Subaru EJ25 Engine for Sale: The Right Engine for Your Vehicle
This used Subaru EJ25 engine for sale suits Subaru enthusiasts and anyone looking to upgrade or install a new powerplant in their car. The boxer configuration has been synonymous with Subaru reliability and performance potential for decades, across many Subaru models. Additionally, due to its flat-four (horizontally opposed) configuration, the EJ25 lowers the vehicle’s center of gravity, improving handling and stability.
The Subaru EJ25 engine for sale here has proven versatile across its 26-year production run , it powers everything from daily-driver Foresters and Outbacks (NA SOHC variants like the EJ251 and EJ253) up to high-performance WRX and STI applications (turbocharged DOHC variants like the EJ255 and EJ257). With a thriving aftermarket to back up owner choices for parts and upgrades, this boxer engine’s distinct rumble and brawny construction have solidified its fame among Subaru fans worldwide.
Important Configuration Clarification
The live product page description states the EJ25 is an “inline 4-cylinder” , this is incorrect. The EJ25 is a flat-4 (horizontally opposed) boxer engine, NOT an inline-4. The cylinders are arranged horizontally in two banks of two, with each bank facing outward to opposite sides of the vehicle. This is Subaru’s signature engine configuration and produces the characteristic “Subaru rumble” sound.
Subaru EJ25 Engine Family: What You Need to Know
The Subaru EJ25 is the 2.5 liter member of Subaru’s broader EJ-series flat-4 boxer engine family. The EJ25 was produced in multiple variants across a 26-year production run (1995-2021), with both naturally aspirated and turbocharged configurations.
EJ25 Variant Breakdown
NA SOHC Variants (Standard Subaru Applications)
EJ251 (1999-2004)
HP: 165 HP at 5,600 RPM
Torque: 166 lb-ft at 4,000 RPM
Valvetrain: SOHC per bank, 16 valves
Compression: 10.0:1
Common Applications: Impreza (1999-2004), Forester (1999-2003), Outback (1999-2004), Legacy (1999-2004)
GSC: “ej251 hp” #1 RANKING, “ej251 for sale” pos 19.0
EJ252 (1995-1999, less common)
Earlier 2.5L SOHC variant
HP: 165 HP
EJ253 (2005-2013)
HP: 173 HP at 6,000 RPM
Torque: 166-170 lb-ft at 4,000 RPM
Valvetrain: SOHC per bank, 16 valves with AVLS (Active Valve Lift System) on some variants
Common Applications: Impreza (2005-2011), Forester (2006-2010), Outback (2005-2009), Legacy (2005-2009), Baja (2006)
Updated EJ251 with refined combustion and emissions
NA DOHC Variants (Limited)
EJ254 (1997-2003)
DOHC NA variant
Used in some Outback / Legacy GT applications
Less common
Turbocharged DOHC Variants (Performance Subaru Applications)
EJ255 (2002-2014)
HP: 227-255 HP (varies by year and application)
Torque: 217-244 lb-ft
Valvetrain: DOHC per bank, 16 valves with AVCS variable valve timing
Turbocharger: IHI VF series with intercooler
Common Applications: WRX (2002-2014), Forester XT (2004-2013), Legacy GT (2005-2009)
EJ257 (2004-2021)
HP: 300-305 HP at 6,000-6,400 RPM , the WRX STI engine
Torque: 290 lb-ft at 4,000 RPM
Valvetrain: DOHC per bank, 16 valves with AVCS
Turbocharger: Larger IHI VF series or aftermarket
Common Applications: WRX STI (2004-2021)
GSC: “cosworth ej257” pos 2.3, “ej257 for sale” pos 19.7, “ej257 crate engine” pos 17.8
Cosworth EJ257
Special performance variant produced through Subaru / Cosworth partnership
Forged internals (crankshaft, connecting rods, pistons)
Closed-deck block (vs open-deck stock) for higher boost capability
Power potential: 400-500+ HP with proper supporting modifications
Highly desired for serious performance builds
Strong GSC presence: “cosworth ej257” pos 2.3
EJ25 Variants Summary Chart
Key Engineering Features
Flat-4 (Horizontally Opposed) Boxer Configuration: Lower center of gravity, smoother than inline-4
Open-Deck Aluminum Block: Lighter weight, but contributing factor in head gasket issues on NA variants
Aluminum Cylinder Heads: All variants
SOHC or DOHC Per Bank: Variant-dependent
AVCS Variable Valve Timing: Standard on later DOHC variants (EJ255 / EJ257 from various years)
Sequential Multi-Port Fuel Injection: All variants (some late applications direct injection)
Longitudinal Mount: Engine mounted lengthwise, paired with Subaru’s symmetrical AWD
Honest Disclosure: Head Gasket Service Items (NA EJ25 Variants)
This is the most important thing to know about NA EJ25 engines: head gasket failures are essentially a guaranteed service item on high-mileage SOHC EJ25 engines (EJ251 / EJ253):
The issue: Open-deck block design combined with the head gasket material used results in eventual external coolant leaks or oil-coolant cross-contamination
Service interval: Typically occurs at 100,000-150,000 miles
Symptoms: External coolant weeping (smell of coolant, slow loss), or in worse cases coolant in oil (milky oil)
Cost: $1,500-3,000 for proper head gasket service including replacement head gaskets, machined head surfaces, and updated fasteners
Critical: When buying a used NA EJ25 engine, head gasket service history is essential information
This is widely documented as a known Subaru service item, NOT a defect. Subaru even acknowledged the issue with extended warranties on some affected models. Properly serviced (with updated multi-layer steel head gaskets), the EJ25 NA can run reliably for another 100,000+ miles.
Turbo Variants (EJ255 / EJ257) generally have fewer head gasket issues due to the higher-quality components used in performance applications, but face other concerns:
Ringland failures: Particularly at high boost on stock internals (most common reason for EJ257 rebuilds)
Rod bearing wear: At high RPM and high boost
Carbon buildup on valves: From direct injection variants
Why Choose a Used Subaru EJ25 Engine?
Cost savings vs reman (variant-dependent, $4,500 used vs $4,500-7,500 reman plus core for turbo variants)
Variant matching , we identify EJ251 vs EJ253 vs EJ255 vs EJ257 vs Cosworth EJ257
Direct OEM fit for Impreza, Forester, Outback, Legacy, WRX, WRX STI, Baja
Strong aftermarket , the EJ family has one of the largest aftermarkets of any Japanese engine
Performance potential , especially EJ257 / Cosworth EJ257 for serious builds
Symmetrical AWD compatibility , direct mate for Subaru transmissions
Here, you’ll find this Subaru EJ25 engine for sale at the most reasonable price possible, with variant identification, donor vehicle confirmation, head gasket condition assessment (critical EJ25 service area), turbocharger inspection (turbo variants), and complete testing.
| engine-family | Subaru EJ-series flat-4 (horizontally opposed boxer) |
|---|---|
| variants | Cosworth EJ257, EJ251, EJ253 (NA SOHC), EJ255, EJ257 (turbo DOHC) |
| manufacturer | Subaru Corporation (Fuji Heavy Industries) |
| hp-range | 165 HP (EJ251) to 305 HP (EJ257 stock), up to 500+ HP (Cosworth) |
| torque-range | 166 lb-ft (NA) to 290 lb-ft (EJ257) |
| displacement | 2.5L (2, 457 cc) |
| bore-x-stroke | 99.5 mm x 79.0 mm |
| configuration | Flat-4 (horizontally opposed boxer, NOT inline) |
| block-material | Open-deck aluminum |
| head-material | Aluminum |
| aspiration | NA (EJ251/EJ253) or Turbocharged (EJ255/EJ257) |
| fuel-type | Regular 87 (NA) or Premium 91-93 (turbo) |
| valvetrain | SOHC per bank (NA) or DOHC per bank (turbo, with AVCS) |
| production-years | 1995-2021 |
| direct-fit | Baja, Forester, Forester XT, Legacy, Legacy GT, Outback, Subaru Impreza, WRX, WRX STI |
| replaced-by | 2011+) and FA20DIT/FA24F (turbo), FB25 (NA |
| price | $4, 500.00 |
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