103.940 engine — Mercedes-Benz 2.6 (2.6L)
2.6L · 166 hp
Engine overview
Vehicles with this engine
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
| Engine code | 103.940 |
| Capacity | 2599 cc |
| Idle speed | 600 - 800 rpm |
| Normal | 9 - 12 bar |
| Minimum | 7.5 bar |
| Oil pressure | 3/3000 bar/rpm |
Engine (petrol)
| Fuel system (make and type) | Bosch KE-Jetronic |
| Idle speed adjustment screw | A |
| CO adjustment screw | B |
| Number of cylinders | 6 |
| Firing order | 1-5-3-6-2-4 |
| Timing stroboscopic (before TDC) | 7 - 11 °/rpm |
| Ignition coil resistance, primary | 0.3 - 0.6 ohms |
| Ignition coil resistance, secondary | 8000 - 13000 ohms |
| Spark plugs (make and type) | Beru 14K8DUO Bosch H8DCO |
| Spark plug gap | 0.8 mm |
| CO exhaust gas | 1.0 ± 0.5 % |
| Catalytic converter | < 0.5 % |
| CO2 | 13.0 - 16.0 % |
| Catalytic converter | 14.5 - 16.0 % |
| HC | 300 ppm |
| Catalytic converter | 100 |
| O2 | 0.5 - 2.0 % |
| Catalytic converter | 0.1 - 0.5 % |
| CO at fast-idle speed | 0.3 % |
| Fast-idle speed | 2200-2800 rpm |
| Lambda | 0.97 - 1.03 |
| Lambda change (Delta Lambda) | 0.02 |
| Oil temperature during test | 60 °C |
| Closed-loop test at: | 500-1100 rpm |
| Alternative method (Germany only) | Nr. G2 |
| Alternative method (Germany only) | Nr. 1b, ± 10 |
Cooling system
| Cap pressure | 1.3 - 1.5 bar |
| Thermostat opens at | 85 - 89 °C |
Electrical
| Battery | 55 Ah |
| Alternator | 70 A |
Capacities
| Engine sump, incl. filter | 5.0 l |
| Gearbox refill | 1.5 l |
| Differential | 1.1 l |
| Gearbox refill | 6.0 l |
| Differential | 0.7 l |
| Cooling system | 9.0 l |
| Cooling system | 9.5 l |
Torque settings
| Cylinder head bolts — Stage 1 | 70 Nm |
| Cylinder head bolts — Stage 2 | 90 ° |
| Cylinder head bolts — Stage 3 | 90 ° |
| Spark plugs | 20 Nm |
| Front hub | 12 Nm |
| Rear hub | 200-240 Nm |
| Wheel nuts | 110 Nm |
Workshop procedures for this engine
Step-by-step procedures from the workshop database.
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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.