Positioning:
Premium luxury sedan, representing the pinnacle of Mercedes-Benz engineering for its era
Competitors:
BMW 7 Series (E32), Lexus LS 400, Audi V8 Quattro
Distinguishing Features:
Solid build quality, advanced engineering, comfortable ride, sophisticated design (at the time)
Era Significance:
Marked a significant redesign and technological advancement for Mercedes-Benz sedans
Engine:
Detailed diagnostics, repair, and overhaul of M104 inline-6 engine
Transmission:
Service and repair procedures for 4-speed automatic transmission (722.4)
Brakes:
Front and rear brake system diagnostics, repair, and component replacement
Suspension:
Front and rear suspension systems, including springs, shocks, bushings, and alignment
Steering:
Power steering system diagnostics and repair
Electrical System:
Comprehensive wiring diagrams, component testing, and troubleshooting for all electrical systems
Climate Control:
Air conditioning and heating system service and repair
Fuel System:
Fuel injection system (Bosch KE-Jetronic) diagnostics, components, and repair
Exhaust System:
Exhaust system inspection, repair, and component replacement
Cooling System:
Radiator, water pump, thermostat, and coolant system service
Body And Frame:
Body panel repair, door mechanisms, and chassis components
Interior Trim:
Interior component removal and installation
Lighting:
Headlights, taillights, and interior lighting systems
Emission Control:
Emission control systems and diagnosis
Maintenance:
Scheduled maintenance, oil changes, filter replacements, fluid checks
Diagnostics:
Troubleshooting guides, fault code interpretation, component testing procedures
Repair:
Step-by-step repair instructions for all major vehicle systems
Overhaul:
Detailed procedures for engine and transmission overhauls
Adjustment:
Adjustments for brakes, steering, and engine components
Calibration:
Calibration procedures for relevant electronic systems (where applicable)
Depth:
Comprehensive, covering from basic maintenance to advanced engine and transmission rebuilds
Engine Type:
3.0L DOHC Inline 6-Cylinder
Horsepower:
217 hp @ 5700 rpm (approx.)
Torque:
268 lb-ft @ 3700 rpm (approx.)
Injection System:
Bosch KE-Jetronic Electronic Fuel Injection
Fuel Type:
Unleaded Premium Gasoline (91+ octane)
Ignition System:
Electronic Ignition (EZL)
Block Material:
Aluminum Alloy
Head Material:
Aluminum Alloy
Bore X Stroke:
88.5 mm x 80.2 mm
Compression Ratio:
10.0:1
Crash Test Information:
NHTSA ratings not directly comparable to modern standards; generally robust construction
ABS:
Standard Anti-lock Braking System (ABS)
Airbags:
Driver's side airbag standard
Seatbelts:
Front and rear seatbelts with pretensioners
Chassis Construction:
Reinforced body structure
Oil Change Interval:
Every 7,500 - 10,000 miles or 12 months, whichever comes first (consult manual for specific interval)
Transmission Service:
Fluid and filter change recommended every 40,000 - 60,000 miles
Engine Oil:
API SG/SH, ACEA A2/A3, MB 229.1 (e.g., 10W-40, 15W-40 depending on climate)
Coolant:
MB 325.0 Coolant (Glycol-based) with distilled water (50/50 mix)
Brake Fluid:
DOT 3 or DOT 4
Power Steering Fluid:
MB 236.3 Hydraulic Fluid or Dexron II
Common Problems:
Vacuum line issues (self-leveling suspension, door locks), EIS (Electronic Ignition Switch) failures, biodegrading wiring insulation (older harnesses), radiator support bushings, fuel distributor leaks.
Maintenance Tips:
Regularly inspect vacuum lines, maintain cooling system, and address any oil leaks promptly.
Mercedes Benz Legacy:
Long-standing reputation for luxury, engineering, and durability
W140 Introduction:
Introduced in 1991 as a successor to the W126 S-Class, representing a significant technological leap.
W140 Design Philosophy:
Emphasis on technological innovation, safety, comfort, and a more imposing road presence.
Production Years:
1991-1998 (W140 generation)
Assembly Location:
Sindelfingen, Germany
