🏷️ Basic Information Identification Make: Mercedes-Benz Model: S420 Year: 1998 Codes Chassis Code: W140 Engine Code: M119 (V8) 👋 Introduction Market Position Segment: Full-Size Luxury Sedan Key Competitors: BMW 7 Series, Lexus LS, Audi A8, Jaguar XJ Key Features Luxury Appointments: Exceptional ride comfort, high-quality interior materials, advanced features for its era Engineering: Robust M119 V8 engine, advanced independent suspension, sophisticated electronic systems Value Proposition: Access to detailed factory service information for a premium luxury vehicle 📋 Manual Details Coverage Areas Primary Coverage: Mechanical, Electrical, Bodywork, Diagnostics Secondary Coverage: Maintenance Schedules, Troubleshooting Guides, Wiring Diagrams Page Count Estimated Pages: 1500+ Manual Type Type: Official Factory Service Manual Language Language: English Format Format: Software (likely PDF or proprietary digital format) 📖 Manual Coverage Systems Covered Engine: 4.2L V8 (M119.985), Fuel System (EFI), Ignition System, Cooling System, Exhaust System, Lubrication System Transmission: 4-Speed Automatic (722.6 '5G-Tronic') Drivetrain: Rear Wheel Drive (RWD) Suspension: Front: Independent Multi-Link, Rear: Independent Multi-Link, Self-Leveling Suspension (SLS) details Brakes: Front: Ventilated Discs, Rear: Ventilated Discs, ABS (Anti-lock Braking System), ESP (Electronic Stability Program) Steering: Hydraulic Power Steering, Speed-Sensitive Steering Electrical: Charging System, Starting System, Lighting, Instruments, Body Control Modules (BCM), CAN Bus communication (limited) Climate Control: Automatic Climate Control (Thermotronic), HVAC System Components Body: Body Exterior Panels, Doors, Hood, Trunk, Glass, Upholstery, Body Repair Safety Systems: Airbags (Front, Side), Seatbelt Pre-tensioners, Crumple Zones Procedures Included Maintenance: Oil Change, Filter Replacement, Fluid Checks and Changes, Spark Plug Replacement, Belt Inspection and Replacement Troubleshooting: Diagnostic Trouble Codes (DTCs), Symptom-Based Diagnosis, Component Testing Repair: Engine Overhaul, Transmission Rebuild, Suspension Component Replacement, Brake System Repair, Electrical Component Diagnosis and Replacement Diagnostics: Scan Tool Procedures (OBD-II), Live Data Interpretation, Component Actuation Tests Wiring Diagrams: Comprehensive Electrical Schematics for all Systems Technical Depth Depth: Comprehensive Factory Level Detail, Suitable for Professional Technicians and Advanced DIY Enthusiasts Rebuilds: Engine and Transmission Rebuild Procedures Included Calibrations: Key Component Calibrations (e.g., Throttle Body, ABS Sensors) covered 📊 Manual Specifications File Format Software Type: Digital, likely searchable PDF or proprietary application Print Quality Resolution: High-resolution, suitable for printing Binding Type Binding: N/A (Software) Paper Type Paper: N/A (Software) Searchability Text Search: Yes, fully text-searchable ⚙️ Engine Specifications Primary Engine Type: V8, Naturally Aspirated Displacement: 4.2 Liters (4196 cc) Bore X Stroke: 88.0 mm x 86.0 mm Compression Ratio: 10.0:1 Performance Horsepower: 275 hp @ 5700 rpm Torque: 295 lb-ft @ 3900 rpm Fuel System Induction: Multi-point Fuel Injection (Bosch LH-Jetronic) Fuel Type: Premium Unleaded Gasoline (91 Octane or higher) Lubrication Oil Type: SAE 5W-40 or 0W-40 Synthetic (MB Approved) Oil Capacity: 8.0 Liters (8.5 US Quarts) 🔧 Transmission Standard Type: 4-Speed Automatic (722.6 '5G-Tronic') Optional Type: N/A for S420 Features Shifting Modes: Comfort, Sport Fluid Specs Fluid Type: MB 236.10 or MB 236.14 Specification ATF (Dexron III compatible if specified by manufacturer) 📐 Dimensions Exterior Length: 5150 mm (202.8 in) Width: 1890 mm (74.4 in) Height: 1440 mm (56.7 in) Wheelbase Wheelbase: 3140 mm (123.6 in) Weights Curb Weight: Approx. 1950 kg (4300 lbs) Gross Weight: Approx. 2510 kg (5535 lbs) 🛡️ Safety Features Ratings Crash Test Data: NHTSA/IIHS data for this specific year may be limited; focus on design intent and features. Active Features ABS: Standard Anti-lock Braking System Esp: Standard Electronic Stability Program (from 1997 onwards) Traction Control: ASR (Anti-Slip Regulation) Passive Features Airbags: Driver and Passenger Front Airbags, Optional Side Airbags Seatbelts: Pre-tensioning Seatbelts with Force Limiters Body Structure: High-strength steel chassis with energy-absorbing crumple zones 💡 Technology Features Infotainment Audio System: Factory premium sound system, likely with cassette and optional CD changer. Manual covers basic diagnostics and speaker replacement. Navigation: Optional COMAND system (less common on S420, more on V8 and V12 models, and later years). Driver Assistance Cruise Control: Standard electronic cruise control. Parking Sensors: Optional front and rear Parktronic sensors. Connectivity Tel System: Optional cellular telephone integration. 🔧 Maintenance Service Intervals Oil Change Interval: Every 10,000 miles or 12 months, whichever comes first (using synthetic oil) Transmission Service: Every 60,000 miles or 4 years (fluid and filter replacement) Coolant Service: Every 30,000 miles or 3 years (using Mercedes-Benz approved coolant) Spark Plugs: Every 100,000 miles (Long Life Spark Plugs) Fluid Specifications Coolant Type: Mercedes-Benz Specification 325.0 (Glysantin G48 or equivalent Blue/Green OAT) Brake Fluid: DOT 4 Known Issues Head Gaskets: While M119 is robust, head gasket leaks can occur due to age/overheating. Manual provides inspection and repair procedures. Cooling System: Plastic coolant reservoir brittle, hose degradation, water pump leaks are common. Manual details replacement. Window Regulators: Known to fail; manual covers diagnosis and replacement. Door Locks: Vacuum-operated door locking system can develop leaks. Manual provides troubleshooting for the system. Electronics: Age-related failures in various electronic modules (e.g., EZL, EIS, ABC control modules if equipped on later W140 models, though S420 likely has SLS). Manual covers diagnostic approaches. 📚 Vehicle History Brand Heritage...