Positioning:
Luxury German sedan known for its engineering prowess and comfort, targeting the executive market
Competitors 1991:
BMW 7 Series (E32), Audi V8 Quattro, Lexus LS 400, Jaguar XJ
Diesel Performance:
Torque-rich turbodiesel engine offering a blend of performance and efficiency for its class
Luxurious Appointments:
High-quality interior materials, advanced comfort features, and sophisticated design
Engineering Excellence:
Reputation for robust construction and advanced automotive technology
General Coverage:
Comprehensive repair, maintenance, rebuilding, refurbishment, and restoration
Diagnostic Coverage:
All diagnostic and repair procedures in great detail
Estimated Pages:
High (typically 1000+ pages for factory-level manuals)
Type:
Service and Repair Manual
Format:
Digital (likely PDF), potentially printed
Powertrain:
Engine (diesel, turbo), fuel injection, exhaust, cooling, lubrication, transmission (automatic)
Chassis:
Suspension (independent front/rear, self-leveling rear suspension), steering, brakes (ABS), wheels, tires
Electrical:
Wiring diagrams, lighting, ignition, charging system, starting system, instrumentation, comfort systems, power accessories
Body:
Body construction, exterior trim, interior trim, climate control, doors, windows, seats
Maintenance:
Scheduled maintenance, oil changes, filter replacements, fluid checks and changes, inspections
Repair:
Engine overhauls, transmission repairs, brake system repairs, suspension component replacement, electrical component diagnosis and repair
Troubleshooting:
Diagnostic procedures, fault code interpretation (if applicable), common problem diagnosis
Depth:
Factory-level, including detailed disassembly/assembly, specifications, tolerances, and torque values
Digital Searchability:
High (if PDF with OCR)
Printable:
Yes (standard for service manuals)
Illustrations:
High quality, detailed diagrams and photographs
Text Clarity:
Excellent, professional typesetting
Binding:
N/A (for digital), or professional binding (for print)
Paper:
N/A (for digital), or high-quality, durable paper (for print)
Engine Type:
Inline 6-cylinder Turbocharged Diesel
Displacement:
3.5 Liters (3449 cc)
Bore X Stroke:
91.4 mm x 110.0 mm
Compression Ratio:
21.0:1
Horsepower Ps:
148-150 PS @ 4000 rpm (approximate)
Torque Lb Ft:
236-250 lb-ft @ 2400 rpm (approximate)
Injection System:
Bosch VE Rotary Injection Pump with Turbocharging
Cooling System:
Water-cooled, pressurized system
Crash Safety Era Considerations:
Designed to 1990s safety standards, advanced for its time but not comparable to modern NCAP ratings
ABS:
Standard Anti-lock Braking System (ABS)
Airbags:
Driver airbag standard, passenger airbag likely optional or introduced later in the W140 lifecycle
Seatbelts:
Pre-tensioning front seatbelts
Body Construction:
High-strength steel safety cage
Audio System:
Premium Becker or Blaupunkt cassette-based audio systems, often with CD changer pre-wiring
Climate Control:
Automatic climate control with dual-zone capability
Cruise Control:
Standard cruise control
Parking Assistance:
Parking Assist System (PAS) - optional, typically rear parking sensors were not common in 1991
Connectivity Features:
Limited by 1991 standards; no integrated Bluetooth or smartphone connectivity
Oil Change Interval Km:
Typically 7,500 - 10,000 km (or annually), consult manual for exact recommendations
Air Filter Replacement Km:
30,000 - 40,000 km (or as needed)
Fuel Filter Replacement Km:
20,000 - 30,000 km (crucial for diesel engines)
Coolant Change Interval Years:
Every 2-4 years
Engine Oil Specification:
MB 229.1 or equivalent API CG-4/CF spec, SAE 10W-40 or 15W-40 (viscosity dependent on climate)
Engine Oil Capacity Liters:
Approx. 7.5 Liters
Transmission Fluid Type:
ATF DEXRON II/III or MB 236.6 specification
Coolant Type:
Mercedes-Benz Coolant/Antifreeze Concentrate (e.g., G05 or G48, mixed 50/50 with distilled water)
Diesel Specific Issues:
Glow plug system failure, injection pump issues, potential turbocharger wear, carbon buildup in intake manifold
General W140 Issues:
Vacuum system leaks (affecting door locks, HVAC), electrical gremlins, biodegradable wiring harness degradation (later models, but worth noting), suspension self-leveling issues
Mercedes Benz Reputation:
Long-standing reputation for engineering excellence, luxury, and durability
W140 Introduction:
The W140 S-Class was introduced in 1991 as the successor to the W126 S-Class, representing a significant leap in size, technology, and luxury.
350 Sd Turbo Significance:
The 'SD' designation signified a 'Saugdiesel' (naturally aspirated diesel) initially, but the 'Turbo' suffix clearly denotes the turbodiesel variant, a move towards more powerful and efficient diesel engines for Mercedes-Benz luxury cars.
Production Period W140:
1991-1998
Manufacturing Location:
Germany
