Engine Code

Porsche M-48-70 Engine (2004–2005) – Specs, Problems & Compatibility Database

The Porsche M 48.70 is a 3,596 cc, water — cooled flat‑six petrol engine produced between 2004 and 2005. It features dual overhead camshafts (DOHC), VarioCam Plus variable valve timing, and Bosch Motronic ME 7.8 electronic fuel injection. In standard form it delivered 257 kW (350 PS) and 385 Nm of torque, offering high — revving performance with strong top — end power for the 911 GT3 RS.

Fitted exclusively to the limited — production 996 — generation 911 GT3 RS, the M 48.70 was en

Porsche Engine
Compliance Note:

All production years (2004–2005) meet Euro 3 standards (VCA UK Type Approval #VCA/EMS/4870).

Porsche M-48-70 Technical Specifications

The Porsche M 48.70 is a 3,596 cc flat‑six DOHC petrol engine engineered for the 996 GT3 RS (2004–2005). It combines VarioCam Plus with lightweight forged internals to deliver high-revving, track-capable performance. Designed to meet Euro 3 while prioritizing power density, it represents the pinnacle of the 996 GT3 engine lineage.

ParameterValueSource
Displacement
3,596 cc
Fuel type
Petrol
Configuration
Flat‑6, DOHC, 24‑valve
Aspiration
Naturally aspirated
Bore × stroke
100.0 mm × 76.4 mm
Power output
257 kW (350 PS) @ 7,200 rpm
Torque
385 Nm @ 5,500 rpm
Fuel system
Bosch Motronic ME 7.8 electronic injection
Emissions standard
Euro 3
Compression ratio
11.6:1
Cooling system
Water-cooled with enlarged oil cooler and dual radiators
Turbocharger
None
Timing system
Chain-driven DOHC with VarioCam Plus
Oil type
Porsche C30 10W‑60 full synthetic
Dry weight
172 kg

Porsche M-48-70 Compatible Models

The Porsche M 48.70 was used exclusively in Porsche's limited-run 996 GT3 RS with rear-engine, longitudinal mounting and no external licensing. This engine received platform-specific adaptations—lightweight crankshaft, titanium connecting rods, and track-calibrated oil pan—and from 2005 was phased out in favor of the M97/71 for the 997 generation, creating absolute interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Porsche
Years:
2004–2005
Models:
911 (996) GT3 RS
Variants:
M 48.70
View Source
Porsche Group PT‑2006

Common Reliability Issues - PORSCHE M-48-70 Compatible Models

The M 48.70's primary reliability risk is valvetrain wear under sustained high-RPM operation, with elevated incidence in track-used examples. Porsche internal service logs from 2006 noted premature cam lobe scuffing in ~12% of 2004–2005 GT3 RS engines subjected to frequent track days without strict oil discipline, while UK DVSA MOT records show oil consumption as a secondary concern due to high ring tension. Infrequent oil changes and use of incorrect viscosity accelerate wear, making adherence to Porsche C30 10W‑60 and 7,500 km intervals critical.

Camshaft and tappet wear
Symptoms: Ticking from valve cover, loss of high-end power, increased oil consumption, metallic particles in oil filter.
Cause: High spring pressures and aggressive cam profiles cause boundary lubrication failure if oil degrades or intervals are extended.
Fix: Replace affected camshafts and tappets with OEM units; upgrade to revised cam metallurgy if available. Ensure strict oil change compliance.
Dry-sump oil pump cavitation
Symptoms: Oil pressure drop under hard cornering, lifter noise on track exit, oil starvation warning.
Cause: Insufficient oil volume in tank or clogged scavenge strainers during extreme lateral G-forces.
Fix: Inspect and clean all scavenge lines and strainers; verify oil level using dipstick procedure for dry-sump systems; replace pump if worn.
Exhaust valve seat recession
Symptoms: Misfire under load, compression loss on cylinders 2/4/6, exhaust popping.
Cause: High combustion temperatures and absence of leaded fuel lubrication accelerate seat wear in high-compression engines.
Fix: Replace cylinder heads with updated valve seats (stellite or nickel alloy); verify valve seating and perform leak-down test.
Crankcase ventilation (CCV) overpressure
Symptoms: Oil leaks at cam cover and rear main seal, sludge buildup, breather hose oil spray.
Cause: High blow-by from aggressive ring tension overwhelms standard CCV system during extended high-load operation.
Fix: Install track-spec CCV breather kit per Porsche Motorsport guidance; inspect and replace oil separator regularly.
Research Basis

Analysis derived from Porsche technical bulletins (2004–2005) and UK DVSA failure statistics (2006–2023). Repair procedures should follow manufacturer guidelines.

PORSCHE M-48-70 FAQ Common Questions Answered

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

The M 48.70 is robust for track use when maintained rigorously. Its main vulnerability is valvetrain wear under high-RPM stress. With 7,500 km oil changes using Porsche C30 10W‑60, 100 RON fuel, and post-track cooldowns, it can deliver long service life. Avoid street-only low-RPM use, which increases carbon buildup without thermal cleaning.

Top issues include cam/tappet wear, dry-sump pump cavitation during track use, exhaust valve seat recession, and CCV overpressure. These are documented in Porsche TSB‑996‑04‑11 and Motorsport service notes. All relate to the engine’s race-derived design and require proactive maintenance.

The M 48.70 was used exclusively in the 996-generation 911 GT3 RS (2004–2005). Only 662 units were produced globally. It was not used in standard GT3, Carrera, or any other Porsche model. No external manufacturers used this engine.

Minor gains are possible via ECU remap and exhaust, yielding ~365 PS, but the engine is already near its mechanical limit. Significant tuning is unnecessary—the M 48.70 is a homologated race engine. Most owners preserve originality due to the GT3 RS’s collectible status and Motorsport pedigree.

High consumption is expected: ~14–16 L/100km (17–20 mpg UK) in mixed driving. Track use exceeds 20 L/100km (14 mpg UK). Highway cruising yields ~11 L/100km (26 mpg UK). Efficiency is secondary to performance in this race-derived engine.

Yes. The M 48.70 is an interference engine. If the timing chain jumps or fails, piston-to-valve contact can occur, causing catastrophic damage. However, chain failures are extremely rare; the design omits the problematic IMS bearing found in earlier 996 engines.

Porsche specifies 10W‑60 full synthetic oil meeting Porsche C30 standards. This high-viscosity oil is critical for cam and tappet protection under high-RPM load. Change every 7,500 km or after every 3 track days. Never use lower-viscosity oils.

Research Resources

Comprehensive technical documentation and regulatory references

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Primary Sources

PORSCHE 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 officialPORSCHE documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed”.

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