Model Years Covered:
1991-1999
Engine Codes:
M104 (2.8L, 3.2L I6), M119 (4.2L, 5.0L V8), M120 (6.0L V12)
Transmission Codes:
4G-TRONIC (4-speed automatic), 5G-TRONIC (5-speed automatic)
Segment:
Full-size luxury sedan
Positioning:
Flagship model, pinnacle of automotive engineering and luxury for its era
Competitors:
BMW 7 Series (E32/E38), Lexus LS400, Cadillac DeVille/Seville, Rolls-Royce Silver Spirit/Silver Spur
Luxury Features:
Double-pane glass, self-leveling rear suspension, advanced climate control, optional heated/ventilated seats, optional power rear seats, soft-close doors
Engineering Highlights:
Sophisticated chassis design, powerful and smooth engine options, advanced electronics for its time
Target Audience:
Owners, independent repair shops, DIY enthusiasts
Value Statement:
Provides access to factory-level repair and maintenance information, crucial for maintaining the complex systems of the W140
Coverage:
All mechanical, electrical, body, and diagnostic systems
Estimated Page Count:
Hundreds (detailed)
Type:
Factory Service and Repair Workshop Manual
Device Compatibility:
Windows, MAC, Tablets, Smartphones
Usage License:
Lifetime usage, no expiry, multi-device compatible
Powertrain:
Engine mechanical, fuel system, ignition system, cooling system, exhaust system, engine control systems (ME, LH-SFI, etc.)
Drivetrain:
Transmission (automatic), driveline components, differential, axles
Chassis:
Suspension (front and rear, including self-leveling rear suspension), steering system, braking system (ABS, ASR)
Electrical:
Vehicle electrical system, battery, charging system, starter, lighting, power windows, power seats, power mirrors, climate control electronics, central locking, infotainment systems, SRS (airbag) system
Body:
Body exterior, interior trim, doors, glass, seals, body repair
HVAC:
Automatic climate control, heating, ventilation, air conditioning system (including refrigerant handling)
Maintenance:
Scheduled maintenance, oil changes, filter replacements, fluid checks and changes, spark plug replacement, belt inspection and replacement
Diagnostics:
Troubleshooting guides, symptom-based diagnostics, fault code interpretation (OBD-I, specific Mercedes diagnostic protocols)
Repair:
Engine component removal/installation (cylinder heads, pistons, crankshaft), transmission overhaul, brake component replacement, suspension linkage replacement, electrical component repair/replacement
Installation:
Component replacement and installation procedures
Special Tools:
Identification and usage of specialized Mercedes-Benz tools
Depth:
Comprehensive, covering from basic maintenance to advanced engine and electrical system overhauls
Documentation Quality:
Step-by-step instructions, detailed photos, exploded diagrams
Engine Options:
3.2L Inline-6 (M104.990, M104.992), 4.2L V8 (M119.960), 5.0L V8 (M119.970), 6.0L V12 (M120.980, M120.982)
Inline 6 Power:
Approx. 228-279 hp (depending on variant and market)
V8 Power:
Approx. 275-322 hp (depending on variant and market)
V12 Power:
Approx. 389-408 hp (depending on variant and market)
Injection Type:
Bosch LH-Jetronic or ME-Electronic Fuel Injection (depending on engine and year)
Fuel Type:
Premium Unleaded Gasoline (91+ octane)
Coolant Type:
Mercedes-Benz approved antifreeze/coolant concentrate (e.g., G48)
ECU Type:
Various, depending on engine and model year (e.g., HFM, ME 2.0, ME 2.8 for later models)
Transmission Options:
4-speed automatic (4G-TRONIC), 5-speed automatic (5G-TRONIC)
Gear Ratios 5G Tronic:
Variable by model, refer to manual for specific ratios (e.g., 3.93/2.40/1.57/1.00/0.73 for one variant)
Electronic Control:
Electronically controlled transmission with comfort and sport modes
Transmission Fluid Type:
MB 236.1, MB 236.6, or MB 236.14 (depending on specific transmission and year; manual is definitive)
Wheelbase Sedan:
3,139 mm (123.6 in)
Length Sedan:
5,103 mm (200.9 in)
Width:
1,886 mm (74.3 in)
Height Sedan:
1,487 mm (58.5 in)
Curb Weight:
Varies by model, typically 1,900-2,300 kg (4,189-5,070 lbs)
Gross Vehicle Weight Rating:
Varies by model, typically around 2,500-2,800 kg
Wheel Bolt Pattern:
5x112
Standard Tire Sizes:
215/65 R16, 235/60 R16, 235/50 R17 (depending on model and year)
Crash Test Ratings:
N/A (Modern standardized ratings not prevalent during its production era)
Airbags:
Driver and passenger airbags (SRS) standard; optional side airbags in later models
Seatbelts:
Pre-tensioning seatbelts, automatic belt height adjustment
Body Construction:
High-strength steel safety cage
ABS:
Anti-lock Braking System (ABS) standard
Asr:
Anti-Slip Regulation (ASR) / Traction Control standard or optional
Esp:
Electronic Stability Program (ESP) not widely available on W140, but could be integrated into later ABS/ASR systems on some models
Audio System:
Factory premium sound systems (e.g., Becker/Bose), often with cassette player and optional CD changer.
Navigation:
Optional factory navigation system (COMAND predecessor) available on later models.
Cruise Control:
Standard cruise control with electronic regulation.
Parking Assistance:
Optional rear parking sensors (often referred to as Parktronic or similar, though early versions)
Phone Integration:
Optional integrated car phone systems.
Key System:
Infrared remote key with central locking, although early models may have used a simpler key fob.
Lighting Features:
Automatic headlight leveling, front and rear fog lights, puddle lights in doors.
Oil Change Interval:
Typically every 10,000-15,000 km or 1 year, depending on driving conditions and oil used (refer to manual for specific interval and service code)
Major Service Interval:
Refer to manual for 'Service A', 'Service B', etc., which occur at increasing kilometer/time intervals (e.g., 30,000 km, 60,000 km, 100,000 km)
Engine Oil Capacity:
Approx. 7.5-8.5 liters (depending on engine)
Engine Oil Type:
MB 229.1, MB 229.3, or MB 229.5 approved synthetic oil (e.g., 0W-40, 5W-40, 5W-30 depending on temperature and specific engine; manual is definitive)
Coolant Capacity:
Approx. 10-12 liters (depending on engine)
Brake Fluid Type:
DOT 4, preferably low viscosity (e.g., MB 331.0)
Wiring Harness:
Degradation of insulation on engine wiring harnesses (especially biodegradable coatings) leading to electrical faults.
Cooling System:
Plastic coolant reservoir cracks, water pump leaks, radiator leaks, thermostat housing leaks.
Electronics:
Failure of window regulators, central locking system issues, climate control module failures, MAS (Mass Airflow Sensor) issues, EZS (Electronic Ignition Switch) problems.
Suspension:
Wear in self-leveling suspension components (rear shocks), front ball joints, and bushings.
Rust:
Corrosion can occur in common areas like wheel arches, door bottoms, and underbody.
Brand Legacy:
Mercedes-Benz has a long-standing reputation for luxury, engineering, and safety, established over decades.
Predecessor:
W126 S-Class
Production Period:
1991-1998 (marketed as '91-'99 models)
Manufacturing Locations:
Sindelfingen, Germany
Facelift Year:
1994 (major revisions including engine updates, 5G-TRONIC introduction, exterior styling tweaks)
Historical Recognition:
While specific awards for the W140 itself are not as commonly cited as later models, it was widely recognized by automotive press for its engineering, luxury, and comfort.
Reliability Perception:
Perceived as highly reliable when maintained meticulously, though complex systems can lead to costly repairs if neglected.
