668.940 engine — Mercedes-Benz 1.7 CDI (1.7L)
1.7L · 75-90 hp
Engine overview
Vehicles with this engine
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
| Engine code | 668.940 |
| Capacity | 1689 cc |
| Idle speed | 650 - 850 rpm |
| Normal | 28.0 bar |
| Minimum | 18.0 bar |
| Differential limit between cylinders | 3.0 bar |
| Oil pressure | > 0.7 / 760 > 1.2 / 1200 > 2.8 / 2800 > 3.0 / 4400 bar/rpm |
Engine (diesel)
| System (make and type) | Bosch EDC 15C0 |
| Number of cylinders | 4 |
| Injector firing order | 1 - 3 - 4 - 2 |
| Injector (make and type) | Bosch |
| High-pressure pump: | Bosch |
| Pressure | ± 90 bar |
| Low-pressure pump: | Bosch |
| Turbocharger (make and type) | KKK K03 |
| Coolant temperature during test | 70 °C |
| Idle speed, minimum | 650 rpm |
| Idle speed, maximum | 850 rpm |
| Max. no-load governed speed | 4100 - 4400 rpm |
| Exhaust gas analysis | < 1.9 m-1 |
| Test time | 1 s |
| Exhaust gas analysis test method (Germany only) | B |
| Min. no-load governed speed | 4100 rpm |
| Max. no-load governed speed | 4400 rpm |
| Exhaust gas analysis >500 m above sea level | < 1.8 m-1 |
Cooling system
| Cap pressure | 1.4 bar |
| Thermostat opens at | 87 - 102 °C |
Electrical
| Battery | 45 Ah |
| Alternator | 150 A |
Capacities
| Engine sump, incl. filter | 4.5 l |
| Manual transmission | 716.500, 716.502 |
| Gearbox refill | 1.8 l |
| Automatic transmission | 722.701 |
| Gearbox refill | 3.3 l |
| Gearbox refill after overhaul | 6.3 l |
| Cooling system | 6.5 l |
| Air-conditioner refrigerant | 600 g |
| Air-conditioner compressor oil | 100 ml |
Torque settings
| Cylinder head bolts — Stage 1 | 60 Nm |
| Cylinder head bolts — Stage 2 | 90 ° |
| Cylinder head bolts — Stage 3 | 90 ° |
| Cylinder head bolts — Stage 1 | 20 Nm |
| Big-end bearing cap — Stage 1 | 5 Nm |
| Big-end bearing cap — Stage 2 | 15 Nm |
| Big-end bearing cap — Stage 3 | 90 ° |
| Main bearing cap — Stage 1 | 40 Nm |
| Main bearing cap — Stage 2 | 90 ° |
| Glow plugs | 15 Nm |
| Oil plug | 30 Nm |
| Oil filter | 25 Nm |
| Manual transmission drain plug | 30 Nm |
| Wheel nuts | 110 Nm |
| Rear hub | 170 Nm |
Emissions
| Emission code | 70/220*1999/102A |
| Emission standard | Euro 3 |
| CO2 average | 119 - 127 g/km |
| CO | 0.158 g/km |
| NOx | 0.346 g/km |
| HC NOx | 0.368 g/km |
| Particles | 0.039 g/km |
| CO2 average | 146 - 154 g/km |
| CO | 0.132 g/km |
| NOx | 0.454 g/km |
| HC NOx | 0.477 g/km |
Workshop procedures for this engine
Step-by-step procedures from the workshop database.
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Get free diagnosis →Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
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The story behind TorqFix →Workshop data on this page last updated 22 Aug 2026.