103.981 engine — Mercedes-Benz 3.0 (3L)
3L · 188 hp
Engine overview
Vehicles with this engine
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
| Engine code | 103.981 |
| Capacity | 2962 cc |
| Idle speed | 600 - 700 rpm |
| Normal | 12.0 bar |
| Minimum | 8.5 bar |
| Oil pressure | 0.9 / 750 2.0 / 1000 4.3 / 2000 4.6 / 3000 4.8 / 4000 5.0 / 5000 bar/rpm |
Engine (petrol)
| Fuel system (make and type) | Bosch KE-Jetronic |
| Number of cylinders | 6 |
| Firing order | 1-5-3-6-2-4 |
| Timing stroboscopic (before TDC) | 27 - 31 / 3200 °/rpm |
| Timing stroboscopic (vacuum hose connected) | 40 - 44 / 3200 °/rpm |
| Timing stroboscopic (before TDC) | 21 - 25 / 3200 °/rpm |
| Ignition coil resistance, primary | 0.3 - 0.6 ohms |
| Ignition coil resistance, secondary | 8000 - 13000 ohms |
| Spark plugs (make and type) | Beru 14 K-8 DU Beru 14 K-8 DUO Bosch H 8 DC Bosch H 8 DCO Champion S 10 YC Champion S 10 YCC |
| Spark plug gap | 0.8 mm |
| Injection pressure/system pressure | 5.3 - 5.5 bar |
| CO exhaust gas | 0.5 - 1.5 % |
| 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 change (Delta Lambda) | 0.02 |
| Lambda | 0.97 - 1.03 |
| Oil temperature during test | 60 °C |
| Closed-loop test at: | 500 - 1100 rpm |
Cooling system
| Cap pressure | 120: 1.2 ± 0.1 140: 1.4 ± 0.1 bar |
| Thermostat opens at | 87 ± 2 °C |
Electrical
| Battery | 66 Ah |
| Alternator | 80 A |
Capacities
| Engine sump, incl. filter | 6.0 l |
| Gearbox refill | 1.5 l |
| Differential | 1.0 l |
| Automatic transmission | 722.351 |
| Gearbox refill | 6.2 l |
| Gearbox refill after overhaul | 7.3 l |
| Cooling system | 8.0 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 |
| Wheel nuts | 110 Nm |
| Rear hub | 30 Nm |
| Rear hub | 90 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.