🏷️ Basic Information

Make:

Mercedes-Benz

Model:

S-Class

Model Code:

W140

Year:

1998

Variant:

S320, S420, S500

Generation Designation:

Third Generation (W140)

👋 Introduction

Market Segment:

Full-size Luxury Sedan

Brand Perception:

Represents the pinnacle of Mercedes-Benz engineering and luxury for its era, competing with other high-end luxury sedans.

Primary Competitors 1998:

BMW 7 Series (E38), Audi A8 (D2), Lexus LS 400 (XF20), Cadillac DeVille.

Build Quality:

Renowned for robust construction and high-quality materials, a hallmark of Mercedes-Benz engineering.

Comfort And Refinement:

Exceptional ride quality, quiet cabin, and advanced climate control systems provide supreme comfort.

Technological Advancements:

Incorporated many then-cutting-edge technologies in safety, comfort, and convenience.

Ownership Benefit:

Essential for understanding and maintaining the complex systems of the W140 S-Class, ensuring optimal performance and longevity.

Information Accessibility:

Provides instant access to critical operational and maintenance information in a convenient digital format.

📋 Manual Details

Coverage Focus:

Operation, Maintenance, Safety, Comfort, and Emergency Procedures for 1998 Mercedes-Benz S-Class W140 models.

Estimated Page Count:

Approximately 300-400 pages (typical for this era and model complexity)

Manual Type:

Owner's Manual

Language:

English

File Format:

PDF

📖 Manual Coverage

Engine And Powertrain:

Detailed information on engine operation, fluid checks, basic troubleshooting, and recommended maintenance for the M104 (S320), M119 (S420/S500) engines.

Chassis And Suspension:

Explanation of the sophisticated independent suspension system, tire inflation, and basic checks.

Brakes And Steering:

Information on brake system operation, ABS, and power steering system checks.

Electrical System:

Overview of the electrical system, fuse box locations, battery maintenance, and lighting operation.

Comfort And Convenience:

Detailed coverage of climate control (THERMATIC/THERMOTRONIC), power seats, windows, mirrors, sunroof, and door locks.

Infotainment And Audio:

Operation of the factory audio system, antenna, and potentially early mobile phone integration or voice recognition systems if equipped.

Safety Systems:

Comprehensive explanation of SRS (Supplemental Restraint System) - airbags, seat belts, and their proper usage and care.

Pre Driving Checks:

Guidance on essential checks before starting a journey, including fluid levels, tire pressure, and visual inspections.

Starting And Driving:

Instructions on vehicle startup, gear selection (P, R, N, D, etc.), and basic driving techniques for optimal performance and safety.

Emergency Situations:

Procedures for handling common emergencies such as tire changes, jump starting, coolant leaks, and using hazard warning lights.

Maintenance Diy:

Guidance on routine maintenance tasks the owner can perform, such as checking and topping up fluids, replacing wiper blades, and basic cleaning.

Appearance And Care:

Recommendations for interior and exterior cleaning, protecting paintwork, and maintaining the vehicle's aesthetic appeal.

Technical Depth:

Owner-level understanding and basic maintenance. Does not include detailed diagnostic procedures or component-level repair instructions typical of a Service Manual.

📊 Manual Specifications

Compatibility:

All Versions of Windows & Mac

Downloadability:

YES

Requirements:

Adobe PDF Reader

Digital Quality:

High-resolution scans or digital originals, ensuring clarity of text and diagrams.

Binding Type:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

⚙️ Engine Specifications

Engine Code:

M104.990 (US Spec)

Engine Type:

3.2L Inline 6-Cylinder

Displacement:

3199 cc

Horsepower:

228 hp @ 5500 rpm

Torque:

232 lb-ft @ 3750 rpm

Fuel System:

Bosch Motronic MFI (Multi-Point Fuel Injection)

Engine Code:

M119.971 (US Spec)

Engine Type:

4.2L V8

Displacement:

4196 cc

Horsepower:

275 hp @ 5750 rpm

Torque:

295 lb-ft @ 3750 rpm

Fuel System:

Bosch Motronic MFI (Multi-Point Fuel Injection)

Engine Code:

M119.972 (US Spec)

Engine Type:

5.0L V8

Displacement:

4973 cc

Horsepower:

315 hp @ 5600 rpm

Torque:

347 lb-ft @ 3900 rpm

Fuel System:

Bosch Motronic MFI (Multi-Point Fuel Injection)

Engine Management System:

OBD-II Compliant

Recommended Fuel:

Premium Unleaded Gasoline (91+ Octane)

🔧 Transmission

Transmission Type:

4-Speed Automatic (4G-TRONIC)

Optional Transmission:

N/A (All W140 models in this year typically came with the 4-speed automatic)

Transmission Features:

Electronic control, multiple shift modes (e.g., Comfort/Sport) may be present depending on specific model configuration.

Transmission Fluid Type:

Mercedes-Benz Automatic Transmission Fluid (ATF) Specification 236.10 or equivalent (e.g., Shell ATF 3403 M-115).

📐 Dimensions

Wheelbase:

118.9 inches (3020 mm)

Overall Length:

201.0 inches (5105 mm)

Overall Width:

74.6 inches (1895 mm)

Overall Height:

57.8 inches (1468 mm)

Curb Weight S320:

Approximately 4400-4600 lbs (2000-2100 kg)

Curb Weight S500:

Approximately 4600-4800 lbs (2100-2200 kg)

Gross Vehicle Weight Rating:

Typically around 5730-5900 lbs (2600-2675 kg)

Towing Capacity:

Not specified for this model, generally not designed for towing.

🛡️ Safety Features

NHTSA Ratings:

Specific NHTSA ratings for 1998 W140 are not readily available in a summarized format. However, the W140 was designed with significant safety advancements for its time.

Antilock Brakes:

Standard (ABS)

Traction Control:

Standard (ASR - Acceleration Slip Regulation)

Airbags:

Driver and front passenger airbags (SRS), side airbags may have been optional on some models.

Seat Belts:

Three-point inertia-reel seat belts with front belt tensioners.

Body Structure:

Reinforced passenger cell and crumple zones.

💡 Technology Features

Audio System:

Factory-installed AM/FM stereo with cassette player, potentially CD changer integration. Features like seek tuning, presets, and tone controls are standard.

Climate Control:

THERMATIC (automatic climate control) or THERMOTRONIC (dual-zone automatic climate control) with digital displays and numerous vents for optimal cabin temperature regulation.

Navigation System:

Optional factory navigation system (often map-based) may have been available.

Cruise Control:

Standard electronic cruise control.

Parking Assist:

Optional rear parking assist sensors may have been available.

Telephone System:

Factory-installed or dealer-installed car phone/GSM system, typically with a handset and display integrated into the dashboard or armrest.

Voice Recognition:

Limited voice recognition capabilities may have been present for certain functions (e.g., phone operation) on some models.

🔧 Maintenance

Oil Change Interval:

Typically every 7,500-10,000 miles (12,000-16,000 km) or annually, whichever comes first, depending on driving conditions and oil used. Consult the manual for specific service indicators (e.g., 'Service A', 'Service B').

Transmission Fluid Interval:

Recommended at 60,000 miles (96,000 km) or as per service indicator, though many owners opt for more frequent changes.

Coolant Change Interval:

Typically every 2-3 years or 30,000-50,000 miles (48,000-80,000 km).

Engine Oil Type:

Synthetic engine oil, typically meeting MB 229.1 or MB 229.3 specifications (e.g., Mobil 1 0W-40, Castrol SYNTEC 0W-30).

Coolant Type:

Mercedes-Benz Approved Antifreeze/Coolant (e.g., Zerex G-05 or equivalent).

Brake Fluid Type:

DOT 3 or DOT 4 brake fluid.

Wiring Harness:

Some older Mercedes-Benz models can experience degradation of the engine wiring harness insulation ('biodegradable wiring'), leading to intermittent electrical issues. The manual will not detail repair, but proper care can mitigate some issues.

Mass Air Flow Sensor:

Can become dirty or fail, affecting engine performance and fuel economy.

Coolant Leaks:

Plastic coolant pipes and reservoirs can become brittle over time and develop leaks.

Window Regulators:

Can fail, preventing windows from operating correctly.

Door Locks:

Vacuum-operated door locks can sometimes malfunction due to leaks in the vacuum lines.

Tire Pressure Recommendation:

Recommended pressures are typically found on a sticker in the driver's side door jamb or in the manual itself. Varies based on load and tire size (e.g., 32-35 PSI).

Washer Fluid:

Use a mixture of windshield washer fluid and distilled water, or a dedicated summer/winter blend.

📚 Vehicle History

Manufacturer Heritage:

Mercedes-Benz has a long-standing reputation for luxury, engineering excellence, and safety dating back to the early 20th century.

W140 Introduction:

The W140 generation replaced the W126 S-Class and was produced from 1991 to 1998 (model years). It was a significant departure in size, technology, and styling.

1998 Updates:

The 1998 model year represents the final year of the W140 generation. Minor updates may have occurred throughout its production life, including slight engine power bumps or feature adjustments.

Production Period:

1991-1998

Production Locations:

Primarily Germany (Sindelfingen) and also assembled in other locations for specific markets.

🏆 Awards & Recognition

Overall Reputation:

While specific awards for the 1998 model are not prominently highlighted, the W140 generation generally received critical acclaim for its engineering, comfort, and safety features, cementing Mercedes-Benz's position in the luxury segment.

Safety Awards:

Mercedes-Benz vehicles of this era consistently scored well in independent safety assessments due to advanced engineering.