-Class, E-Class, CLA, GLA, Vito, and Sprinter.
How Diesel Injectors Are Remanufactured
Watch our 3D walkthrough of the diesel injector remanufacturing process and see how injectors are professionally restored for reliable service.
Vehicles Using OM651DE22LA Engine
Vehicle data not yet available for this engine code.
Common OM651DE22LA Injector Problems
Rough idle and engine vibration
Worn injector nozzles cause uneven fuel spray, leading to rough idle at low RPM. Most noticeable when the engine is cold.
Excessive exhaust smoke
Black or blue-grey smoke on acceleration indicates poor fuel atomisation. This is often caused by carbon buildup on the injector nozzle tip.
Poor fuel economy
A worn or leaking injector delivers incorrect fuel quantities, reducing efficiency by 10–20% in severe cases.
Engine misfire under load
Intermittent misfires during acceleration suggest one or more injectors are failing to deliver the correct fuel pressure.
Difficult cold starting
Degraded injector nozzles struggle to atomise fuel at lower cranking pressures, causing extended crank times in cold weather.
Loss of power
Gradual power loss across the rev range, particularly above 2500 RPM, can indicate injector flow rate degradation.
Increased diesel knock
Louder than normal combustion noise, especially at idle, can indicate incorrect injection timing due to worn injector internals.
OM651DE22LA Technical Specifications
Displacement
2143 cc
Power
100–150 kW (136–204 PS)
Torque
300–500 Nm
Fuel System
Common Rail Direct Injection
The OM651DE22LA (commonly known as OM651) is the full technical designation of the Mercedes-Benz 2.1-litre CDI diesel engine. This engine uses Delphi common rail injectors with primary part number A6510704987. It was fitted across the Mercedes-Benz range from 2008 to 2021 including the C-Class, E-Class, CLA, GLA, Vito, and Sprinter.
Engine Intelligence
Mercedes 2.1 CDI (OM651 Delphi era — C-Class, E-Class, Sprinter, Vito)
Documented failure modes
- Early Delphi piezo injector failures — widely documented on 2009–2011 OM651 engines, addressed by a manufacturer service campaign
- Injector delivery drift with correction values out of range
- Injector leakage allowing fuel dilution of the engine oil in advanced cases
Diagnostic guidance
- Check injector correction values across all four cylinders — an outlier identifies the failing unit
- On early (2009–2011) engines with running complaints, injector history matters: many were replaced under the manufacturer campaign — verify which units are fitted
- Monitor the engine-oil level on suspected leaking injectors
- Injector coding is required after fitting — follow the manufacturer procedure
Fitment note: OM651 injection changed technology over its life — early Delphi piezo units differ from the later Bosch solenoid type (OM651950-era); the two are NOT interchangeable and this guidance covers the Delphi era only. Always match the reference etched on the injector body.
Related OM651DE22LA Engine Guides
Related Pages
Delphi 2.1L CDI — browse compatible engines, vehicles, and injectors
Compatible Engines
Compatible Vehicles
Recommended Injector
A6510704987
Delphi — View product page