OM651 Diesel Injectors
Compatible with Mercedes-Benz C-Class, Mercedes-Benz CLA, Mercedes-Benz E-Class, and 6 more
- OEM Tested & Calibrated
- 12-Month Warranty
- Free UK Delivery
Select the correct injector for your OM651 engine below
Fits Mercedes-Benz C-Class, Mercedes-Benz CLA, Mercedes-Benz E-Class, Mercedes-Benz GLA and more
Top injectors for OM651
Compatible Injectors for OM651
- OEM Tested
- 12-Month Warranty
- Free UK Delivery
Common problems solved by these injectors
About the OM651 engine
The OM651 is a 2.1-litre inline-4 turbodiesel engine produced by Mercedes-Benz. Known internally as the OM651DE22LA, this engine was one of the most widely used diesel powertrains across the Mercedes-Benz lineup from 2008 to 2021. It uses Delphi common rail diesel injectors (primary OEM number A6510704987) operating at fuel pressures up to 2000 bar. The OM651 powered vehicles from the C-Class (…
Vehicles Using OM651 Engine
| Vehicle | Engine | Years |
|---|---|---|
| Mercedes-Benz C-Class injector | 2.1 CDI | 2008–2018 |
| Mercedes-Benz CLA injector | 2.1 CDI | 2013–2018 |
| Mercedes-Benz E-Class injector | 2.1 CDI | 2009–2016 |
| Mercedes-Benz GLA injector | 2.1 CDI | 2014–2019 |
| Mercedes-Benz GLK injector | 2.1 CDI | 2012–2015 |
| Mercedes-Benz SLK injector | 2.1 CDI | 2012–2016 |
| Mercedes-Benz Sprinter injector | 2.1 CDI | 2014–2018 |
| Mercedes-Benz V-Class injector | 2.1 CDI | 2014–2019 |
Common OM651 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.
OM651 Technical Specifications
Displacement
2143 cc
Power
100–150 kW (136–204 PS)
Torque
300–500 Nm
Fuel System
Common Rail Direct Injection
The OM651 is a 2.1-litre inline-4 turbodiesel engine produced by Mercedes-Benz. Known internally as the OM651DE22LA, this engine was one of the most widely used diesel powertrains across the Mercedes-Benz lineup from 2008 to 2021. It uses Delphi common rail diesel injectors (primary OEM number A6510704987) operating at fuel pressures up to 2000 bar. The OM651 powered vehicles from the C-Class (W204/W205), E-Class (W212), CLA, GLA, GLK, Vito, V-Class, Sprinter, and SLK, in various power outputs from 136 PS to 204 PS. Injector failures on the OM651 typically present after 100,000–150,000 miles as rough idle, excessive smoke, and loss of power. Always replace copper sealing washers and torque to Mercedes specifications when fitting replacement injectors.
Engine Intelligence
Fitment note: Always confirm compatibility using registration lookup or part number before ordering.
Related OM651 Engine Guides
Related Engines
Related Pages
Delphi 2.1L CDI — browse compatible engines, vehicles, and injectors
Compatible Engines
Compatible Vehicles
Recommended Injector
A6510704987
Delphi — View product page