103.987 engine — Mercedes-Benz 3.0 (3L)
3L · 170 hp
Engine overview
Vehicles with this engine
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
| Engine code | 103.987 |
| Capacity | 2960 cc |
| Normal | 12.0 bar |
| Minimum | 7.5 bar |
| Differential limit between cylinders | < 1.5 bar |
| Oil pressure | 0.7 / 600 0.9 / 750 2.0 / 1000 4.3 / 2000 4.6 / 3000 4.8 / 4000 5.0 / 5000 bar/rpm |
Engine (petrol)
| Number of cylinders | 6 |
| Firing order | 1-5-3-6-2-4 |
| Timing stroboscopic (before TDC) | 26 - 30 / 3200 °/rpm |
| Timing stroboscopic (vacuum hose connected) | 46 - 50 / 3200 °/rpm |
| Timing stroboscopic (before TDC) | 21 - 25 / 3200 °/rpm |
| Spark plug gap | 0.8 mm |
| Injection pressure/system pressure | 3.7 - 4.2 bar |
Cooling system
| Cap pressure | 120: 1.2 +/- 0.1 140: 1.4 +/- 0.1 bar |
| Thermostat opens at | 87 +/- 2 °C |
Capacities
| Engine sump, incl. filter | 6.5 l |
| Manual transmission | 717.439 |
| Gearbox refill | 1.5 l |
| Automatic transmission | 722.397 |
| Initial filling | 7.3 l |
| Gearbox refill | 6.2 l |
| Transfer box | 2.8 l |
| Cooling system | 9.0 l |
| Differential, 4WD front | 1.4 l |
| Differential, 4WD rear | 1.8 l |
| Air-conditioner refrigerant | 1000 g |
| Air-conditioner compressor oil | 120 ml |
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 |
| Main bearing cap — Stage 1 | 55 Nm |
| Main bearing cap — Stage 2 | 90 ° |
| Oil plug | 25 Nm |
| Manual transmission filler plug | 60 Nm |
| Manual transmission drain plug | 60 Nm |
| Automatic transmission drain plug | 14 Nm |
| Wheel bolts | 180 Nm |
| Wheel bolts | 130 Nm |
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.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
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The story behind TorqFix →Workshop data on this page last updated 22 Aug 2026.