🏷️ Basic Information Identification Make: Audi Model: A4 Model Variants: S4, RS4 Avant, Allroad Chassis Codes: 8D, 8D2, 8D5 Model Year: 1998 👋 Introduction Market Position Segment: Premium compact executive car Competitive Analysis Competitors 1998: BMW 3 Series (E46), Mercedes-Benz C-Class (W202), Lexus IS Key Features Platform Basis: Volkswagen Group B5 platform (shared with Volkswagen Passat B5) Powertrain Options: Quattro all-wheel drive available on many models, renowned for stability and traction Design Philosophy: Understated elegance, build quality, and driver-focused interior 📋 Manual Details Coverage Areas Primary Coverage: Full factory service and repair Model Scope: All Audi A4 models (1998) including S4, RS4 Avant, and Allroad variants Page Count Total Pages: 14487 Manual Type Type: Factory Service Manual Language Language: English Format File Format: PDF 📖 Manual Coverage Systems Covered Powertrain: Mechanical Engine, Transmission (Manual & Automatic), Driveline Axle Chassis: Brakes, Steering, Suspension, Tires & Wheels Electrical: Complete Electrical System, Lights, Restraints (Airbags), Wiring Diagrams Body And Interior: Body & Frame - Interior & Exterior, Accessories & Equipment Comfort And Climate: HVAC (Heating, Ventilation, and Air Conditioning) Infotainment: Audio, Visual & Telematics Procedures Included Maintenance: Scheduled maintenance, fluid changes, filter replacements, lubrication Diagnostics: Troubleshooting guides, fault code interpretation, diagnostic procedures Repair: Component removal, installation, adjustment, and overhaul Overhaul: Detailed engine, transmission, and differential rebuild procedures Electrical Repair: Component testing, wiring harness repair, connector servicing Technical Depth Depth: Comprehensive, from basic fluid checks to complete engine and transmission rebuilds Detail Level: Factory-level diagnostic procedures, torque specifications, and repair sequences 📊 Manual Specifications File Format Quality: High-resolution, suitable for printing Searchability: Fully searchable text Print Quality Printability: Printable in entirety or by specific pages Compatibility Operating Systems: Windows and Mac compatible Requirements Software: Adobe PDF Reader, WinRar Delivery Method: Instant Download ⚙️ Engine Specifications Primary Engine A4 1.8T: 1.8L turbocharged inline-4 (APU, ARK, AUH, AVC, AWV, AWM engines) A4 2.8 V6: 2.8L naturally aspirated V6 (AFC, AHA, ATX, AMX engines) S4 2.7 Bi-Turbo: 2.7L twin-turbocharged V6 (APB, AGB engines) Rs4 Avant Bi-Turbo: 2.7L twin-turbocharged V6 (ASJ, AZR engines) Performance 1.8T: 150-180 hp (depending on variant and tune) 2.8 V6: 190-204 hp (depending on variant) S4 2.7 Bi-Turbo: 250-265 hp Rs4 Avant 2.7 Bi-Turbo: 375-380 hp Fuel System Injection Type: Multi-point fuel injection (MPI) or direct injection (FSI in later models, but primarily MPI for 1998) Fuel Type: Premium Unleaded Gasoline (91 RON or higher recommended) 🔧 Transmission Standard A4 1.8T: 5-speed Manual A4 2.8 V6: 5-speed Manual or 5-speed Tiptronic Automatic S4/Rs4: 6-speed Manual Optional A4 1.8T: 5-speed Tiptronic Automatic Features AWD Availability: Quattro permanent all-wheel drive system available on most variants 📐 Dimensions Exterior Length Sedan: ~4.52 m (~178 in) Length Avant: ~4.58 m (~180 in) Weights Curb Weight Range: ~1450 - 1700 kg (~3197 - 3748 lbs) depending on model and equipment 🛡️ Safety Features Ratings IIHS Front Impact: Good (for models tested) NHTSA Side Impact: 4-star (for models tested) Active Features ABS: Standard Anti-lock Braking System Esc: Electronic Stability Control (ESP) available on some models Passive Features Airbags: Frontal airbags, side airbags available Seatbelts: 3-point inertia reel seatbelts with pre-tensioners 💡 Technology Features Infotainment Audio Systems: Factory Audi Symphony and Concert sound systems, optional Bose audio Navigation: Optional Audi Navigation Plus system (CD-ROM based) Driver Assistance Cruise Control: Standard cruise control on most models Connectivity Phone Integration: Optional integrated mobile phone preparation 🔧 Maintenance Service Intervals Oil Change Interval: Typically 7,500 to 10,000 miles (12,000 to 16,000 km) or 12 months, whichever comes first, depending on driving conditions and oil quality used (consult manual for specific recommendations) Timing Belt Replacement V6: Recommended every 60,000 - 80,000 miles or 5-7 years for V6 engines. Consult manual for exact interval and engine code. Timing Belt Replacement Turbo: The 1.8T engine uses a timing belt; interval typically 60,000 - 80,000 miles or 5-7 years. The V6 engines also have timing belts. Fluid Specifications Engine Oil 1.8T: SAE 5W-40 or 5W-30 synthetic oil meeting VW 502 00 / 505 00 specifications Engine Oil 2.8V6: SAE 5W-40 or 5W-30 synthetic oil meeting VW 502 00 / 505 00 specifications Coolant: G12 or G12+ ethylene glycol coolant (pink) mixed 50/50 with distilled water Brake Fluid: DOT 4 synthetic brake fluid Transmission Fluid Manual: API GL-4 or GL-5 gear oil, SAE 75W-90 (check manual for specific Audi specifications) Transmission Fluid Automatic: Audi G 052 162 A2 (or equivalent ATF meeting VW TL 521 62 specification) Known Issues Coil Packs: Ignition coil pack failure can cause misfires and rough running (common on 1.8T) Cv Boots: Torn Constant Velocity (CV) boots leading to noise and damage Window Regulators: Failure of the power window regulator mechanisms Oil Leaks: Valve cover gasket and oil pan gasket leaks can occur with age ABS Sensor: ABS wheel speed sensor failures can illuminate ABS and Traction Control warning lights 📚 Vehicle History Brand Heritage...