OM6563.0L Diesel
The OM656 is Mercedes-Benz's all-aluminium 3.0L inline-6 diesel introduced in 2017, replacing the OM642 V6 and returning Mercedes diesels to the inline-6 format after two decades. Shares bore spacing and modular architecture with the OM654 4-cylinder. Twin sequential turbocharging on higher-output variants delivers up to 367 hp and 750 Nm. Uses NANOSLIDE bore coating and stepped-recess pistons. Emissions-hardware reliability (AdBlue, NOx sensors, DPF) dominates the fault list rather than mechanical issues.
9
Fits chassis
2017–null
Years built
367 hp
Power
Used to fully refurbished — quoted per unit
3-month parts warranty
Cover on every used part we dispatch.
Nationwide courier
Courier Guy & Aramex — door to door.
Fitment guaranteed
Send your VIN — we confirm before you pay.
Bench-tested
Inspected and tested before dispatch.
OM656 at a glance
| Displacement | 3.0L |
| Fuel type | Diesel |
| Power variants | 286 hp, 313 hp, 330 hp, 340 hp, 367 hp |
| Years produced | 2017–null |
| Replaces | OM642 |
| Replaced by | — |
OM656 fits these 9 Mercedes chassis
Each card links to that chassis hub — full parts catalogue plus fitment notes.
- W2132017-2023E-ClassE350d/E400dView parts
- W2142023-2025E-ClassE450d
- W2222017-2020S-ClassS350d/S400dView parts
- W2232020-2025S-ClassS400d/S450d
- W1672019-2025GLE-ClassGLE400d/GLE450dView parts
- C1672020-2025GLE CoupeGLE400d
- X1672019-2025GLS-ClassGLS400dView parts
- C2572018-2023CLS-ClassCLS400d
- W4632019-2025G-ClassG350d/G400d
Common OM656 problems
We disclose every known fault before sale. Transparency is cheaper than a bad return.
- AdBlue (DEF) injector and pump failures causing limp mode warnings
- EGR cooler internal coolant leaks (less prevalent than OM642 but still seen at high mileage)
- Diesel particulate filter (DPF) clogging on short-trip and urban use
- Twin-turbo electric actuator failures on 400d/450d variants
- 48V starter-generator integration faults on EQ Boost variants
- NOx sensor failures triggering AdBlue countdown warnings
Featured parts for the OM656
No live OM656 listings right now
We strip 10–15 cars a month. Send your VIN and we'll WhatsApp you the moment one comes in.
OM656 rebuilds — what to budget
Bench-tested used long blocks start around R 75 000 delivered, full forensic rebuilds with new wear items run up to R 130 000. Final price depends on mileage, ancillaries (turbo, injectors, flywheel) and warranty tier — quoted per unit, no list-price surprises.
Send us your VIN — we'll match the right unit
We confirm engine number, ancillaries and warranty tier in writing before you pay.
Tell us about your Mercedes — we'll source the OM656
Three short steps. We reply within 2 hours during business hours with engine number, mileage, condition and a delivered price.
- Engine number confirmed against your VIN
- Bench-tested before dispatch
- 3-month warranty + nationwide courier
OM656 engine — common questions
Door-to-door courier from R 199
All major SA cities · 1–3 working days · Insured shipping on every order · Couriered from Centurion