🏷️ Basic Information

Make:

Buick

Model:

Century

Year:

1991

Platform:

GM W-body

👋 Introduction

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.

Competitors:

Competed against vehicles like the Ford Taurus, Chevrolet Lumina, Dodge Spirit, and Honda Accord.

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

Primary Coverage:

Service and Repair

Secondary Coverage:

Maintenance, Diagnostics, Troubleshooting

Estimated Pages:

Varies by engine and options (typically 1000+ pages for full factory manual equivalent)

Type:

Service and Repair Manual Software

Source:

Licensed information derived from Original Equipment (OE) manufacturer materials.

Language:

English

Format:

PDF Download (Digital Access)

📖 Manual Coverage

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.

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.

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

Quality:

High-resolution, searchable PDF with clear diagrams and illustrations.

Searchability:

Fully searchable text for quick access to specific topics and procedures.

Printable:

Printable pages for easy workshop use.

Binding:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

⚙️ Engine Specifications

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

Horsepower Range:

110-160 HP

Torque Range:

145-185 lb-ft

Fuel Delivery:

Port Fuel Injection (PFI)

Ignition System:

Distributorless Ignition System (DIS) or Distributor Ignition System (DIS) depending on engine variant.

Engine Code L4:

2.5L Tech IV (LL8)

Engine Code V6 3300:

3.3L 3300 (LG7)

Engine Code V6 3100:

3.1L 3100 (LHO)

🔧 Transmission

Transmission Option 1:

3-speed Automatic (THM3T40)

Transmission Option 2:

4-speed Automatic (4T60-E)

Lock-Up Torque Converter:

Present on automatic transmissions for improved fuel efficiency.

📐 Dimensions

Wheelbase:

107.0 inches

Length:

191.5 inches

Width:

68.3 inches

Height:

54.2 inches

Curb Weight Approx:

3000-3300 lbs (depending on engine and trim)

🛡️ Safety Features

NHTSA Frontal Impact Driver:

Not explicitly rated for this year by modern standards, but early W-body designs were considered safe for their era.

ABS:

Optional Anti-lock Braking System (ABS) on some models.

Airbags:

Driver-side airbag standard on most models for 1991.

Seatbelts:

Front 3-point seatbelts, rear lap and shoulder belts.

💡 Technology Features

Audio System:

AM/FM stereo radio, optional cassette player, optional CD player. Basic speaker configurations.

Cruise Control:

Optional on most models.

Connectivity Features:

None by modern standards; primarily mechanical and basic electrical systems.

🔧 Maintenance

Oil Change:

Every 3,000-5,000 miles or 3-6 months (depending on oil type and driving conditions).

Transmission Fluid:

Inspect every 15,000 miles, change every 30,000-60,000 miles (refer to manual for specific service).

Spark Plugs:

Replace every 30,000-60,000 miles depending on plug type (e.g., platinum plugs offer longer life).

Engine Oil:

API Service SG or SH, SAE 5W-30 or 10W-30 (refer to owner's manual for climate-specific recommendations).

Transmission Fluid:

Dexron-II (or equivalent) Automatic Transmission Fluid (ATF).

Coolant:

GM Type 1 Coolant (or equivalent 50/50 mix of ethylene glycol and distilled water).

Common Problems Engine:

Intake manifold gasket leaks (especially on 3.1L and 3.3L V6 engines), distributor hub wear, oil leaks from valve cover gaskets and oil pan gaskets.

Common Problems Transmission:

Torque converter shudder, internal seal wear leading to slippage, issues with shift solenoids (4T60-E).

Common Problems Electrical:

Faulty power window motors, headlight switch issues, alternator failures, instrument cluster illumination problems.

Common Problems Suspension:

Worn ball joints, tie rod ends, and strut mounts; sagging springs.

📚 Vehicle History

Buick Legacy:

Buick has a long history of producing comfortable, well-appointed, and reliable vehicles for the American market, often appealing to a mature demographic seeking value and refinement.

Century Evolution:

The 1991 Century was part of the second generation of the W-body platform, which debuted in 1988. This generation saw updates in styling, powertrain, and interior amenities, moving away from the older front-wheel-drive A-body platform.

Production Location:

Assembled in North America (e.g., Fairfax, Kansas; Oshawa, Ontario).

🏆 Awards & Recognition

Industry Recognition:

While specific awards for the 1991 model are not prominently documented, the Buick Century was consistently a strong seller in its segment, indicating market acceptance for its blend of comfort and value.