🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Year:

2005

Product Name:

Subaru Impreza WRX STI 2005 Workshop Repair Service Manual PDF Download

👋 Introduction

Segment:

Performance Compact Sedan/Wagon

Reputation:

Legendary rally-bred performance car, known for its all-wheel-drive system and turbocharged engine.

Direct Competitors:

Mitsubishi Lancer Evolution, Ford Focus RS (later models), Volkswagen Golf GTI (performance variants).

Drivetrain:

Symmetrical All-Wheel Drive (SAWD) system with Driver Controlled Center Differential (DCCD).

Engine Technology:

Horizontally opposed (Boxer) turbocharged engine for low center of gravity and balanced performance.

Suspension Setup:

Performance-tuned suspension, often with Bilstein or similar dampers and stiffer springs, specifically for the STI variant.

Braking System:

Upgraded Brembo braking system for superior stopping power.

Interior Features:

Sport seats (Recaro optional/standard on some trims), STI-specific instrumentation, DCCD control.

📋 Manual Details

Engines Covered:

All engine variants for the 2005 Impreza WRX STI

Trim Levels Covered:

All trim levels for the 2005 Impreza WRX STI

Regional Variants:

Likely covers major global markets, including North America, Europe, and Japan, based on STI prevalence.

Estimated Page Count:

Approximately 2000-3000 pages (typical for comprehensive workshop manuals of this era)

Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Engine assembly, disassembly, cylinder head, pistons, crankshaft, timing belt/chain, lubrication system, cooling system.

Engine Management:

ECU, sensors (MAP, MAF, O2, crank, cam), fuel injection, ignition system, emissions control.

Transmission:

Manual transmission (TY757), clutch, gearbox overhaul, driveline, center differential, rear differential.

Suspension:

Front suspension (struts, control arms, sway bar), rear suspension (multi-link, trailing links, sway bar), alignment specifications.

Brakes:

Front and rear brake systems (calipers, rotors, pads, lines), ABS system, parking brake.

Steering:

Power steering system, steering rack, column, wheel alignment.

Electrical:

Battery, charging system, starter, lighting, wipers, horn, power windows, central locking, dashboard instruments, fuse box diagrams, wiring diagrams.

Bodywork:

Body shell, exterior panels, doors, hood, trunk, bumpers, glass, interior trim, noise insulation.

HVAC:

Air conditioning system, heater, ventilation, climate control.

Maintenance:

Oil changes, filter replacements, spark plug replacement, fluid checks and changes, tire rotation.

Troubleshooting:

Diagnostic procedures for common faults, error code interpretation, symptom-based troubleshooting.

Repair:

Step-by-step repair instructions for all major vehicle systems, including engine rebuild, transmission overhaul, suspension component replacement.

Overhaul:

Detailed procedures for complete disassembly and reassembly of major components like engines and transmissions.

Diagnostics:

Procedures for using diagnostic tools, reading sensor data, identifying faults.

Specifications Settings:

Torque specifications, alignment settings, valve clearances, fuel pressures.

Depth:

Comprehensive, covering basic maintenance to full engine and transmission rebuilds, including electrical diagnostics and body repairs.

📊 Manual Specifications

Format:

PDF (Portable Document Format)

Searchability:

Text-searchable PDF for easy information retrieval.

Printability:

Printable pages for workshop use.

Quality:

High-resolution scans ensuring clarity of diagrams and text.

Type:

N/A (Digital PDF download)

Type:

N/A (Digital PDF download)

⚙️ Engine Specifications

Engine Code:

EJ257

Configuration:

2.5-liter (2457 cc) turbocharged and intercooled horizontally opposed (Boxer) 4-cylinder.

Bore X Stroke:

99.5 mm x 79.0 mm

Compression Ratio:

8.2:1

Horsepower:

300 hp @ 6000 rpm (approx.)

Torque:

300 lb-ft @ 4000 rpm (approx.)

Fuel Delivery:

Sequential multi-port fuel injection (MPI)

Fuel Type:

Premium Unleaded Gasoline (91 octane or higher recommended)

Cooling Type:

Liquid-cooled, pressurized

Oil Capacity:

Approximately 5.8 US quarts (5.5 liters) with filter change

Type:

IHI VF39 (or similar, depending on market/spec)

🔧 Transmission

Type:

6-speed manual transmission

Transmission Code:

TY757

Type:

N/A (STI models exclusively featured the manual transmission)

Dccd:

Driver Controlled Center Differential (DCCD) for manual adjustment of front/rear torque bias.

Differentials:

Front: Helical limited-slip differential (LSD); Rear: Viscous coupling limited-slip differential (LSD).

Gearbox Oil:

Refer to manual for specific Subaru specification (e.g., 75W-90 GL-5).

Front Differential Oil:

Refer to manual for specific Subaru specification (e.g., 75W-90 GL-5).

Rear Differential Oil:

Refer to manual for specific Subaru specification (e.g., 75W-90 GL-5).

📐 Dimensions

Length:

Approx. 175.1 inches (4448 mm)

Width:

Approx. 70.1 inches (1780 mm)

Height:

Approx. 56.1 inches (1425 mm)

Wheelbase:

Approx. 104.3 inches (2650 mm)

Curb Weight:

Approx. 3263 lbs (1480 kg)

Gross Vehicle Weight Rating:

Refer to vehicle placard (typically around 4000 lbs).

Standard Wheel Size:

17x8.0 inches

Optional Wheel Size:

18x8.5 inches (common STI upgrade)

Standard Tire Size:

225/45R17

Wheel Bolt Pattern:

5x114.3 mm (5x4.5 inches)

Lug Nut Torque:

73.8 lb-ft (100 Nm)

🛡️ Safety Features

NHTSA Front Impact:

5-star (for driver and passenger, in applicable tests for the era)

IIHS Side Impact:

Good (likely, based on structural design for performance vehicles)

ABS:

Anti-lock Braking System (4-wheel, performance tuned)

Ebdc:

Electronic Brake-force Distribution (often integrated with ABS)

AWD:

Symmetrical All-Wheel Drive (SAWD) enhances traction and stability.

Airbags:

Front dual-stage airbags for driver and passenger, side-impact airbags (may be standard or optional depending on trim).

Seatbelts:

Three-point seatbelts with pretensioners and load limiters.

Structure:

Reinforced chassis and safety cage design for occupant protection.

💡 Technology Features

Head Unit:

Factory radio with CD player, likely with AM/FM tuner. Basic display for time and station.

Speakers:

Standard speaker configuration, potential for upgraded sound systems depending on trim.

Traction Control:

Advanced traction control system integrated with the AWD and ABS systems.

Stability Control:

Electronic Stability Control (VDC - Vehicle Dynamics Control) is often standard or available.

Connectivity Features:

Limited by era; typically includes analog audio inputs. No Bluetooth or USB connectivity.

Gauge Cluster:

STI-specific gauges including a prominent tachometer, speedometer, boost gauge (integrated into gauges or separate), fuel, and temperature. Warning lights for all major systems.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles or 6 months, especially under severe driving conditions. High-performance engines benefit from more frequent changes.

Air Filter Replacement:

Every 15,000-30,000 miles or as needed based on conditions.

Spark Plug Replacement:

Typically every 60,000 miles for iridium plugs, check manual for specific recommendations.

Timing Belt Replacement:

Crucial! Typically every 60,000-105,000 miles or 7-10 years, depending on original equipment and manufacturer recommendation for the EJ257 engine. Failure can cause catastrophic engine damage.

Coolant Flush:

Every 30,000-60,000 miles or 2-4 years.

Engine Oil:

Refer to manual: Commonly 5W-30 or 10W-30 synthetic oil meeting API SG/SH/SJ/SL/SM classification. High-performance oils recommended.

Coolant:

Subaru Blue Coolant (or equivalent silicate-free Asian vehicle coolant), typically a 50/50 mix with distilled water.

Brake Fluid:

DOT 3 or DOT 4 synthetic brake fluid.

Headgaskets:

While less common on EJ257 compared to earlier EJ25s, head gasket leaks can still occur, especially with modified engines or extreme heat cycling.

Ringland Failure:

A known vulnerability on the EJ257 engine, particularly when subjected to aggressive tuning or sustained high boost without proper fuel and management. The manual will detail piston inspection and ring gap specifications.

Clutch Wear:

Performance driving can lead to accelerated clutch wear. Manual provides clutch inspection and replacement procedures.

Oil Consumption:

Some EJ257 engines may exhibit higher oil consumption than other engines. Regular checks are essential.

Turbocharger Wear:

Turbocharger seals and bearings can wear over time, especially with inadequate warm-up/cool-down procedures. Manual covers turbo inspection and replacement.

📚 Vehicle History

Rally Roots:

Subaru's extensive motorsports heritage, particularly in the World Rally Championship (WRC), directly influences the Impreza WRX STI's development.

Third Generation:

This 2005 model is part of the second generation (GD/GG) Impreza, often referred to as the 'Bugeye' (pre-facelift) or 'Blobeye' (facelift, including 2005) depending on specific styling cues. The STI variant represents the pinnacle of performance within this generation.

Gc8 To Gd:

Transition from the classic GC8 chassis to the GD chassis brought significant chassis stiffening, improved aerodynamics, and refined mechanicals.

Manufacturing Location:

Japan

Production Years:

2000-2007 (for the second generation GD/GG chassis).

🏆 Awards & Recognition

Car And Driver 10Best:

The Subaru Impreza WRX STI (across generations) has frequently been recognized on prestigious automotive lists, including Car and Driver's 10Best. While specific mentions for the 2005 model may vary, its performance pedigree is undeniable.

Motorsport Accolades:

Continuous success in WRC and other motorsport disciplines validates the engineering and performance of the STI line.

Performance Reviews:

Consistently lauded by automotive journalists for its handling, acceleration, and driver engagement.