🏷️ Basic Information

Make:

Subaru

Model:

Legacy

Year:

2004

Chassis Code:

BP (Wagon), BL (Sedan)

👋 Introduction

Market Niche:

The 2004 Subaru Legacy, part of the third generation (BP/BL), continued Subaru's tradition of offering all-wheel-drive as standard, appealing to buyers seeking traction in varied weather conditions and a reliable, practical vehicle with a touch of sporty driving dynamics, especially in the GT models.

Key Competitors:

Competed against models like the Honda Accord, Toyota Camry, Nissan Altima, Mazda6, and Ford Fusion, often differentiating itself with standard AWD and boxer engine configurations.

Vehicle Highlights:

Standard Symmetrical All-Wheel Drive, available turbocharged engines (2.5 GT), comfortable and spacious interior, robust build quality, flat-four boxer engine design for a lower center of gravity.

📋 Manual Details

Model Variants Covered:

All 2004 Subaru Legacy trims, including naturally aspirated and turbocharged (GT) models. Covers both sedan and wagon body styles.

Estimated Page Count:

Approx. 2000-3000 pages (typical for comprehensive factory service manuals)

Manual Type:

Factory Service Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Engine Management:

ECU diagnostics, fuel injection, ignition system, emissions control (including EGR, PCV, EVAP).

Powertrain:

Detailed coverage of EJ253 (2.5L SOHC NA), EJ255 (2.5L DOHC Turbocharged), and EZ30D (3.0L H6 DOHC NA) engines. Includes engine mechanical, cooling, lubrication, and exhaust systems.

Transmission Drivetrain:

Manual and automatic transmissions (5MT, 4EAT, 5EAT). All-Wheel Drive (AWD) system, differential (front and rear), transfer case, driveshafts, and CV joints.

Suspension Steering:

Front and rear suspension (struts, control arms, bushings), steering system (rack and pinion, power steering pump, steering column).

Brakes:

Hydraulic brake system, ABS, EBD, brake fluid specifications, rotors, calipers, brake lines, parking brake.

Electrical Electronics:

Wiring diagrams, fuse box locations, relays, starter, alternator, battery, lighting systems, power windows, door locks, mirrors, wipers, horn.

HVAC:

Air conditioning system, heater core, blower motor, climate control panel, refrigerant specifications and procedures.

Body Chassis:

Body panel removal and installation, doors, hood, trunk/liftgate, bumpers, glass replacement, interior trim, chassis components.

Maintenance Procedures:

Scheduled maintenance, oil changes, filter replacements (oil, air, fuel, cabin), spark plug replacement, coolant flush, brake fluid flush.

Diagnostic Procedures:

Troubleshooting guides, diagnostic trouble codes (DTCs), symptom-based diagnostics, wiring harness testing, sensor testing.

Repair Procedures:

Engine overhaul, transmission removal and installation, clutch replacement, suspension component replacement, brake caliper overhaul, AC system service.

Installation Procedures:

Component replacement (alternator, starter, water pump, fuel pump), sensor installation, body part alignment.

Depth Of Coverage:

Comprehensive. Covers everything from basic fluid checks to complete engine and transmission rebuilds, including detailed torque specifications and component clearances.

📊 Manual Specifications

File Format Details:

PDF. Optimized for digital viewing and printing. High-resolution images and clear text.

Image Quality:

Excellent. Includes detailed diagrams, schematics, and high-quality photographs of components and procedures.

Binding Type:

Not Applicable (Digital PDF format)

Paper Type:

Not Applicable (Digital PDF format)

⚙️ Engine Specifications

Engine Options:

EJ253 (2.5L SOHC 16-valve Flat-4 NA), EJ255 (2.5L DOHC 16-valve Turbocharged Flat-4), EZ30D (3.0L DOHC 24-valve Flat-6 NA).

Horsepower Torque:

EJ253: ~165 hp @ 5600 rpm, ~166 lb-ft @ 4000 rpm. EJ255: ~250 hp @ 6000 rpm, ~250 lb-ft @ 3600 rpm. EZ30D: ~212 hp @ 6000 rpm, ~207 lb-ft @ 4200 rpm (specifications vary slightly by region).

Fuel Delivery:

Electronic Fuel Injection (EFI). Sequential multi-port fuel injection. Turbocharged models utilize an intercooler.

Engine Codes:

EJ253, EJ255, EZ30D

Cooling Type:

Liquid-cooled, pressurized system with thermostatically controlled fan.

Oil Type Capacity:

Recommended oil: SAE 5W-30 synthetic. Capacity: Approx. 4.5-5.0 quarts for 2.5L engines, 6.0 quarts for 3.0L H6. Always refer to manual for exact capacity and type.

🔧 Transmission

Transmission Options:

5-speed manual transmission (5MT), 4-speed automatic transmission (4EAT), 5-speed automatic transmission (5EAT - typically on GT models).

Transmission Variants:

5-speed automatic (5EAT) was an option on higher trims and GT models.

Drivetrain Features:

Symmetrical All-Wheel Drive (AWD) standard across all models. AWD system typically consists of a viscous coupling center differential (manual) or electronically controlled transfer clutch (automatic).

Transmission Fluid:

Manual: Subaru Extra-S Gear Oil (or equivalent API GL-5 75W-90). Automatic: Subaru ATF-HP (or equivalent Dexron III/Mercon type, check manual for exact spec).

📐 Dimensions

Length:

Sedan: Approx. 188.2 inches. Wagon: Approx. 189.0 inches.

Width:

Approx. 68.1 inches.

Height:

Sedan: Approx. 57.1 inches. Wagon: Approx. 57.9 inches.

Curb Weight:

Approx. 3200 - 3500 lbs (depending on engine and trim).

Trunk Volume:

Sedan: Approx. 14.7 cu ft. Wagon: Approx. 31.4 cu ft (seats up).

Wheelbase:

Approx. 104.0 inches.

🛡️ Safety Features

NHTSA Ratings:

Frontal crash test: 5-star driver/passenger. Side impact test: 4-star front/rear passenger. Rollover rating: 4-star. (Ratings may vary slightly by specific test year).

Active Safety Systems:

Standard All-Wheel Drive, Anti-lock Braking System (ABS), Electronic Brake-force Distribution (EBD).

Passive Safety Features:

Front airbags, front side-impact airbags, front and rear head curtain airbags (on some trims/options), pretensioner seatbelts, LATCH child seat anchors.

Standard Tire Size:

Typically P205/55R16 or P215/45R17 for GT models. Always consult manual for exact specifications.

Bolt Pattern:

5x100mm

💡 Technology Features

Infotainment Features:

Standard AM/FM/CD player. Optional premium audio systems with subwoofer. Auxiliary input may be available on later models or as an aftermarket addition.

Driver Assistance Systems:

Cruise control is standard. Limited advanced driver-assistance systems for this era; focus is on core mechanicals and safety.

Connectivity Options:

Limited by modern standards. Primarily basic audio connectivity. Bluetooth and navigation were rare or aftermarket options for this model year.

🔧 Maintenance

Oil Change Interval:

Recommended every 3,750 miles or 6 months, or 7,500 miles/12 months with synthetic oil and filter, under normal driving conditions. Severe conditions may require shorter intervals. (Always consult owner's manual).

Major Service Items:

Timing belt (if applicable to specific engine variant, though most 2004 EJ/EZ engines use a timing chain or a belt that requires replacement around 100,000 miles). Spark plugs: ~60,000 miles. Coolant: ~30,000 miles or every 2 years. Transmission fluid: ~30,000 miles (automatic), ~60,000 miles (manual).

Coolant Type:

Subaru Super Coolant (blue) or equivalent silicate-free, long-life antifreeze. Mixture: 50/50 with distilled water.

Brake Fluid:

DOT 3 or DOT 4 brake fluid.

Common Issues:

Head gasket leaks (more common on older EJ engines but can occur), catalytic converter failure, rear differential noise, automatic transmission shifting issues, wheel bearing wear, A/C system leaks. Turbocharged models may require more diligent maintenance to prevent issues like turbo oil feed line clogging.

Oil Filter Example:

Subaru OEM 15208AA031 or equivalent like FRAM PH7317, Wix 57045.

Air Filter Example:

Subaru OEM 16546AA050 or equivalent like Wix 49159.

📚 Vehicle History

Subaru Legacy Heritage:

The Subaru Legacy has been a cornerstone of the brand since its introduction in 1989, known for its AWD system, boxer engines, and reputation for reliability and driver engagement. It replaced the Subaru Leone.

Third Generation Evolution:

The 2004 model year falls within the third generation (BP/BL, 2003-2009). This generation introduced a more modern design, improved chassis dynamics, and the introduction of the potent 3.0L H6 EZ30D engine and the turbocharged 2.5 GT variant.

Manufacturing Location:

Primary manufacturing location: Gunma Prefecture, Japan.

🏆 Awards & Recognition

Notable Awards:

While specific awards for the 2004 model might be scarce, Subaru Legacy vehicles generally received praise for their all-wheel-drive capabilities and practicality. The brand as a whole has consistently ranked high in customer satisfaction and reliability surveys over the years.

Consumer Reports Rating:

Consumer Reports often rated Subaru vehicles favorably for their all-wheel drive and owner satisfaction. Reliability for the 2004 Legacy could be average to good, with some model-specific issues to be aware of as detailed in the manual.