The Mercedes OM628 engine is an 8-cylinder diesel engine in a V-configuration with direct injection and turbocharger, developed and produced by Daimler-Benz for use in Mercedes-Benz mid-range passenger cars. OM 628 debuted in the summer of 2000 in the Mercedes S 400 CDI S-Class (220 series).
Also used in the E-Class (W 211) and in the G-Class and M-Class SUVs (W 163). The OM628 engine was Daimler-Chrysler’s answer to the rival’s Audi A8 and BMW 740d with their 8-cylinder diesels. The engine block and cylinder heads are made of aluminum alloy by sand casting.
Mercedes diesel V8 family: OM628, OM629.
Specifications
| Production years | 1999-2005 |
| Displacement, cc | 3996 |
| Fuel system | Common Rail |
| Power output, hp | 250 – 260 |
| Torque output, Nm | 560 |
| Cylinder block | aluminum V8 |
| Block head | aluminum 32v |
| Cylinder bore, mm | 86 |
| Piston stroke, mm | 86 |
| Compression ratio | 18.5 |
| Features | intercooler |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | no |
| Turbocharging | GT1749V |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 10.5 |
| Fuel type | diesel |
| Euro standards | EURO 4 |
| Fuel consumption, L/100 km (for Mercedes ML 400 CDI 2003) — city — highway — combined |
14.7 8.8 10.9 |
| Engine lifespan, km | ~300 000 |
| Weight, kg | 275 |
The engine was installed on:
- Mercedes E-Class W211 in 2002 – 2005;
- Mercedes G-Class W463 in 2001 – 2005;
- Mercedes ML-Class W163 in 2001 – 2005;
- Mercedes S-Class W220 in 1999 – 2005.
Disadvantages of the OM628 engine
The OM628 engine is famous for its many problems and the difficulty in fixing them:
- the main troubles are caused by constantly pouring injectors, as well as fuel injection pump failures;
- the motor tends to coke very quickly, especially the EGR;
- prolonged overheating can lead to scuffing in the cylinder liners;
- on runs of 150+ thousand km, many owners have encountered cylinder head cracks.
Frequently asked questions about the Mercedes OM628
How much power does the Mercedes OM628 make?
The Mercedes OM628 develops 250 - 260 hp and 560 Nm of torque.
How much oil does the Mercedes OM628 take and which one?
Engine oil capacity: 10.5 liters. Recommended oil: 5W-30.
Does the Mercedes OM628 have a timing belt or chain?
The Mercedes OM628 uses a timing chain.
Is the Mercedes OM628 turbocharged?
Yes, the Mercedes OM628 is turbocharged (GT1749V).
Does the Mercedes OM628 need valve clearance adjustment?
No, the Mercedes OM628 has hydraulic lifters, so the valve clearances do not need to be adjusted.
How long does the Mercedes OM628 last?
The typical lifespan of the Mercedes OM628 is ~300 000 km with proper maintenance.
What is the fuel consumption of the Mercedes OM628?
Mercedes ML 400 CDI 2003: city 14.7, highway 8.8, combined 10.9 L/100 km.
What cars was the Mercedes OM628 installed on?
Mercedes E-Class W211 in 2002 - 2005; Mercedes G-Class W463 in 2001 - 2005; Mercedes ML-Class W163 in 2001 - 2005; Mercedes S-Class W220 in 1999 - 2005.
What are the common problems of the Mercedes OM628?
the main troubles are caused by constantly pouring injectors, as well as fuel injection pump failures. the motor tends to coke very quickly, especially the EGR. All known problems.
What engines are related to the Mercedes OM628?
Mercedes diesel V8 family: OM629.
