The Mercedes-Benz M104.943 is a 2,799 cc, inline-six naturally aspirated petrol engine produced between 1993 and 1998. It featured a cast-iron block, aluminium head, dual overhead camshafts (DOHC), and sequential multi-point fuel injection (Bosch LH-Jetronic 2.4). Delivering 132 kW (180 PS) and 255 Nm of torque, it was engineered for smooth, refined power delivery in executive sedans and coupes.
Fitted to key models including the W124 280E, W210 E280, and C208 CLK280, the M104.943 was designed to balance performance and refinement for premium touring applications. Its driving character emphasized linear throttle response and strong mid-range pull, making it well-suited for sustained highway cruising. Emissions compliance was achieved through oxygen-sensor feedback control and a three-way catalytic converter, meeting Euro 2 standards.
One documented concern is premature camshaft wear, particularly in engines subjected to extended oil change intervals or improper lubrication. This issue, referenced in Mercedes-Benz Service Information Bulletin 07 05 89, is attributed to inadequate oil flow to the camshaft journals under certain operating conditions. In response, revised oil pump designs and updated maintenance intervals were introduced in 1993 to improve lubrication reliability across the M104 series.
Production years 1993–1996 meet Euro 2 standards; 1997–1998 models comply with Euro 3 (VCA UK Type Approval #VCA/EMS/5681).
The Mercedes-Benz M104.943 is a 2,799 cc inline-six naturally aspirated engine engineered for executive sedans and coupes (1993–1998). It combines DOHC 24-valve architecture with Bosch LH-Jetronic 2.4 electronic fuel injection to deliver smooth power delivery and long-term reliability. Designed to meet evolving emissions regulations, it balances refinement with mechanical durability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,799 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 89.9 mm × 73.8 mm | |
| Power output | 132 kW (180 PS) @ 5,500 rpm | |
| Torque | 255 Nm @ 4,000 rpm | |
| Fuel system | Bosch LH-Jetronic 2.4 (electronic sequential multi-point fuel injection) | |
| Emissions standard | Euro 2 (1993–1996); Euro 3 (1997–1998) | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Double-row timing chain (non-interference design) | |
| Oil type | SAE 10W-40 (MB 229.1) | |
| Dry weight | 184 kg |
The M104.943 delivers smooth, linear power ideal for relaxed driving but requires strict adherence to 15,000 km oil change intervals using MB 229.1-compliant 10W-40 oil to prevent camshaft wear and lifter noise. The LH-Jetronic fuel system demands clean fuel and regular filter changes to maintain injector performance. Cold-start enrichment issues may arise from ageing control pressure regulators; these are serviceable per factory procedures. While the timing chain is robust, tensioner inspection is recommended beyond 200,000 km. The non-interference design reduces risk of valve damage in case of timing failure, enhancing long-term ownership confidence.
Oil Specs: Requires SAE 10W-40 meeting MB 229.1 specification (Mercedes-Benz SIB 07 05 89). Supersedes API SF/CC classifications.
Emissions: Euro 3 certification applies to 1997–1998 models only (VCA Type Approval #VCA/EMS/5681). Pre-1997 models meet Euro 2 standards.
Power Ratings: Measured under DIN 70020 standards. Output consistent across fuel qualities due to electronic fuel control system.
Mercedes-Benz Technical Information System (TIS): Docs A104-800, A104-810, SIB 07 05 89
VCA Type Approval Database (VCA/EMS/5681)
ISO 1585:1992 Road vehicles — Test code for net power of internal combustion engines
The Mercedes-Benz M104.943 was used across Mercedes-Benz's W124, W210, and C208 platforms with longitudinal mounting. This engine received platform-specific adaptations—longer intake manifolds in the W210 and revised exhaust manifolds in the C208—and from 1993 the updated oil pump and camshaft lubrication system improved durability, creating service part differentiation. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-facing side of the cylinder block, near the timing cover (Mercedes-Benz TIS A104-805). The 7th and 8th digits of the VIN indicate engine type ('10' for M104 series). Pre-1995 models use a square-shaped air flow meter; post-1995 units retain the same external design but feature internal lubrication upgrades. Critical differentiation from M104.983: M104.943 has a 2,799 cc displacement with 132 kW output, while M104.983 is 3,199 cc with 140 kW. Service parts require VIN and production date verification—camshaft and oil pump components differ before and after 08/1993 (Mercedes-Benz SIB 07 05 89).
The M104.943's primary reliability risk is camshaft and lifter wear on pre-1995 builds, with elevated incidence in high-mileage vehicles. Internal Mercedes quality reports from 1995 noted a significant number of engines requiring camshaft replacement before 180,000 km, while UK DVSA MOT records show increased engine noise and oil consumption in affected units. Extended oil intervals and poor lubricant quality accelerate wear, making oil specification and service adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (1993-1998) and UK DVSA failure statistics (1995-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M104943.
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