The 1991 Buick Century, built on the GM W-body platform, was a popular mid-size sedan and coupe recognized for its comfortable ride, spacious interior, and practical design. Positioned as a reliable family car, it offered a range of gasoline engines, including the 2.5L L4 and 3.3L V6, providing a balance of performance and efficiency for its era. Its competitive standing against models like the Ford Taurus and Honda Accord highlights its market appeal, emphasizing value and refinement as core attributes, characteristic of Buick's established brand heritage. This comprehensive service and repair manual provides detailed information for the 1991 Buick Century, covering all essential systems from engine diagnostics and maintenance to transmission overhaul, brakes, steering, suspension, and electrical systems. It includes step-by-step repair procedures, troubleshooting guides, and technical specifications, such as torque values and fluid requirements. The manual is designed to assist owners, mechanics, and technicians in effectively maintaining, diagnosing, and repairing the vehicle, ensuring optimal performance and longevity. 🏷️ Basic Information Identification Make: Buick Model: Century Year: 1991 Codes Platform: GM W-body 👋 Introduction Market Position Positioning: The 1991 Buick Century was a popular mid-size sedan and coupe in the American market, positioned as a comfortable and reliable family car with a focus on value and practicality. Competitive Analysis Competitors: Competed against vehicles like the Ford Taurus, Chevrolet Lumina, Dodge Spirit, and Honda Accord. Key Features Features: Known for its comfortable ride, spacious interior, and a range of available engine options. The W-body platform provided a solid foundation for handling and passenger comfort. Ui Design: User-friendly interface for easy navigation and information retrieval, designed for both novice and experienced mechanics. 📋 Manual Details Coverage Areas Primary Coverage: Service and Repair Secondary Coverage: Maintenance, Diagnostics, Troubleshooting Page Count Estimated Pages: Varies by engine and options (typically 1000+ pages for full factory manual equivalent) Manual Type Type: Service and Repair Manual Software Source: Licensed information derived from Original Equipment (OE) manufacturer materials. Language Language: English Format Format: PDF Download (Digital Access) 📖 Manual Coverage Systems Covered Engine: All gasoline engines, including components like ignition, fuel, cooling, lubrication, and emission control systems. Transmission: Automatic transmission service, overhaul, and diagnosis. Brakes: Hydraulic brake systems (front disc, rear drum), parking brake, ABS (if equipped). Steering: Power steering system, steering column, and linkages. Suspension: Front and rear suspension components, alignment specifications. Electrical: 12-volt electrical system, battery, charging system, starting system, lighting, instrument panel, power accessories, wiring diagrams. HVAC: Heating, Ventilation, and Air Conditioning (HVAC) system service and repair. Body: Body and chassis repair, interior and exterior trim, doors, glass, and weatherstripping. Fuel System: Fuel pump, fuel filter, fuel injectors, fuel pressure regulator, and fuel tank service. Cooling System: Radiator, water pump, thermostat, hoses, and heater core replacement and service. Procedures Included Maintenance: Scheduled maintenance, oil changes, fluid checks and changes, filter replacements, spark plug replacement, belt inspection and replacement. Repair: Detailed step-by-step repair procedures for all major vehicle systems, including component removal, installation, and adjustment. Diagnostics: Troubleshooting guides and diagnostic charts for common and uncommon issues, diagnostic trouble codes (DTCs) for OBD-I systems. Specifications: Torque specifications, clearances, fluid capacities, diagnostic parameters, and alignment data. Timing Belt Or Chain: Procedures for timing belt replacement (if applicable to specific engine) or timing chain inspection and replacement. Exhaust System: Diagnosis and repair of exhaust leaks, muffler and catalytic converter replacement. Air Conditioning Service: Refrigerant handling, component replacement (compressor, condenser, evaporator), leak detection, and evacuation/recharging. Technical Depth Depth: Comprehensive, factory-derived information suitable for professional technicians and advanced DIY enthusiasts. Covers everything from basic tune-ups to complete engine and transmission overhauls. Engine Rebuild: Includes detailed instructions for engine disassembly, inspection, cleaning, machining, and reassembly, with precise tolerances and specifications. Electrical Diagnostics: Extensive use of wiring diagrams, component testing procedures, and diagnostic flowcharts for pinpointing electrical faults. 📊 Manual Specifications File Format Quality: High-resolution, searchable PDF with clear diagrams and illustrations. Searchability: Fully searchable text for quick access to specific topics and procedures. Print Quality Printable: Printable pages for easy workshop use. Binding Type Binding: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Option 1: 2.5L L4 (Iron Duke), 110 HP @ 4800 RPM, 145 lb-ft @ 2400 RPM Engine Option 2: 3.3L V6 (3300), 160 HP @ 4800 RPM, 185 lb-ft @ 3200 RPM Engine Option 3: 3.1L V6 (3100), 140 HP @ 4800 RPM, 170 lb-ft @ 3200 RPM Performance Horsepower Range: 110-160 HP Torque Range: 145-185 lb-ft Fuel System Fuel Delivery: Port Fuel Injection (PFI) Ignition System: Distributorless Ignition System (DIS) or Distributor Ignition System (DIS) depending on engine variant. Engine Option 1 Engine Code L4: 2.5L Tech IV (LL8) Engine Option 2 Engine Code V6 3300: 3.3L 3300 (LG7) Engine Option 3 Engine Code V6 3100: 3.1L 3100 (LHO) 🔧 Transmission Standard Transmission Option 1: 3-speed Automatic (THM3T40) Optional Transmission...