The Mercedes — Benz M104.992 is a 3,598 cc, inline — six naturally aspirated petrol engine produced between 1997 and 2000. It was developed by AMG as a high — performance variant of the M104 series for use in Mercedes — Benz's premium performance sedans and coupes. Featuring a dual overhead camshaft (DOHC), 24 — valve head, and individual throttle bodies, it produced 243 kW (330 PS) at 6,000 rpm and 375 Nm of torque at 5,000 rpm.
Fitted exclusively to the W202 C — Class and C208 CLK —…
All production years (1997–2000) meet Euro 3 emissions standards (VCA UK Type Approval #VCA/EMS/5682).
The Mercedes-Benz M104.992 (AMG 3.6) is a 3,598 cc inline-six naturally aspirated engine engineered for high-performance applications (1997–2000). It combines DOHC 24-valve architecture with individual throttle bodies to deliver aggressive power delivery and high-RPM capability. Designed for AMG-tuned vehicles, it prioritizes performance and driving engagement while meeting Euro 3 emissions requirements.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,598 cc | |
Fuel type | Petrol | |
Configuration | Inline-6, DOHC, 24-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 89.9 mm × 94.0 mm | |
Power output | 243 kW (330 PS) @ 6,000 rpm | |
Torque | 375 Nm @ 5,000 rpm | |
Fuel system | Sequential multi-port fuel injection (KE-Motronic) | |
Emissions standard | Euro 3 | |
Compression ratio | 10.8:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Chain-driven camshafts (double-row, duplex chain) | |
Oil type | SAE 10W-60 MB 229.3 | |
Dry weight | 192 kg |
The Mercedes-Benz M104.992 was used exclusively in Mercedes-Benz's W202 and C208 platforms with longitudinal mounting and no licensed external applications. This engine received model-specific tuning—higher-lift camshafts in the C208 and revised intake plenums in the W202—and from 1998 incorporated updated valve train components per AMG engineering directives, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The M104.992's primary reliability risk is timing chain wear under high-RPM use, with elevated incidence in performance-driven or poorly maintained vehicles. Mercedes-Benz service data from 1999 indicated timing chain guide wear in approximately 30% of high-mileage units, while UK DVSA MoT records show oil leaks as a frequent cause of engine bay contamination in classic AMG models. Extended high-load operation and infrequent oil changes accelerate wear, making adherence to AMG service intervals critical.
Analysis derived from Mercedes-Benz technical bulletins (1997-2000) and UK DVSA failure statistics (1995-2005). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
Yes, the M104.992 is mechanically robust and capable of high mileage when properly maintained. Its iron block and DOHC 24-valve design contribute to performance longevity. The main weaknesses are timing chain guide wear and valve cover gasket leaks. Regular oil changes with MB 229.3 spec oil and timely replacement of ageing components ensure reliable operation beyond 200,000 km in performance applications.
The most frequent issues are timing chain guide wear, valve cover gasket leaks, ignition coil pack failures, and coolant leaks from the thermostat housing. These are well-documented in Mercedes-Benz service literature. Preventative maintenance on high-temperature seals and periodic inspection of the timing system are key to avoiding major repairs.
The M104.992 was used in the W202 C-Class (C36 AMG) from 1997 to 2000 and the C208 CLK-Class (CLK320 AMG) from 1998 to 2000. It was not used in E-Class or SL-Class platforms. All applications were naturally aspirated and paired with rear-wheel drive and 5-speed automatic transmissions.
Significant power gains are limited due to the naturally aspirated design, but performance upgrades include high-flow exhaust systems, performance camshafts, and ECU remapping. Individual throttle bodies already optimize airflow, so gains are modest. Realistic increases are 20-30 hp with supporting modifications. Classic AMG tuning focuses on refinement and drivability rather than extreme power output.
In a W202 C36 AMG, typical consumption is ~16.0 L/100km (city) and ~9.5 L/100km (highway), or about 18 mpg UK combined. The KE-Motronic system is efficient for a high-performance inline-six, but real-world figures depend heavily on driving style. Expect 16-20 mpg (UK) in mixed driving for a well-maintained example.
Yes. The M104.992 is an interference engine. If the timing chain fails or jumps, the pistons can contact the valves, causing severe internal damage. This design enhances performance but increases repair costs in the event of timing component failure. Prompt inspection and replacement of worn guides are essential.
Mercedes-Benz specifies SAE 10W-60 oil meeting MB 229.3 specification. Use a high-quality synthetic oil designed for high-performance engines. Change intervals should not exceed 15,000 km or annually to ensure proper camshaft and chain lubrication, especially important for long-term durability under performance use.
Comprehensive technical documentation and regulatory references
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.
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.
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.
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.
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
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
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
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.
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.
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.