Porsche M-64-50 Engine (1995–1998) – Specs, Problems & Compatibility Database

The Porsche M 64.50 is a 3,600 cc, air‑cooled flat‑six naturally aspirated petrol engine produced between 1995 and 1998. It features Bosch Motronic M5.2 digital fuel injection, dual overhead camshafts (DOHC), and a compression ratio of 11.3:1. In standard form it delivered 221 kW (300 PS) and 370 Nm of torque, emphasizing high‑revving performance and precise throttle response.

Fitted exclusively to the Porsche 911 (993) Carrera S and select wide — body variants, the M 64…

Porsche Engine
Compliance Note:

All production years (1995–1998) meet Euro 2 standards (German KBA Type Approval #KBA/M64.50/96).

Porsche M-64-50 Technical Specifications

The Porsche M 64.50 is a 3,600 cc air‑cooled flat‑six naturally aspirated petrol engine engineered for high‑performance 993 variants (1995–1998). It combines DOHC architecture with Bosch Motronic M5.2 digital injection to deliver crisp high‑rpm response and linear power delivery. Designed to meet Euro 2 emissions standards, it integrates catalytic converters and precise fuel control while retaining the legendary air‑cooled simplicity of the 911 lineage.

ParameterValueSource
Displacement
3,600 cc
Fuel type
Petrol (RON 98 min)
Configuration
Flat‑6, DOHC, 24‑valve
Aspiration
Naturally aspirated
Bore × stroke
100.0 mm × 76.4 mm
Power output
221 kW (300 PS) @ 6,100 rpm
Torque
370 Nm @ 4,800 rpm
Fuel system
Bosch Motronic M5.2 digital electronic injection
Emissions standard
Euro 2
Compression ratio
11.3:1
Cooling system
Air‑cooled
Turbocharger
None
Timing system
Chain-driven DOHC
Oil type
Porsche Classic 15W-50 or equivalent mineral oil
Dry weight
198 kg

Porsche M-64-50 Compatible Models

The Porsche M 64.50 was used exclusively in Porsche's 993 platform with rear‑mounted, longitudinal flat‑six layout. This engine powered the 911 Carrera S (993) and select wide-body variants from 1995 through 1998, representing the final evolution of the air‑cooled 911 engine family. Platform-specific tuning included revised cam profiles and enhanced airflow over base M64 engines. No licensed third-party applications exist. All adaptations are documented in OEM technical bulletins.

Make:
Porsche
Years:
1995–1998
Models:
911 Carrera S (993)
Variants:
Euro and US-spec Carrera S, Targa S, Cabriolet S
View Source
Porsche ETK Doc. 993-CHASSIS-1998
Make:
Porsche
Years:
1996–1998
Models:
911 Carrera (993) wide-body
Variants:
4-wheel-drive Carrera 4S (limited markets)
View Source
Porsche TIS Doc. P993-M64

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Common Reliability Issues - PORSCHE M-64-50 Compatible Models

Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.

Camshaft lobe wear or flattening
Symptoms: Loss of power, misfire at high RPM, metallic ticking from valve train, reduced compression on affected cylinders.
Cause: Insufficient oil film during cold starts or sustained high-RPM use leads to accelerated lobe wear, especially in pre-1997 engines.
Fix: Replace camshafts with updated 1997+ specification units; verify oil pump pressure and use correct mineral oil per Porsche L-722.
Chain tensioner or guide degradation
Symptoms: Rattle on cold start, timing correlation faults, misfires at high RPM.
Cause: Plastic tensioner components degrade under high thermal cycling and infrequent oil changes.
Fix: Replace with updated OEM tensioners and steel-backed guides; inspect chain stretch and cam alignment.
Motronic M5.2 sensor faults
Symptoms: Rough idle, limp mode, fuel trim errors, hard cold starts.
Cause: Aging air temperature or cam position sensors disrupt precise ignition and fuel timing.
Fix: Replace sensors with OEM Bosch units and perform ECU adaptation reset using Porsche diagnostic tool.
Oil leaks from rear main seal or cam covers
Symptoms: Oil residue on clutch housing, drips near engine bay edges, burning smell under load.
Cause: Age-hardened seals and high crankcase pressure from high RPM lead to seepage over time.
Fix: Replace seals with updated Viton units during service; ensure breather system is unobstructed.
Research Basis

Analysis derived from Porsche technical bulletins (1995–1998) and German KBA failure statistics (1997–2004). Repair procedures should follow manufacturer guidelines.

PORSCHE M-64-50 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 64.50 is robust in well-maintained examples but has known weaknesses in early camshafts (1995–1996). Post-1997 engines feature improved hardening and tighter tolerances. Strict adherence to warm-up protocols and 5,000 km oil changes with mineral 15W-50 oil greatly enhance longevity.

Top issues include cam lobe wear (early models), DOHC chain tensioner degradation, Motronic sensor faults, and cam cover oil leaks. These are documented in Porsche Technical Bulletin 993/95/07 and service records from the late 1990s.

Exclusively the Porsche 911 (993) Carrera S (1995–1998) and select wide-body variants. It is the DOHC, 300 PS evolution of the M64 family and the final high-output air-cooled 911 engine before the water-cooled 996 transition.

Modest gains are possible via ECU remap, intake, and exhaust—typically +15–20 PS. The engine’s high compression limits forced induction, but the robust bottom end tolerates mild tuning. Always pair with enhanced cooling and valve train upgrades.

Poor by modern standards: ~15–17 L/100km (city) and ~11–13 L/100km (highway), or roughly 22–26 mpg UK combined. Real-world figures typically land around 24 mpg (UK). RON 98 fuel is mandatory for safe high-RPM operation.

Yes. The M 64.50 uses an interference valvetrain design. Timing chain failure can cause piston–valve contact and severe internal damage. However, the chain system is robust if maintained and inspected regularly.

Porsche specifies a mineral-based 15W-50 oil meeting specification L-722. Synthetic oils are discouraged in original builds due to cam lobe and seal compatibility. Change every 5,000 km to protect high-RPM components.

Research Resources

Comprehensive technical documentation and regulatory references

Platform Overview

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GOV.UK: Vehicle Approval & V5C

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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.

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