🏷️ Basic Information

Make:

Audi

Model:

90

Year:

1990

Chassis Code:

Type 85 (B3)

👋 Introduction

Market Position:

The 1990 Audi 90 represented Audi's premium compact executive sedan offering, competing against established players like the BMW 3 Series and Mercedes-Benz 190E. It was positioned as a sophisticated, technologically advanced, and performance-oriented vehicle with a strong emphasis on its Quattro all-wheel-drive system.

Competitive Analysis:

Key competitors included the BMW 325i (E30), Mercedes-Benz 190E 2.3-16, Acura Legend, and Volvo 240. The Audi 90 differentiated itself with its unique 5-cylinder engine, advanced Quattro system (optional but highly sought after), and a focus on aerodynamic styling.

Key Features:

5-cylinder engine, Quattro AWD, advanced aerodynamics, comfortable and well-appointed interior, Bosch Motronic engine management, excellent build quality, and a focus on driver engagement.

📋 Manual Details

Engine Coverage:

2.3L 5-Cylinder (NG engine code)

Transmission Coverage:

5-speed Manual, 4-speed Automatic (013, 014)

Drivetrain Coverage:

Front-Wheel Drive (FWD), Quattro All-Wheel Drive (AWD)

System Coverage:

Engine Mechanical, Engine Control System, Fuel System, Ignition System, Exhaust System, Cooling System, Lubrication System, Clutch, Transmission, Drivetrain Components, Suspension, Steering, Brakes (ABS), Body and Chassis, Electrical System, HVAC, Interior Components, Exterior Trim, Maintenance and Lubrication, Troubleshooting, Specifications.

Page Count:

Approximately 600-700 pages (estimated for a comprehensive manual)

Manual Type:

Factory Authorized Repair Manual

Language:

English

Format:

Printed Book

📖 Manual Coverage

Engine Mechanical:

Detailed overhaul procedures for the 2.3L 5-cylinder engine, including cylinder head, block, pistons, crankshaft, camshafts, valve train, timing belt replacement (critical procedure), seals, and gaskets.

Engine Management:

In-depth coverage of the Bosch Motronic engine control system, including sensor identification, function, testing, diagnostic trouble codes (DTCs), fuel injection system, ignition timing, idle control, and emission control systems.

Suspension Steering:

Front and rear suspension component identification, removal, installation, alignment specifications, shock absorber replacement, steering rack overhaul, power steering system service.

Brakes:

Front and rear brake system diagnosis and repair, including disc brake pad and rotor replacement, caliper service, brake fluid bleeding, ABS system components identification and troubleshooting.

Electrical:

Comprehensive wiring diagrams for all electrical systems, including lighting, starting, charging, ignition, fuel injection, instrument cluster, power windows, power locks, HVAC controls, and optional equipment. Fuse and relay identification and testing.

Maintenance:

Scheduled maintenance intervals, oil and filter changes, coolant flushes, spark plug replacement, air filter replacement, drive belt inspection and replacement, brake fluid service, power steering fluid service.

Troubleshooting:

Diagnostic flowcharts and symptom-based troubleshooting guides for common issues related to engine performance, starting, electrical systems, and more.

Repair Overhaul:

Detailed step-by-step procedures for major component repairs, including engine rebuilds, transmission overhaul, suspension component replacement, brake system overhauls, and electrical component diagnostics and replacement.

Special Tools:

Identification and usage of specialized tools required for specific repair procedures, such as timing belt tools, engine timing tools, and diagnostic equipment.

Technical Depth:

Comprehensive; covers from routine maintenance to complete engine and transmission rebuilds, including detailed diagnostic procedures and specifications.

📊 Manual Specifications

File Format:

Not applicable for printed book

Print Quality:

High-quality paper stock, clear text and diagrams.

Binding Type:

Sturdy perfect binding or spiral binding for durability in a workshop environment.

Paper Type:

Durable, possibly coated paper to resist grease and oil.

⚙️ Engine Specifications

Engine Type:

Naturally Aspirated Inline 5-Cylinder

Engine Code:

NG

Displacement:

2309 cc (2.3 Liters)

Bore X Stroke:

76.5 mm x 102.0 mm

Compression Ratio:

10.3:1

Horsepower:

130 hp @ 5500 rpm (approx.)

Torque:

145 lb-ft @ 3200 rpm (approx.)

Fuel Delivery:

Bosch Motronic Electronic Fuel Injection (EFI)

Fuel Type:

Unleaded Gasoline (91 Octane Recommended)

Ignition Type:

Electronic Ignition with Knock Sensor

Cooling Type:

Liquid Cooled

Oil Capacity:

4.5 Liters (4.8 US Quarts) with filter

Recommended Oil Viscosity:

SAE 5W-30 or 5W-40 (synthetic blend recommended)

Timing Belt Interval:

50,000 - 60,000 miles or 4-5 years (critical replacement interval due to interference engine design)

🔧 Transmission

Standard Transmission Type:

5-speed Manual (013)

Optional Transmission Type:

4-speed Automatic (014)

Quattro AWD Availability:

Optional on both manual and automatic transmissions.

Manual Transmission Fluid Spec:

GL-4 75W-90 Gear Oil

Automatic Transmission Fluid Spec:

G 052 162 A1 (or equivalent ATF Dexron III)

📐 Dimensions

Length:

172.7 inches

Width:

66.3 inches

Height:

54.5 inches

Wheelbase:

101.3 inches

Curb Weight:

2900-3100 lbs (FWD manual) / 3100-3300 lbs (Quattro)

Gross Vehicle Weight Rating:

Approx. 4000 lbs

Trunk Volume:

Approx. 14.0 cubic feet

Standard Wheel Size:

14 inch alloy or steel wheels

Optional Wheel Size:

15 inch alloy wheels

Standard Tire Size:

185/65R14

Wheel Bolt Pattern:

5x112mm

🛡️ Safety Features

NHTSA Frontal Impact:

Not explicitly rated by NHTSA for this model year, but generally considered a safe vehicle for its era.

Active Safety Features:

Anti-lock Braking System (ABS) - standard on most models, especially Quattro. Excellent Quattro AWD system providing superior traction and stability.

Passive Safety Features:

Reinforced safety cell, impact-absorbing crumple zones, energy-absorbing steering column, front seat belts with pretensioners, rear seat belts, reinforced doors.

💡 Technology Features

Infotainment System:

Basic AM/FM stereo radio with cassette player, often with premium speaker options (e.g., Audi Sound System). Manual climate control knobs and ventilation controls.

Driver Assistance Features:

ABS (Anti-lock Braking System) was the primary advanced driver assistance feature. Quattro AWD provided significant traction and stability assistance.

Connectivity Features:

Limited to analog systems; no integrated Bluetooth, USB, or navigation. Optional cruise control.

Lighting Features:

Halogen headlights, incandescent taillights and turn signals. Manual headlight aiming adjustment.

🔧 Maintenance

Oil Change Interval:

Every 5,000-7,500 miles or 6-12 months, depending on driving conditions and oil type used.

Air Filter Replacement:

Every 15,000-20,000 miles or as needed based on inspection.

Cabin Filter Replacement:

Not equipped with a cabin air filter in this generation.

Fuel Filter Replacement:

Every 30,000 miles.

Brake Fluid Flush:

Every 2 years or 30,000 miles.

Engine Coolant:

G 11 (Blue or Green) or equivalent OAT/HOAT coolant (50/50 mix with distilled water).

Power Steering Fluid:

G 002 000 (Pentosin CHF 11S) or equivalent hydraulic fluid.

Windshield Washer Fluid:

Water/Washer Fluid Concentrate mix.

Known Issues:

Timing belt failure (due to age and lack of replacement), coolant flange leaks (plastic components), electrical gremlins (aged wiring, grounds), ABS sensor failures, exhaust manifold cracks (5-cylinder engine), door seal deterioration, vacuum hose deterioration.

Common Repairs:

Timing belt and water pump replacement, coolant flange replacement, CV axle replacement, brake component refurbishment, suspension bushings replacement.

📚 Vehicle History

Brand Heritage:

Audi, a German manufacturer with a history dating back to the early 20th century, is known for its engineering prowess, quattro all-wheel-drive technology, and premium vehicle offerings. The brand emphasizes 'Vorsprung durch Technik' (Advancement through Technology).

Model Evolution:

The Audi 90 (Type 85, B3 generation) was a significant evolution from its predecessor, the Audi 80/90 (Type 81). It introduced a more aerodynamic design, improved chassis dynamics, and further refinement of its powertrain and technology. It was later succeeded by the Audi 80/A4 in 1995.

Production Period:

1984-1991 (Type 85/B3 generation)

Production Location:

Ingolstadt, Germany and Neckarsulm, Germany

🏆 Awards & Recognition

Recognitions:

While specific awards for the 1990 model are not widely documented, the Audi 90 and its Quattro system were highly regarded for their performance, handling, and all-weather capability by automotive journalists of the era.

Ratings:

Consistently praised for its comfortable ride, sophisticated engineering, and the effectiveness of the Quattro system in challenging conditions.