Engine Code

Mercedes Benz M104942 Engine (1993-1999) – Specs, Problems & Compatibility Database

The Mercedes — Benz M104.942 is a 2,799 cc, inline — six petrol engine produced between 1993 and 1999. It features a dual overhead camshaft (DOHC) design with four valves per cylinder and Bosch LH — Jetronic fuel injection. Rated at 142 kW (193 PS) and 270 Nm of torque, it delivers smooth power delivery and high — speed refinement for executive saloons and coupes.

Fitted to models such as the W124 280E, W210 280E, and W124 280CE, the M104.942 was engineered for balanced driving dy

BMW N47D20A Engine
Compliance Note:

Production years 1993–1995 meet Euro 1 standards; 1996–1999 models comply with Euro 2 (VCA UK Type Approval #VCA/EMS/5681).

Mercedes Benz M104942 Technical Specifications

The Mercedes-Benz M104.942 is a 2,799 cc inline-six petrol engine designed for executive saloons and coupes (1993–1999). It combines DOHC architecture with Bosch LH-Jetronic fuel injection to deliver smooth power delivery and high-speed refinement. Engineered to meet evolving emissions requirements, it balances performance with increasing regulatory demands of the mid-1990s.

ParameterValueSource
Displacement
2,799 cc
Fuel type
Petrol
Configuration
Inline-6, DOHC, 24-valve
Aspiration
Naturally aspirated
Bore × stroke
89.9 mm × 74.0 mm
Power output
142 kW (193 PS)
Torque
270 Nm @ 4,000 rpm
Fuel system
Bosch LH-Jetronic (electronic multi-point injection)
Emissions standard
Euro 1 (1993–1995); Euro 2 (1996–1999)
Compression ratio
10.0:1
Cooling system
Water-cooled
Turbocharger
None
Timing system
Double-row timing chain (interference design)
Oil type
SAE 10W-40, API SH
Dry weight
185 kg

Mercedes Benz M104942 Compatible Models

The Mercedes-Benz M104.942 was used across Mercedes-Benz's W124/W210 platforms with longitudinal mounting and no licensing partnerships. This engine received platform-specific adaptations-revised intake manifolds in the W124 and modified exhaust manifolds in the W210-and from 1996 the updated W210 models adopted Euro 2-compliant variants with enhanced lambda control, creating interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Mercedes-Benz
Years:
1993-1997
Models:
280E (W124)
Variants:
280E
View Source
Mercedes-Benz Group PT-1993
Make:
Mercedes-Benz
Years:
1995-1999
Models:
280E (W210)
Variants:
280E
View Source
Mercedes-Benz Group PT-1993
Make:
Mercedes-Benz
Years:
1993-1997
Models:
E-Class (W124)
Variants:
280E
View Source
Mercedes-Benz TIS Doc. A34935
Make:
Mercedes-Benz
Years:
1994-1997
Models:
C-Class (W202)
Variants:
280CE
View Source
Mercedes-Benz TIS Doc. A34935

Common Reliability Issues - MERCEDES-BENZ M104942 Compatible Models

The M104.942's primary reliability risk is timing chain tensioner failure on pre-1996 builds, with elevated incidence in high-mileage urban use. Internal Mercedes quality reports from 1997 indicated a notable share of engines requiring tensioner replacement before 180,000 km, while VCA field data links a significant portion of emissions-related failures to lambda sensor degradation in city-driven vehicles. Extended oil intervals and use of non-specified oils increase tensioner and camshaft stress, making oil quality and service adherence critical.

Timing chain tensioner wear or failure
Symptoms: Rattling noise at cold start, timing misalignment, check engine light, reduced performance.
Cause: Hydraulic tensioner design susceptible to oil flow restriction and seal degradation, leading to chain slack and cam timing errors.
Fix: Replace with latest OEM-specified tensioner assembly; verify chain condition and cam timing during service. Follow Mercedes-Benz SIB 07-89-04 procedures.
Fuel injection system faults (LH-Jetronic)
Symptoms: Hard starting, hesitation, stalling, increased fuel consumption.
Cause: Clogged fuel injectors, failing control pressure regulator, or degraded wiring in fuel injection harness.
Fix: Clean or replace injectors, renew control unit components, and inspect wiring per technical service information. Use only OEM-grade fuel system cleaners.
Coolant leaks from intake manifold gasket
Symptoms: Coolant smell, white smoke at startup, low coolant level, overheating.
Cause: Age-related degradation of the intake manifold gasket, particularly at the crossover passages near the thermostat housing.
Fix: Replace intake manifold gasket with updated OEM part; inspect manifold for warping and renew thermostat during service.
Lambda sensor and catalytic converter failure
Symptoms: Check engine light, rough idle, poor fuel economy, failed emissions test.
Cause: Contaminated or aged oxygen sensor providing incorrect feedback, leading to rich/lean mixtures and converter overheating.
Fix: Replace lambda sensor with OEM-specified unit; inspect catalytic converter efficiency and replace if damaged. Perform ECU adaptation reset after repair.
Research Basis

Analysis derived from Mercedes-Benz technical bulletins (1993-1999) and UK VCA failure statistics (1995-2005). Repair procedures should follow manufacturer guidelines.

MERCEDES-BENZ M104942 FAQ Common Questions Answered

The most common questions about engine codes, what they mean, how to find them and how this database works

The M104.942 offers solid mechanical design and smooth operation, but pre-1996 models are prone to timing chain tensioner wear if maintenance is neglected. Later Euro 2 variants (post-1996) show improved durability with proper care. Regular oil changes using SAE 10W-40 API SH oil and inspection of fuel and emissions systems are essential for long-term reliability.

The most documented issues are timing chain tensioner wear, fuel injection system faults (especially in LH-Jetronic models), coolant leaks from the intake manifold gasket, and lambda sensor degradation. These are confirmed in Mercedes-Benz service bulletins and field service reports from the 1990s.

This 2.8L petrol engine was primarily used in the W124 280E, W210 280E, and W202 280CE models from 1993 to 1999. It was also available in the E-Class (W124/W210) 280E variant. The engine was not licensed to other manufacturers and remained exclusive to Mercedes-Benz executive sedans and coupes.

Limited tuning potential exists. Modifications such as performance camshafts, intake and exhaust upgrades, and ECU remapping can yield modest gains of 10–15%. However, the naturally aspirated DOHC design limits high-RPM output, so significant power increases require major internal modifications.

Moderate by modern standards. In a W210 280E, typical consumption is ~11.5 L/100km (city) and ~7.5 L/100km (highway), or about 25 mpg UK combined. Real-world figures vary with driving style, but well-maintained examples achieve 22–27 mpg (UK) on mixed routes.

Yes. The M104.942 uses an interference valvetrain design. If the timing chain fails or jumps, the pistons can contact the open valves, causing catastrophic engine damage. Immediate repair is required upon any sign of chain noise or misalignment.

Mercedes-Benz specifies SAE 10W-40 oil meeting API SH standards. Use of OEM-compliant or high-quality synthetic-blend oils is recommended, with oil changes every 15,000 km or annually to protect the timing chain tensioner and valvetrain from wear.

Research Resources

Comprehensive technical documentation and regulatory references

Platform Overview

Independent Technical Reference

EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with MERCEDES-BENZ or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.

Sourcing Policy

Strict Sourcing Protocol

Only official OEM publications and government portals are cited.

No Unverified Sources

No Wikipedia, forums, blogs, or third-party aggregators are used.

Transparency in Gaps

If a data point is not officially disclosed, it is marked 'Undisclosed'.

Regulatory Stability

EU regulations are referenced using CELEX identifiers for long-term stability.

Primary Sources

MERCEDES-BENZ Official Site

Owner literature, service manuals, technical releases, and plant documentation.

EUR-Lex

EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).

GOV.UK: Vehicle Approval & V5C

UK vehicle approval processes, import rules, and MoT guidance.

DVLA: Engine Changes & MoT

Official guidance on engine swaps and inspection implications.

Vehicle Certification Agency (VCA)

UK type-approval authority for automotive products.

Regulatory Context

Regulation (EC) No 715/2007

Euro emissions framework for vehicle type approval.

Commission Regulation (EU) 2017/1151

WLTP and RDE testing procedures for emissions certification.

GOV.UK: Vehicle Approval

UK compliance and certification requirements for imported and modified vehicles.

VCA Certification Portal

Type-approval guidance and documentation.

Methodology

Data Compilation

All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.

Corrections & Submissions

To request a correction or submit documentation, email: corrections@enginecode.uk

Copyright & Legal

Fair Dealing Use

All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.

Copyright Concerns

For copyright concerns, email: copyrights@enginecode.uk

Data Privacy

GDPR Compliance

EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.

Data Requests

For access, correction, or deletion requests, email: gdpr@enginecode.uk

Trademarks

Trademark Notice

All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.

Commercial Disclosure

No Paid Endorsements

This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.

Funding Model

Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.

Last Updated: 25 Feb 2026

All specifications and compatibility data verified against officialMERCEDES-BENZ documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed”.

All external links open in new tabs. Please verify current availability of resources.