The OM628 engine is an 8-cylinder diesel internal combustion 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.
Specifications OM 628 DE 40 L
| Displacement | 3996 cc |
| Fuel system | Common Rail |
| Power | 250 – 260 hp |
| Torque output | 560 Nm |
| Cylinder block | V8, aluminum |
| Cylinder head | 32v, aluminum |
| Cylinder bore | 86 mm |
| Piston stroke | 86 mm |
| Compression ratio | 18.5 |
| Engine features | intercooler |
| Hydraulic compensators | yes |
| Timing drive | chain |
| Phase regulator | no |
| Turbocharging | two GT1749V |
| Recommended engine oil | 10.5 liters 5W-30 |
| Fuel type | diesel |
| Euro standards | Euro 4 |
| Engine lifespan | 300 000 km |
Frequent problems
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 quickly, first of all it concerns the USR;
- prolonged overheating can lead to scuffing in the cylinder liners;
- on runs of 150+ thousand km, many owners have encountered cylinder head cracks.
Related