🏷️ Basic Information

Make:

Mercedes-Benz

Model:

300SE

Year:

1992

Chassis Code:

W140

Engine Code:

M104.990

👋 Introduction

Market Position:

The 1992 Mercedes-Benz 300SE (W140 chassis) represented the pinnacle of German engineering and luxury automotive design for its era, targeting the premium executive sedan segment. This manual caters to owners and technicians maintaining this sophisticated vehicle.

Competitive Analysis:

Competed against flagship models from BMW (7 Series), Audi (V8/A8), Lexus (LS 400), and Jaguar (XJ). The W140 was known for its robust build quality, advanced technology, and superior ride comfort, often surpassing competitors in these areas, albeit at a higher price point.

Key Features:

Dual overhead camshafts, electronic fuel injection, anti-lock braking system (ABS), extensive use of sound deadening, advanced climate control, and a spacious, opulent interior.

📋 Manual Details

Coverage Areas:

Comprehensive Service, Repair, Diagnostics, Electrical Schematics, Wiring Diagrams, Maintenance Schedules, Troubleshooting

Page Count:

Extensive (typical for official factory manuals, often exceeding 1500 pages in print equivalent)

Manual Type:

Official Factory Service & Repair Manual Software

Language:

English

Format:

Software (likely digital, possibly PDF or proprietary application)

📖 Manual Coverage

Systems Covered:

Engine Mechanical, Engine Management (DOHC, Fuel Injection - KE-Jetronic/HFM, Ignition), Transmission (4-Speed Automatic - 722.4, possible 5-Speed - 722.5), Drivetrain, Suspension (Front Independent - MacPherson Strut, Rear Independent - Multi-Link), Brakes (ABS - Bosch), Steering (Hydraulic Power Assist), Fuel System, Cooling System, Exhaust System, Climate Control (Automatic Climate Control - THERMATIC/THERMOTRONIC), Electrical System, Body Control Modules, Lighting, Audio System, Bodywork, Interior Trim, Diagnostic Trouble Codes (DTCs), Component Testing, Component Replacement, Specifications, Torque Values

Procedures Included:

Scheduled Maintenance, General Repairs, Engine Overhaul, Transmission Overhaul, Brake System Repair, Suspension Component Replacement, Steering System Repair, Electrical System Troubleshooting, Wiring Harness Repair, Climate Control System Servicing, Diagnostic Procedures, Component Removal and Installation, Body Panel Repair, Interior Component Repair, Emissions Control System Repair

Technical Depth:

In-depth, factory-level detail including diagnostic flowcharts, component specifications, repair procedures, and torque specifications. Suitable for professional technicians and advanced DIY enthusiasts.

📊 Manual Specifications

File Format:

Digital Software (Specific format depends on provider, often searchable PDF or proprietary executable)

Print Quality:

N/A (Digital Format)

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Primary Engine:

3.0L Inline-6 Cylinder (M104.990)

Horsepower:

Approx. 217 hp @ 6000 rpm

Torque:

Approx. 228 lb-ft @ 4400 rpm

Fuel System:

Bosch KE-Jetronic Electronic Fuel Injection with Electronic Control

Valvetrain:

DOHC, 4 Valves per Cylinder

Bore X Stroke:

88.5 mm x 80.2 mm

Compression Ratio:

9.2:1

🔧 Transmission

Transmission Type:

4-Speed Automatic (722.4)

Transmission Type:

5-Speed Automatic (722.5, less common for 300SE)

Transmission Features:

Electronically controlled, hydraulic torque converter, lock-up clutch for efficiency

Transmission Fluid Type:

MB 236.1 (e.g., Mobil ATF 220, Pentosin ATF 1)

📐 Dimensions

Length:

Approx. 5113 mm (201.3 in)

Width:

Approx. 1886 mm (74.3 in)

Height:

Approx. 1467 mm (57.8 in)

Wheelbase:

Approx. 3040 mm (119.7 in)

Curb Weight:

Approx. 1830 kg (4034 lbs)

🛡️ Safety Features

Safety Ratings:

NHTSA ratings for this era are not directly comparable to modern standards. Vehicle construction prioritized passive safety through robust chassis design and materials.

Active Safety Features:

Anti-lock Braking System (ABS)

Passive Safety Features:

Reinforced safety cage, crumple zones, dual front airbags (optional/standard depending on market), seatbelt pre-tensioners, impact-absorbing steering column.

💡 Technology Features

Infotainment System:

Factory-installed AM/FM radio with cassette player, optional CD changer. Features were advanced for the era, with high-quality audio components.

Driver Assistance Features:

Cruise Control, Parking Assist (optional front sensors), rain-sensing wipers (later models/optional).

Connectivity Features:

Limited by era, primarily internal vehicle system communication. External connectivity was not a feature.

Comfort Features:

Dual-zone automatic climate control (THERMATIC/THERMOTRONIC), heated and ventilated seats (optional), power-adjustable front seats with memory, power tilt/telescoping steering wheel, power windows, power sunroof, soft-close doors and trunk.

🔧 Maintenance

Oil Change Interval:

Typically every 10,000-15,000 km (6,000-9,000 miles) or 12 months, depending on driving conditions and oil type. Refer to manual for specific interval based on ASSYST system or mileage.

Transmission Service Interval:

Fluid and filter change recommended every 60,000-80,000 km (40,000-50,000 miles).

Engine Oil Type:

API SG/SH, ACEA A2-96 or MB 229.1 specification. Viscosity typically 0W-40, 5W-40, 5W-50, or 10W-40 depending on climate. Consult manual for exact recommendations.

Coolant Type:

MB 325.0 / 326.0 (Ethylene Glycol based, blue or green color)

Brake Fluid Type:

DOT 4

Common Issues:

Vacuum leaks in the pneumatic system (door locks, climate control actuators), OVP relay failure, biodegradable wiring insulation degradation, ABS sensor faults, window regulator issues, cooling system hose deterioration, BECK/APA module failures, catalytic converter issues (rare).

Oil Filter Part Number:

Example: Mann-Filter HU 718/1x, Bosch 72242 (Verify specific part for M104.990)

Air Filter Part Number:

Example: Mann-Filter C 3412/2 (Verify specific part for M104.990)

📚 Vehicle History

Brand Heritage:

Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, safety, and durability dating back to the late 19th century.

Model Evolution:

The W140 S-Class generation replaced the W126 and was a significant technological leap, introducing features like CAN bus communication, dual-pane acoustic glass, Xenon headlamps (later in the run), and advanced climate control. It aimed to redefine the luxury sedan standard.

Production Years:

1991-1998 (W140 chassis)

Manufacturing Location:

Germany (Sindelfingen plant)

🏆 Awards & Recognition

Recognitions:

While specific awards for the 1992 model year might be scarce, the W140 generation consistently received acclaim for its engineering, build quality, and luxury features, setting benchmarks for the automotive industry.

Ratings:

Owner satisfaction and reliability ratings were generally high, though complex systems could require specialized maintenance. Recognized for its long-term durability.