Model Segment:
Executive Car / Mid-size Luxury Sedan
Brand Perception 1991:
Audi positioned as a premium European manufacturer, known for sophisticated engineering, Quattro all-wheel drive, and understated luxury.
Key Competitors:
BMW 5 Series, Mercedes-Benz E-Class, Volvo 240/740/940, Saab 9000.
Aerodynamics:
The C3 generation Audi 100 was renowned for its exceptionally low drag coefficient, contributing to fuel efficiency and reduced wind noise.
Quattro Availability:
Optional Quattro all-wheel drive system offered enhanced traction and stability, particularly in adverse weather conditions.
Build Quality:
Known for solid construction and high-quality interior materials characteristic of German automotive engineering.
Manual Coverage:
Comprehensive service, repair, and maintenance for the 1991 Audi 100.
Estimated Page Count:
Likely 800-1200 pages (typical for comprehensive factory-level manuals of this era)
Manual Type:
Workshop Service and Repair Manual
Format:
PDF (Portable Document Format)
Engine Systems:
Engine mechanical (assembly, disassembly, overhaul), fuel injection (Bosch KE-Jetronic), ignition, cooling, lubrication, exhaust.
Drivetrain Systems:
Manual and Automatic transmissions (gearbox overhaul, clutch, driveshafts, differential).
Suspension Steering:
Front and rear suspension components, steering system (rack and pinion, power steering).
Braking System:
Hydraulic brake system, ABS (Anti-lock Braking System) if equipped, parking brake, disc and drum brake servicing.
Electrical System:
Wiring diagrams, starting and charging system, lighting, instruments, comfort electronics, fuse and relay locations.
Body And Chassis:
Body panels, doors, glass, interior trim, body sealing, chassis lubrication, corrosion protection.
Preventative Maintenance:
Oil changes, filter replacements, fluid checks and top-ups, spark plug replacement, belt inspections, brake fluid flush.
Troubleshooting:
Diagnostic procedures for common drivability issues, electrical faults, and mechanical problems.
Component Repair:
Detailed step-by-step instructions for the repair or replacement of virtually all mechanical and electrical components.
Specifications And Tolerances:
Torque specifications for all fasteners, engine clearances, alignment specifications.
Diagnostic Procedures:
Includes diagnostic flowcharts and symptom-based troubleshooting guides.
Rebuild Procedures:
Detailed instructions for the complete overhaul of major components like engines and transmissions.
Wiring Diagrams:
Comprehensive electrical schematics for all vehicle systems.
Engine Code Examples:
Various, common ones include AAE, ABC, ABK for 2.0L and 2.3L variants.
Engine Displacement Common:
2.0L (1986cc) and 2.3L (2309cc) inline-5 cylinders.
Engine Configuration:
Inline 5-cylinder, SOHC (Single Overhead Camshaft) or DOHC (Double Overhead Camshaft) depending on variant.
Horsepower Range:
Approximately 100-140 hp depending on engine and specification.
Torque Range:
Approximately 125-165 lb-ft depending on engine and specification.
Fuel Delivery:
Bosch KE-Jetronic CIS-E (Continuous Injection System - Electronic) fuel injection.
Fuel Type:
Unleaded Gasoline (Octane rating typically 91 RON/87 AKI recommended)
Length Approx:
Approx. 4790 mm (188.6 in)
Width Approx:
Approx. 1770 mm (69.7 in)
Height Approx:
Approx. 1420 mm (55.9 in)
Wheelbase Approx:
Approx. 2700 mm (106.3 in)
Curb Weight Range:
Approx. 1300-1450 kg (2866-3197 lbs) depending on engine and drivetrain.
NHTSA Rating Era:
NHTSA ratings were less standardized in this era; focus was on passive safety features. Comparable vehicles from this period generally received fair to good ratings for their time.
ABS Availability:
Optional Anti-lock Braking System (ABS) available on some models.
Airbags:
Driver-side airbag typically standard or optional on higher trims for 1991 models.
Seatbelts:
Three-point inertia-reel seatbelts for all occupants.
Body Structure:
Designed with a reinforced passenger safety cell and energy-absorbing crumple zones.
Audio System:
Factory-installed AM/FM stereo cassette player, often with premium speaker options.
Climate Control:
Manual climate control standard; optional automatic climate control (often prone to sensor and vacuum line issues).
Cruise Control:
Optional cruise control system.
Original Connectivity:
Limited to antenna and radio signals; no modern connectivity features like Bluetooth or USB.
Oil Change Interval:
Typically every 5,000-7,500 miles or 6-12 months, depending on driving conditions and oil type used (refer to manual for exact spec).
Timing Belt Replacement:
Crucial for these inline-5 engines; typically recommended every 60,000-80,000 miles or 5-7 years. Failure can cause catastrophic engine damage.
Engine Oil Spec:
API SG or higher, SAE 5W-40 or 10W-40 depending on climate. Consult manual for precise viscosity and capacity (typically 4.5-5.0 liters).
Coolant Spec:
Ethylene glycol-based antifreeze, typically a 50/50 mix with distilled water. G11 specification (or equivalent blue/green coolant).
Transmission Fluid Manual:
API GL-4 or GL-5, SAE 75W-90 or 80W-90 gear oil. Capacity approx. 2.0-2.5 liters.
Transmission Fluid Automatic:
Dexron II or equivalent ATF. Capacity approx. 3.0-3.5 liters (pan fill). Check for specific ZF fluid compatibility if applicable.
Cooling System:
Plastic coolant expansion tank can become brittle and crack; radiator hoses can degrade.
Fuel System:
KE-Jetronic system requires precise adjustment; airflow meter potentiometers can wear, fuel distributors can leak.
Electrical:
Degrading wiring insulation (especially engine bay wiring harnesses), failing climate control units, and door lock actuators are common as the cars age.
Suspension:
Worn control arm bushings, ball joints, and tie rod ends due to age and mileage.
Audi Founding Principles:
Founded in 1910, Audi has a history of engineering innovation and technological advancement in the automotive industry.
C3 Generation Intro:
The C3 generation Audi 100 was first introduced in 1982 and represented a significant step forward in automotive design and technology, particularly with its aerodynamic styling and front-wheel drive platform.
Updates For 1991:
The 1991 model year typically represented the later stages of the C3 lifecycle, potentially with minor trim or option package updates, but retaining the core design and engineering.
Manufacturing Location:
Primarily manufactured in Germany.
Production Years C3:
1982-1991 (global production for the C3 generation).
Aerodynamic Design Award:
The C3 generation Audi 100 was frequently lauded for its pioneering aerodynamic design, setting new benchmarks for the industry.
European Car Of The Year Nominee:
While not winning in its debut year (1983), the C3 generation was a significant contender, reflecting its advanced engineering and design.
Reliability Reputation:
Generally considered a reliable car when properly maintained, though age-related issues are common in vehicles from this era.
