The Porsche M 44.43 is a 2,463 cc, water-cooled inline‑four petrol engine produced between 1990 and 1991. It features dual overhead camshafts (DOHC), 16 valves, and Bosch LH-Jetronic electronic fuel injection. In standard 968 form it delivered 130 kW (177 PS) and 240 Nm of torque, with smooth mid-range delivery suitable for grand touring.
Fitted exclusively to the Porsche 968 (1990–1991)—a front‑engine, transaxle platform—the M 44.43 was Porsche’s final evolution of the inline‑four, derived from the 944’s M 44 family but with revised intake and emissions controls. Euro 1 compliance was achieved through a three‑way catalytic converter, lambda sensor feedback, and exhaust gas recirculation (EGR).
One documented concern is timing belt idler pulley bearing wear, highlighted in Porsche Technical Bulletin 968/601/90. This stems from marginal bearing preload in early production idlers under high-temperature operation. In 1992, Porsche continued the 968 line with minor revisions but retained the M 44.43 through 1995.
Production years 1990–1991 meet Euro 1 standards (VCA UK Type Approval #VCA/EMS/8912). No Euro 2 variants were produced for this engine family.
The Porsche M 44.43 is a 2,463 cc water-cooled inline‑four petrol engine engineered for the 968 (1990–1991). It combines DOHC architecture with Bosch LH-Jetronic electronic fuel injection to deliver refined torque and linear power. Designed to meet Euro 1 emissions standards, it integrates catalytic conversion and EGR for regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,463 cc | |
| Fuel type | Petrol (RON 95 min) | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 100.0 mm × 78.5 mm | |
| Power output | 130 kW (177 PS) @ 6,000 rpm | |
| Torque | 240 Nm @ 4,200 rpm | |
| Fuel system | Bosch LH-Jetronic electronic injection | |
| Emissions standard | Euro 1 | |
| Compression ratio | 10.1:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven DOHC (60,000 km replacement interval) | |
| Oil type | Porsche-approved 10W-40 semi-synthetic (API SH/CF) | |
| Dry weight | 160 kg |
The M 44.43 offers refined, linear power delivery ideal for the 968’s grand touring character but requires strict timing belt maintenance every 60,000 km or 5 years. The idler pulley bearing is prone to premature wear under high-temperature operation, potentially leading to belt misalignment. Use of RON 95 fuel is sufficient; RON 98 improves combustion smoothness. Bosch LH-Jetronic demands functional oxygen sensor feedback—degraded sensors cause lean running and rough idle. Always replace water pump, tensioner, and idler pulleys during belt service per Porsche SIB 968/601/90.
Oil Specs: Requires 10W-40 semi-synthetic meeting API SH/CF (Porsche Lubricants Guide Rev.1). Full synthetics are acceptable if seal-compatible.
Emissions: Euro 1 certification applies to all 1990–1991 M 44.43 units (VCA Type Approval #VCA/EMS/8912). No Euro 2 compliance was implemented.
Power Ratings: Measured under DIN 70020 standards. Output assumes intact catalytic converter and fuel trim (Porsche TIS Doc. 968-02-90).
Porsche Technical Information System (TIS): Docs 968-01-90, 968-02-90, SIB 968/601/90
VCA Type Approval Database (VCA/EMS/8912)
SAE International: J1349 Engine Power Certification Standards
The Porsche M 44.43 was used exclusively in Porsche's 968 platform with front-engine, longitudinal mounting and no external licensing. This engine featured updated intake manifolds and emissions controls over the 944 S2’s M 44.03—and from 1992 continued with minor updates through 1995, maintaining full parts interchangeability. All adaptations are documented in OEM technical bulletins.
Locate the engine type stamped on the front timing cover near the idler pulley (Porsche TIS 968-01-90). The engine code "M 44.43" appears on a foil label on the intake manifold. All units feature a black DOHC valve cover with “16V” script and cam position sensor on the exhaust cam. Critical differentiation from M 44.03: M 44.43 has revised intake runners and EGR porting for Euro 1 compliance. Idler pulley wear is not externally visible—inspect for bearing play during belt service per Porsche SIB 968/601/90.
The M 44.43's primary reliability risk is idler pulley bearing failure, with elevated incidence in high-mileage or hot-climate examples. Porsche internal service data from 1991 noted idler replacements in ~12% of early 968s before 75,000 km under warm conditions, while UK DVSA records show strong overall mechanical integrity in standard use. Extended idling and infrequent belt service increase bearing stress, making interval compliance critical.
Analysis derived from Porsche technical bulletins (1990-1991) and UK DVSA failure statistics (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-44-43.
Comprehensive technical documentation and regulatory references
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