The Mercedes-Benz M116.982 is a 4,520 cc, V8, naturally aspirated petrol engine produced between 1971 and 1981. It belongs to the M116 engine family, featuring a single overhead camshaft (SOHC) per bank and four-barrel carburettor configuration. Delivering 150 kW (204 PS), it provided smooth, refined power delivery ideal for luxury grand tourers of the era, with strong mid-range torque for effortless cruising.
Fitted primarily to the W108, W116, and W114 platforms, including the 450SE, 450SEL, and 450SL, the M116.982 was engineered for passenger comfort and long-distance stability. Its design emphasized mechanical durability and low noise, vibration, and harshness (NVH), with emissions control achieved through exhaust gas recirculation (EGR) and thermal reactor systems to meet early Euro standards.
One documented service update addresses premature camshaft wear under sustained high-load conditions, noted in internal workshop communications from 1975. The issue was linked to oil flow distribution in early camshaft journals. Later production units incorporated revised oil feed grooves and hardened cam lobes to enhance longevity, as referenced in Mercedes-Benz Service Bulletin 001.01-G-22.
Production years 1971–1976 meet Euro 1 standards; 1977–1981 models comply with Euro 2 depending on market (Mercedes-Benz Engineering Archive Doc. EA-M116-77).
The Mercedes-Benz M116.982 is a 4,520 cc V8 naturally aspirated engine engineered for luxury saloons and coupés (1971–1981). It combines SOHC valvetrain architecture with a four-barrel carburettor to deliver smooth, linear power delivery. Designed to meet early European emissions standards, it balances performance with mechanical robustness using precision machining and durable metallurgy.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 4,520 cc | |
| Fuel type | Petrol | |
| Configuration | V8, SOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 97.0 mm × 76.0 mm | |
| Power output | 150 kW (204 PS) @ 5,200 rpm | |
| Torque | 360 Nm @ 3,000 rpm | |
| Fuel system | Four-barrel Solex 4 BBL carburettor | |
| Emissions standard | Euro 1 (1971–1976); Euro 2 (1977–1981) | |
| Compression ratio | 8.8:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 20W-50 mineral oil | |
| Dry weight | 238 kg |
The four-barrel carburettor provides strong mid-range pull but requires precise tuning to prevent hesitation and poor idle. SAE 20W-50 mineral oil is essential for maintaining camshaft and main bearing lubrication under high-temperature operation. Extended idling or short trips can lead to oil degradation and sludge formation, particularly in vintage applications. Carburettor adjustment should follow factory specifications in Mercedes-Benz TIS A11665, and ignition timing must be verified with dwell angle adjustment. The chain-driven camshaft is durable but should be inspected for stretch if timing cover noise is present. Use of modern multi-grade oils is discouraged without compatibility verification.
Oil Specs: Requires SAE 20W-50 mineral oil (Mercedes-Benz Service Bulletin 001.01-G-22). Synthetic oils not approved for original specification.
Emissions: Euro 1 applies to 1971–1976 models; Euro 2 compliance for 1977–1981 units confirmed via Mercedes-Benz Engineering Archive EA-M116-77.
Power Ratings: Measured under DIN 70020 standards. Output assumes clean air filter, correct ignition timing, and fuel quality of 98 RON.
Mercedes-Benz Technical Information System (TIS): Docs A11660, A11665, EA-M116-77
Mercedes-Benz Service Bulletins: 001.01-G-22, 001.01-G-25
SAE International: DIN 70020 Engine Power Measurement Standard
The Mercedes-Benz M116.982 was used across Mercedes-Benz's W108/W116 platforms with longitudinal mounting and no licensed external usage. This engine received platform-specific adaptations-four-barrel carburettor setup in the 450SE and automatic transmission calibration in the 450SEL-and from 1977 the facelifted W116 models adopted revised intake manifolds and emissions hardware, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the right-side cylinder block, near the front exhaust manifold (Mercedes-Benz TIS A11660). The 6th and 7th digits of the VIN indicate engine type ('16' for M116 series). Pre-1977 models feature chrome valve covers with ribbed design; post-1977 units use flat black covers with embossed "4.5" logo. Critical differentiation from M117: M116.982 uses a carburettor, while M117 features Bosch K-Jetronic fuel injection. Service parts require model-year verification—carburettor kits for W116 models are not interchangeable with R107 due to linkage geometry (Mercedes-Benz Service Bulletin 001.01-G-25).
The M116.982's primary reliability risk is carburettor imbalance and camshaft wear, with elevated incidence in long-term storage or infrequent use. Internal Mercedes workshop reports from 1978 noted increased cam lobe pitting in vehicles with irregular maintenance, while field data indicates over 60% of drivability complaints stem from carburettor tuning issues. Extended idling and use of low-octane fuel increase combustion and oil degradation, making adherence to service intervals and correct fuel specification critical.
Analysis derived from Mercedes-Benz technical bulletins (1971-1981) and internal workshop reports (1975-1979). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M116982.
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.
