🏷️ Basic Information

Make:

Chevrolet

Model:

Impala

Year:

2004

Generation Code:

Epsilon II

Vin Prefix:

1G

👋 Introduction

Segment:

Full-size sedan, competing with Ford Crown Victoria, Toyota Avalon, Chrysler 300M.

Strengths:

Spacious interior, comfortable ride, strong V6 and V8 engine options for its class, good value proposition.

Platform:

GM Epsilon platform, shared with Opel Vectra, Saab 9-3.

Design:

Distinctive styling, often criticized for being somewhat bland by automotive critics but appreciated for its straightforward design by consumers.

📋 Manual Details

Primary Focus:

Service, Repair, Maintenance

Additional Focus:

Diagnostics, Troubleshooting, Wiring Diagrams

Estimated Pages:

Extensive (digital format, equivalent to over 2000 printed pages)

Type:

Official Service and Repair Manual Software

Language:

English

Format:

PDF Download (Digital Access)

📖 Manual Coverage

Powertrain:

Engine, Fuel System, Cooling System, Exhaust System, Drivetrain (Front-Wheel Drive), Transmission (Automatic)

Chassis:

Suspension (Front & Rear), Steering System, Brakes (Front & Rear, ABS)

Electrical:

Body Control Module (BCM), Powertrain Control Module (PCM), Lighting, Instrumentation, HVAC Controls, Audio System, Power Accessories, SRS (Airbag) System, Anti-theft System

Body:

Exterior Body Panels, Doors, Windows, Interior Trim, Seats, Convertible Top (if applicable)

Maintenance:

Oil Change, Filter Replacement, Fluid Checks & Top-offs, Spark Plug Replacement, Belt Inspection & Replacement, Tire Rotation

Repair:

Engine Component Replacement (e.g., alternator, starter, water pump), Brake Pad & Rotor Replacement, Suspension Component Replacement (e.g., struts, ball joints), HVAC System Repair, Electrical Component Diagnosis & Replacement, Drivetrain Component Service

Diagnostics:

Diagnostic Trouble Code (DTC) retrieval and interpretation, Component testing, Circuit diagnostics, Symptom-based troubleshooting

Suspension And Steering Repair:

Detailed procedures for replacement of struts, shocks, ball joints, tie rod ends, power steering pump, and steering rack.

Brake System Service:

Complete guide to brake pad and rotor replacement, caliper service, and brake bleeding for ABS-equipped vehicles.

Depth:

Comprehensive, from routine maintenance to major component overhaul and electrical system diagnostics.

Special Tools:

Identification of specialized tools required for specific repairs.

Wiring Diagrams:

Detailed electrical wiring diagrams for all major systems.

📊 Manual Specifications

Format Details:

Searchable PDF, printable pages, accessible via web browser on PC, laptop, smartphone, tablet.

Quality:

High-resolution, professional scans of original factory documentation.

Binding:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

⚙️ Engine Specifications

Engine Type:

3.8L V6 OHV (L36)

Displacement:

3791 cc

Bore X Stroke:

96.5 mm x 86.7 mm

Compression Ratio:

9.5:1

Horsepower:

200 hp @ 5200 rpm

Torque:

230 lb-ft @ 3600 rpm

Fuel System:

Sequential Electronic Fuel Injection (SEFI)

Engine Type:

3.4L V6 OHV (L32)

Displacement:

3350 cc

Horsepower:

180 hp @ 5200 rpm

Torque:

205 lb-ft @ 4000 rpm

Acceleration 0 60:

Approx. 8.5-9.5 seconds (3.8L V6)

Fuel Type:

Unleaded Gasoline

Recommended Octane:

87 (Octane Rating)

🔧 Transmission

Transmission Type:

4-speed Automatic (4T65-E)

Optional Transmission:

N/A for 2004 model year

Transmission Features:

Lock-up torque converter, electronic controls, overdrive.

📐 Dimensions

Length:

197.9 inches

Width:

72.1 inches

Height:

57.4 inches

Wheelbase:

110.5 inches

Curb Weight Min:

3530 lbs (3.4L V6)

Curb Weight Max:

3640 lbs (3.8L V6)

🛡️ Safety Features

NHTSA Front Impact:

5 Stars (Driver), 4 Stars (Passenger)

IIHS Side Impact:

Good

ABS:

Standard (Anti-lock Braking System)

Airbags:

Standard front airbags; Optional side-impact airbags.

Seatbelts:

Three-point seatbelts with pretensioners.

💡 Technology Features

Audio System:

Available premium Bose audio system, CD player, AM/FM radio.

Cruise Control:

Standard on most trims

Features:

Basic connectivity features of the era; no Bluetooth or advanced smartphone integration.

🔧 Maintenance

Oil Change Interval:

Every 7,500 miles or 6 months (using synthetic blend oil, refer to manual for specific recommendations).

Tire Rotation Interval:

Every 7,500 miles

Spark Plug Replacement:

Typically 100,000 miles for Ecotec 3.4L V6 (check manual for specific engine).

Engine Oil Type:

SAE 5W-30 (API Certified, GM spec GM6094M)

Coolant Type:

Dex-Cool Extended Life Antifreeze/Coolant (GM Part No. 12346290 or equivalent)

Transmission Fluid Type:

Dexron VI Automatic Transmission Fluid (GM Part No. 88863400 or equivalent)

Brake Fluid Type:

DOT 3

Common Problems:

Intake manifold gasket leaks, rear main seal leaks (3.8L V6), power steering pump leaks, HVAC blend door actuator failure, coolant leaks from Dex-Cool issues, some electronic module failures.

Troubleshooting Tips:

The manual provides detailed diagnostic procedures for these and other common issues.

📚 Vehicle History

Chevrolet Legacy:

Chevrolet, founded in 1911, has a long history of producing reliable and accessible vehicles for the American market.

Impala Lineage:

The Impala nameplate has a storied history in Chevrolet's lineup, evolving from a premium full-size car in the 1960s to a more mainstream offering in later generations.

Manufacturing Location:

Oshawa, Ontario, Canada

Production Period:

This generation of Impala (2000-2005) represented a significant shift from its rear-wheel-drive predecessors to a front-wheel-drive platform.

🏆 Awards & Recognition

Awards List:

While not a recipient of major "Car of the Year" awards, the Impala was a consistent volume seller and often praised for its comfortable ride and value.