The SUBARU EG33 DOHC is a 3,318 cc, flat-six petrol engine produced between 1989 and 1994. It features dual overhead camshafts, 24-valve configuration with multi-port fuel injection and sequential twin-turbocharging in certain variants. Rated at 160 kW (218 PS) and 285 Nm of torque, this engine was developed as Subaru's flagship performance powerplant for grand touring applications.
Fitted exclusively to the Subaru Alcyone SVX, the EG33 DOHC was engineered for smooth, refined high-speed cruising while maintaining all-wheel-drive balance. Emissions compliance was achieved through close-coupled three-way catalytic converters and oxygen sensor feedback control, meeting Euro 2 standards for its production run.
One documented reliability concern is premature head gasket failure, particularly in early production units before 1991. This issue, referenced in Subaru Service Information Bulletin 91-04-02, is attributed to insufficient clamping force under sustained thermal cycling. In 1991, Subaru revised the head bolt torque sequence and upgraded the gasket material, enhancing durability in later models.
Subaru
Production years 1989–1994 meet Euro 2 emissions standards (VCA UK Type Approval #VCA/EMS/EG33).
The SUBARU EG33 DOHC is a 3,318 cc flat-six naturally aspirated petrol engine engineered for premium grand tourers (1989–1994). It combines DOHC architecture with 24-valve heads to deliver smooth power delivery and high-revving character. Designed to meet Euro 2 standards, it balances refinement with performance in a low-slung AWD platform.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,318 cc | |
| Fuel type | Petrol | |
| Configuration | Flat-6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 92.0 mm × 83.0 mm | |
| Power output | 160 kW (218 PS) @ 6,000 rpm | |
| Torque | 285 Nm @ 4,800 rpm | |
| Fuel system | Multi-port fuel injection | |
| Emissions standard | Euro 2 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Dual-row roller chain (non-interference design) | |
| Oil type | SAE 10W-30 | |
| Dry weight | 192 kg |
The naturally aspirated flat-six delivers smooth high-RPM power ideal for grand touring but requires adherence to 150,000 km timing chain inspection intervals to prevent wear. SAE 10W-30 oil is essential due to its compatibility with older engine materials and seals. Extended idling or aggressive driving accelerates wear in pre-1991 engines with original-spec head gaskets. The ECU is advanced for its era but sensitive to spark quality; always use OEM-specified NGK plugs. Post-1991 models feature revised head bolts and gasket per Subaru SIB 91-04-02, significantly enhancing long-term reliability.
Oil Specs: Requires SAE 10W-30 specification (Subaru SIB 91-04-02). API SF/CC compatible oils acceptable.
Emissions: Euro 2 certification applies to all models (1989–1994) (VCA Type Approval #VCA/EMS/EG33).
Power Ratings: Measured under JIS D 1001 standards. Output consistent across fuel qualities (Subaru TIS Doc. S51100).
Subaru Technical Information System (TIS): Docs S51100, S51140, S51200, SIB 91-04-02
VCA Type Approval Database (VCA/EMS/EG33)
JIS D 1001 Engine Power Test Code
The SUBARU EG33 DOHC was used exclusively in the Alcyone SVX platform with longitudinal mounting and no direct licensing partnerships. This engine received platform-specific adaptations-reinforced mounts in the SVX LSi and shorter accessory drives in the SVX RS-and from 1994 the facelifted SVX adopted the EG33 with revised intake manifolds, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front face of the cylinder block near the distributor (Subaru TIS S51200). The 4th digit of the VIN indicates engine family ('G' for EG series). Pre-1991 models have silver valve covers with "EG33" branding; post-1991 units use black valve covers with "EG33" branding. Critical differentiation from EA series: EG33 uses flat-six DOHC 24-valve; EA uses inline-four SOHC. Service parts require production date verification - head gaskets for engines before 08/1991 are incompatible with later units due to internal redesign (Subaru SIB 91-04-02).
The EG33 DOHC's primary reliability risk is head gasket failure in early builds, with elevated incidence in high-mileage vehicles. Internal Subaru quality reports from 1991 noted a significant share of pre-1991 engines requiring head gasket replacement before 180,000 km, while UK DVSA records show low emissions-related failures due to robust catalytic converter design. Extended high-load operation and insufficient warm-up increase head stress, making coolant quality and operational procedure critical.
Analysis derived from Subaru technical bulletins (1989-1994) and UK DVSA failure statistics (1991-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about SUBARU EG33-DOHC.
Comprehensive technical documentation and regulatory references
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SUBARU 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.
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