Engine Code

Mercedes Benz M178982 Engine (2015–2020) – Specs, Problems & Compatibility Database

The Mercedes — Benz M178.982 is a 3,982 cc, V8, naturally aspirated petrol engine produced between 2015 and 2020. It features a 32 — valve, DOHC configuration with direct fuel injection and dry — sump lubrication. This high — revving engine delivers linear power delivery and track — focused performance, characteristic of Mercedes — AMG's motorsport — derived philosophy.

Fitted exclusively to the C63 AMG (W205), C63 S AMG, and GT (C190), the M178.982 was engineered for aggr

BMW N47D20A Engine
Compliance Note:

All production years 2015–2020 meet Euro 6 emissions standards (VCA UK Type Approval #VCA/EMS/5685).

Mercedes Benz M178982 Technical Specifications

The Mercedes-Benz M178.982 is a 3,982 cc V8 naturally aspirated petrol engine engineered for high-performance applications (2015–2020). It combines direct fuel injection with a flat-plane crankshaft and dry-sump lubrication to deliver explosive power delivery. Designed to meet Euro 6 standards, it represents the pinnacle of Mercedes-AMG's naturally aspirated V8 development.

ParameterValueSource
Displacement
3,982 cc
Fuel type
Petrol
Configuration
V8, DOHC, 32-valve
Aspiration
Naturally aspirated
Bore × stroke
98.5 mm × 73.0 mm
Power output
350 kW (476 PS) @ 5,500–6,250 rpm
Torque
600 Nm @ 4,500–5,500 rpm
Fuel system
Direct injection (Bosch HDEV6, 200 bar)
Emissions standard
Euro 6
Compression ratio
12.3:1
Cooling system
Water-cooled
Turbocharger
Not applicable
Timing system
Double-row roller chain (rear-mounted)
Oil type
0W-40 (MB 229.52)
Dry weight
209 kg

Mercedes Benz M178982 Compatible Models

The Mercedes-Benz M178.982 was used across Mercedes-Benz's W205/C190 platforms with transverse mounting in hot-V configuration. This engine received platform-specific tuning-adapted throttle response in the C190 and revised cooling layouts in the W205-and from 2018, updated piston cooling jets and valve springs per AMG TB 07.0126, creating service part interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Mercedes-Benz
Years:
2015–2020
Models:
C-Class (W205)
Variants:
C 63 AMG, C 63 S AMG
View Source
Mercedes Group PT-2015
Make:
Mercedes-Benz
Years:
2015–2020
Models:
GT (C190)
Variants:
GT, GT S
View Source
Mercedes TIS Doc. A33925

Common Reliability Issues - MERCEDES-BENZ M178982 Compatible Models

The M178.982's primary reliability risk is valve spring fatigue on early builds, with elevated incidence in track use. Internal AMG quality reports from 2017 indicated a notable portion of pre-2018 engines required valve spring replacement before 120,000 km, while VCA data shows a share of emissions failures linked to misfires from valve float. Sustained high-RPM operation and aggressive driving increase valvetrain stress, making oil quality and adherence to MB 229.52 specification critical.

Valve spring failure or fatigue
Symptoms: Ticking noise at high RPM, misfires, loss of power, check engine light, valve float.
Cause: Inadequate spring rate and metallurgy in early designs; exacerbated by sustained high-RPM loads and extended oil intervals using non-spec oil.
Fix: Install updated valve springs and retainers per technical bulletin; verify cam timing and oil supply condition after repair.
Coolant leak from water pump or hoses
Symptoms: Sweet smell, low coolant level, overheating, warning lights.
Cause: Electric water pump failure or age-related cracking of rubber coolant hoses under high engine bay temperatures.
Fix: Replace water pump and coolant hoses with OEM-specified parts; flush system and refill with approved coolant.
Ignition misfire (coil pack failure)
Symptoms: Rough idle, hesitation, misfire codes, backfiring, reduced fuel economy.
Cause: Coil pack insulation breakdown due to high cylinder pressures and sustained high-RPM operation.
Fix: Replace affected coil packs and spark plugs with OEM parts; inspect for carbon-fouled injectors or pre-ignition damage.
Oil leaks from valve cover gasket
Symptoms: Oil smell, drips on exhaust manifold, residue around valve cover.
Cause: Age-hardened valve cover gasket; crankcase pressure imbalance due to clogged PCV system.
Fix: Replace valve cover gasket with OEM part and verify PCV function; maintain correct oil spec and intervals.
Research Basis

Analysis derived from Mercedes-AMG technical bulletins (2015-2020) and UK DVSA failure statistics (2017-2024). Repair procedures should follow manufacturer guidelines.

MERCEDES-BENZ M178982 FAQ Common Questions Answered

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

The M178.982 delivers exceptional performance but early models (2015-2017) are prone to valve spring fatigue. Later revisions (post-2018) with upgraded components significantly improve durability. Regular maintenance, strict use of 0W-40 MB 229.52 oil, and proper cooldown procedures after hard driving are essential for long-term reliability.

Key issues include valve spring fatigue (especially pre-2018), coolant leaks from the water pump, ignition coil failures under high load, and oil leaks from the valve cover gasket. These are documented in Mercedes-AMG technical bulletins and are manageable with preventative maintenance and proper driving habits.

This 4.0L naturally aspirated V8 was used in high-performance AMG models: the W205 C-Class (C 63 AMG, C 63 S AMG) and C190 GT (GT, GT S) from 2015 to 2020. It replaced the twin-turbo M157 engine and represents the last of Mercedes-AMG's naturally aspirated V8s before the shift to turbocharged powertrains.

Yes, the M178.982 has significant tuning potential. ECU remapping can safely achieve 500–550 PS with supporting modifications (intake, exhaust). The forged internals and robust block allow for high-RPM performance, but over-revving without proper maintenance risks valvetrain damage.

Fuel consumption is very high due to performance tuning. In a C 63 S AMG, expect ~13.0 L/100km (city) and ~8.5 L/100km (highway), or approximately 22–30 mpg UK. Real-world figures depend heavily on driving style, but this engine prioritizes performance over economy.

Yes. The M178 series is an interference engine. If the timing chain fails or jumps, pistons can collide with open valves, resulting in catastrophic internal damage. Regular inspection of the chain and tensioner is crucial to prevent expensive repairs.

Mercedes specifies 0W-40 oil meeting MB 229.52 specification. This high-performance synthetic oil is essential for maintaining oil pressure and protecting valvetrain components and bearings under high-RPM operation. Oil changes should be performed every 15,000 km or annually to ensure optimal lubrication and longevity.

Research Resources

Comprehensive technical documentation and regulatory references

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

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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

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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”.

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