🏷️ Basic Information

Make:

Mercedes-Benz

Model:

S-Class

Chassis Code:

W140

Coupe Chassis Code:

C140

Model Year:

1997

👋 Introduction

Positioning:

The W140/C140 generation of the Mercedes-Benz S-Class represented the pinnacle of automotive engineering and luxury for its era. This manual caters to owners and independent workshops seeking the same level of technical detail and accuracy as dealership technicians.

Advantage:

Unlike generic repair guides, this manual is vehicle-specific, providing exact procedures and specifications for the W140/C140, ensuring accurate and efficient repairs. Its digital format offers convenience and portability.

Features:

Includes complete step-by-step instructions, diagrams, illustrations, wiring schematics, and specifications. Offers a single, easy-to-use PDF for all repair needs, reducing the need to handle physical manuals.

Audience:

Owners of 1997 Mercedes-Benz S-Class (W140) and CL-Class (C140) vehicles, independent repair shops, DIY enthusiasts, and automotive technicians.

📋 Manual Details

Primary Coverage:

Comprehensive service, repair, and maintenance for 1997 Mercedes-Benz S-Class (W140) and CL-Class (C140) models.

Scope:

All models and all repairs A-Z, vehicle-specific.

Estimated Pages:

N/A (Digital PDF format, content extent is comprehensive rather than a fixed page count).

Type:

Factory Service and Repair Manual

Language:

English

Format:

Digital PDF

📖 Manual Coverage

Powertrain:

Engine (M119, M120, OM60x variants), Fuel Service Specifications, Emission Control, Intake/Exhaust Systems, Cooling Systems, Lubrication Systems, Ignition System, Starting & Charging Systems, Automatic Transmission (e.g., 722.6 '5G-Tronic'), Manual Transmission (if applicable to specific sub-models), Transfer Case (if applicable), Drive Shaft, Differential, Axles.

Chassis And Body:

Suspension (Front & Rear), Steering Column, Power Steering, Brake Control Systems, Brake Systems (Front & Rear), Parking Brake, Tire & Wheel Specifications.

Electrical And Electronics:

Electrical System Overview, Wiring Schematics, Supplemental Restraint System (SRS) / Airbag System, Seat Belt Systems, Engine Immobilizer, Cruise Control, Wiper & Washer System, Door Lock Systems, Meter & Instrument Panel, Audio/Visual Systems, Horn, Windshield/Glass/Mirrors, Exterior & Interior Lighting, Multiplex Communication / CAN Bus Systems.

Climate Control:

Automatic climate control system, including A/C compressor, heater core, blower motor, climate control modules, and recirculation system.

Body And Interior:

Engine Hood/Door (latches, hinges, struts), Exterior & Interior trim, Seats (adjustment mechanisms, heating elements), Door Locks, Windows and Glass (mechanisms, seals).

Fuel System:

Fuel pump, fuel injectors, fuel pressure regulator, fuel filter, fuel tank, electronic fuel management systems.

Cooling System:

Radiator, water pump, thermostat, coolant hoses, expansion tank, cooling fan, climate control integration.

Maintenance:

Scheduled maintenance tasks, fluid level checks and changes, filter replacements, spark plug replacement, belt inspection and replacement.

Diagnosis:

Troubleshooting guides, diagnostic procedures for various systems, fault code interpretation (where applicable).

Repair:

Step-by-step repair instructions for all major components and systems, including engine overhauls, transmission rebuilds, brake caliper replacement, suspension component renewal, electrical component diagnosis and repair, body panel repair and replacement.

Technical Specifications:

Detailed specifications for all components, torque values, fluid capacities, electrical values, diagnostic parameters.

Diagnostic Tools:

Procedures will cover the use of diagnostic tools and equipment commonly used by Mercedes-Benz technicians for this era.

Depth:

Factory-level, comprehensive. Covers everything from basic fluid changes to complex electronic diagnostics and major mechanical component rebuilds. Includes detailed diagrams and schematics.

📊 Manual Specifications

Compatibility:

Windows Vista (32/64-bit), XP, ME, 98, NT, 2000, and Mac compatible.

Required Software:

Adobe PDF Reader and WinZip (free online).

Searchability:

PDF format is typically searchable, allowing users to quickly locate specific topics or components.

Printability:

All pages are printable. Allows for blow-up of images and printing of enlarged copies.

Binding:

N/A (Digital format, no physical binding).

Paper:

N/A (Digital format, no physical paper).

⚙️ Engine Specifications

Engine Options 1997:

Likely includes variants of the M119 V8 (e.g., 4.2L, 5.0L) and M120 V12 (e.g., 6.0L). Diesel options (OM60x variants) were also available in some markets.

Engine Displacement Common:

Common V8 displacements include 4.2L (4196 cc) and 5.0L (4973 cc). Common V12 displacement is 6.0L (5987 cc).

Horsepower Torque Estimates:

Varies significantly by engine. For example, the M119 5.0L typically produced around 322 hp and 391 lb-ft torque, while the M120 6.0L produced around 402 hp and 420 lb-ft torque.

Fuel Injection:

Bosch Motronic electronic fuel injection (EFI) system, or similar sophisticated fuel management systems.

Specific Engine Codes:

Likely covers M119.970 (4.2L V8), M119.972 (5.0L V8), M120.982 (6.0L V12), and potentially OM603.972 (3.5L Turbo Diesel) or OM606.971 (3.0L Turbo Diesel) depending on market.

🔧 Transmission

Transmission Type Common:

4-speed automatic (e.g., 722.3, 722.4) or the newer 5-speed automatic (722.6 '5G-Tronic') depending on specific model variant and market.

Manual Transmission Availability:

Manual transmissions were extremely rare or not offered on W140/C140 models in most major markets, especially in North America. The manual covers it if fitted, but primarily focuses on automatics.

Automatic Transmission Features:

Features such as Comfort/Sport modes, electronic control, and adaptive shifting for the 722.6 transmission.

Torque Converter Lockup:

Details on torque converter lockup clutch operation and control for automatic transmissions.

📐 Dimensions

Wheelbase W140:

Standard wheelbase: 3,139 mm (123.6 in). Long wheelbase: 3,266 mm (128.6 in).

Wheelbase C140:

Approx. 2,915 mm (114.8 in).

Curb Weight Estimate:

Curb weight typically ranged from approximately 1,900 kg (4,189 lbs) to over 2,100 kg (4,630 lbs) depending on engine and equipment.

Gross Vehicle Weight Rating Gvwr Estimate:

GVWR typically in the range of 2,500 kg to 2,700 kg, depending on specific model and engine configuration.

🛡️ Safety Features

Crash Test Information:

While specific ratings for 1997 may vary by region, the W140 was designed with significant safety features for its time, including a very robust chassis.

Active Safety Systems:

Anti-lock Braking System (ABS), Traction Control System (ETS on some later models, or ASR - Acceleration Slip Regulation), advanced independent suspension for stability.

Passive Safety Features:

Dual front airbags, side impact protection (in doors and B-pillars), reinforced body structure, crumple zones, seatbelt pre-tensioners.

💡 Technology Features

Audio System:

Factory premium audio systems, often Bose or Becker units, with CD changers and advanced (for the era) radio tuners.

Driver Aid Features:

Cruise control, potentially parking assist sensors (though less common than modern systems), dual-zone automatic climate control, power adjustable memory seats.

Suspension Systems:

Details on self-leveling suspension (SLS) or hydropneumatic suspension systems, which were common on these models.

Connectivity Options:

Limited by modern standards. Primarily focused on internal vehicle systems communication. CAN bus communication for module integration was a key feature introduced in this generation.

🔧 Maintenance

Oil Change Interval Typical:

Typically every 7,500 - 10,000 miles (12,000 - 16,000 km) or annually, whichever comes first, depending on driving conditions and oil type used. The manual will provide exact intervals for the specific engine.

Major Service Intervals:

Major services (e.g., spark plugs, transmission service, coolant flush) often recommended at intervals like 30,000, 60,000, or 100,000 miles. Specific intervals are detailed in the manual.

Engine Oil Spec Example:

MB 229.1 or MB 229.5 compliant synthetic oil, viscosity typically 0W-40, 5W-40, or 5W-30 depending on climate. Manual will specify exact API service categories and viscosity grades.

Transmission Fluid Spec Example:

For 722.6: MB 236.10 or MB 236.12 specification automatic transmission fluid (ATF). Manual will specify exact fluid type and capacity.

Coolant Spec Example:

Mercedes-Benz approved coolant (e.g., G05 based) or equivalent meeting MB-Approval 325.0 / 326.0, typically a 50/50 mix with distilled water.

Brake Fluid Spec:

DOT 3 or DOT 4 approved brake fluid, meeting Mercedes-Benz specification 331.0. Manual will confirm.

Common W140 Issues:

Coolant leaks (especially plastic components like coolant reservoir, valve cover gaskets), "biodegradable" wiring harness insulation degradation (leading to electrical issues), aging hydraulic suspension components (ABC on later models, or self-leveling suspension), MAF sensor issues, door lock actuators, window regulators, distributor caps/rotors on M119 engines.

Common W140 Electrical Issues:

Issues with SAM units (Signal Acquisition Module), ABS/ASR control modules, and power window/seat control modules can arise due to age and moisture ingress. Wiring harness issues are also prevalent.

📚 Vehicle History

Mercedes Benz Legacy:

Mercedes-Benz has a long-standing reputation for building flagship luxury sedans that set benchmarks in comfort, safety, and engineering. The S-Class is the embodiment of this heritage.

W140 Generation Era:

The W140 (introduced in 1991 for the 1992 model year) was a significant departure from its predecessor (W126), featuring a larger, more imposing design, advanced technology, and a focus on refinement and isolation from the road.

Production Years W140:

1991–1998 (for sedan), 1992–1999 (for coupe C140).

Manufacturing Location:

Primarily Sindelfingen, Germany.

🏆 Awards & Recognition

Industry Acclaim:

While specific awards for the 1997 model year might be scarce, the W140 generation was widely recognized for its engineering prowess, comfort, and technological advancements, solidifying Mercedes-Benz's position in the luxury automotive market.