The Mercedes-Benz M 102.983 is a 2,716 cc, inline-six petrol engine produced between 1984 and 1993. It features a single overhead camshaft (SOHC), 12-valve configuration, and Bosch KE-Jetronic continuous fuel injection, delivering 115 kW (156 PS) at 5,500 rpm and 230 Nm of torque at 4,000 rpm. The M 102 series was engineered for smooth refinement and durability in mid-size and luxury applications.
Fitted to models such as the W124 280 E and W201 280 E, the M 102.983 was designed for balanced performance and relaxed cruising. Emissions compliance was achieved through catalytic converters and oxygen sensor feedback control, allowing Euro 1 compliance across its production run in European markets.
One documented concern is premature camshaft wear, particularly in engines subjected to extended oil change intervals. This issue, referenced in Mercedes-Benz Service Information Bulletin 02-85-01, is attributed to inadequate lubrication under high-load operation. In 1987, revised camshaft materials and updated oil pump calibration were introduced to improve longevity.
Production years 1984–1993 meet Euro 1 standards (VCA UK Type Approval #VCA/EMS/2470).
The Mercedes-Benz M 102.983 is a 2,716 cc inline-six petrol engine engineered for mid-size and luxury sedans (1984–1993). It combines Bosch KE-Jetronic continuous fuel injection with a SOHC valvetrain to deliver smooth power delivery and long-term durability. Designed to meet early catalytic converter regulations, it balances drivability with reliability in pre-OBD automotive applications.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,716 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-6, SOHC, 12-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 87.0 mm × 75.6 mm | |
| Power output | 115 kW (156 PS) @ 5,500 rpm | |
| Torque | 230 Nm @ 4,000 rpm | |
| Fuel system | Bosch KE-Jetronic continuous fuel injection | |
| Emissions standard | Euro 1 | |
| Compression ratio | 9.0:1 | |
| Cooling system | Water-cooled | |
| Timing system | Single-row timing chain | |
| Oil type | SAE 10W-40 (API SF/CC) | |
| Dry weight | 185 kg |
The naturally aspirated design provides linear throttle response ideal for relaxed driving, but requires strict adherence to 10,000 km oil change intervals using SAE 10W-40 API SF/CC oil to prevent camshaft lobe wear. The Bosch KE-Jetronic system is sensitive to vacuum leaks and fuel pressure inconsistencies, so regular inspection of hoses and warm-up regulator function is essential. From 1987, updated camshaft metallurgy and oil pump calibration reduced wear incidence. Engines with extended oil service intervals show elevated cam wear rates (Mercedes-Benz SIB 02-85-01). Catalytic converter-equipped models require unleaded fuel only to prevent catalyst poisoning. Air injection systems must remain intact to maintain emissions compliance and prevent oxygen sensor fouling.
Oil Specs: Requires SAE 10W-40 API SF/CC specification (Mercedes-Benz Service Sheet 11.02.85). Modern equivalents must meet backward compatibility.
Emissions: Euro 1 certification applies to all models (1984–1993) (VCA Type Approval #VCA/EMS/2470).
Power Ratings: Measured under DIN 70020 standards. Output consistent across all markets with 98 RON fuel.
Mercedes-Benz Technical Information System (TIS): Docs 640.0010, M102.983
VCA Type Approval Database (VCA/EMS/2470)
Bosch Automotive Fuel Injection Handbook
The Mercedes-Benz M 102.983 was used across Mercedes-Benz's W124/W201 platforms with longitudinal mounting and rear-wheel drive layout. This engine received platform-specific adaptations-shorter intake manifolds in the W201 and revised exhaust manifolds in the W124-and from 1987 the facelifted W124 models adopted an updated camshaft design per SIB 02-85-01, creating partial interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left-side cylinder block near the transmission bellhousing (Mercedes-Benz TIS 640.0010). The 6th and 7th digits of the VIN indicate engine type ('12' for M102-series). Pre-1987 engines have ribbed valve covers with chrome trim; post-1987 units use smooth black valve covers. Critical differentiation from M102.920: M 102.983 uses Bosch KE-Jetronic injection with fuel distributor and warm-up regulator, while M102.920 uses carburetion. Service parts require production date verification—camshafts before 04/1987 are not compatible with later models due to material redesign (Mercedes-Benz SIB 02-85-01).
The M 102.983's primary reliability risk is camshaft lobe wear, with elevated incidence in vehicles with extended oil change intervals. Internal Mercedes-Benz quality reports from 1988 indicated over 10% of pre-1987 units required camshaft replacement before 120,000 km, while UK VCA emissions test data links a significant share of hydrocarbon failures to worn cam profiles in high-mileage vehicles. Infrequent oil changes and use of non-specification oil increase wear rates, making maintenance adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (1984-1993) and UK VCA failure statistics (1985-1995). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M102983.
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Regulation (EC) No 715/2007
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