🏷️ Basic Information

Make:

Mercedes-Benz

Model:

S350

Year:

1995

Chassis Code:

W140

Engine Code Primary:

M104.990

👋 Introduction

Segment:

Full-size Luxury Sedan

Key Competitors 1995:

BMW 7 Series (E38), Lexus LS 400 (XF20), Audi A8 (D2), Jaguar XJ (XJ40)

Vehicle Positioning:

The W140 S-Class represented the pinnacle of Mercedes-Benz engineering and luxury in its era, known for its robust build quality, advanced technology, and exceptional ride comfort.

Manual Value Proposition:

Provides owners and technicians with the authoritative information needed to maintain and repair this complex luxury vehicle, ensuring longevity and optimal performance.

📋 Manual Details

Manual Type:

Service and Repair Manual

Language:

English

Format:

Digital (PDF likely, based on description)

Estimated Page Count:

Comprehensive, likely over 1000 pages (typical for this era's Mercedes service manuals)

📖 Manual Coverage

Engine Mechanics:

Engine disassembly, assembly, overhaul, timing, lubrication, cooling systems

Fuel System:

Fuel injection (Bosch LH-Jetronic), fuel pump, injectors, pressure regulator

Ignition System:

Ignition control module, coil packs, spark plugs, wiring

Transmission Automatic:

722.6xx (5-speed automatic) - diagnostics, fluid changes, overhaul procedures

Drivetrain:

Driveshafts, differentials, axles, CV joints

Suspension:

Front and rear suspension components, shock absorbers, springs, control arms, bushings

Steering:

Power steering system, steering gear, linkages, troubleshooting

Brakes:

Hydraulic system, ABS (Anti-lock Braking System), brake pads, rotors, calipers, lines, bleeding procedures

Electrical System:

Battery, alternator, starter, lighting, fuses, relays, wiring diagrams

Climate Control:

HVAC system, A/C compressor, evaporator, condenser, blower motor, climate control module

Body:

Body panels, doors, latches, windows, sunroof, exterior trim

Interior:

Seats, dashboard, trim panels, interior lighting, sound insulation

Diagnostics:

Troubleshooting charts, diagnostic trouble codes (DTCs) for various ECUs

Maintenance:

Oil changes, filter replacements, fluid checks and flushes, spark plug replacement, belt inspection/replacement

Repair:

Component removal and installation, sub-assembly repair, full rebuild procedures

Troubleshooting:

System-specific diagnostic trees, common fault identification and correction

Adjustments:

Valve adjustments (if applicable to M104), idle speed adjustments, alignment procedures

Depth Level:

Comprehensive, from basic maintenance to full engine and transmission rebuilds, including electrical system diagnostics and wiring diagrams.

📊 Manual Specifications

Digital Format:

Likely PDF, optimized for searchability and printing.

Output Quality:

High resolution for clear text and diagrams.

Physical Format If Applicable:

N/A (Digital)

Digital Features:

Searchable text, bookmark functionality, clickable links for navigation.

⚙️ Engine Specifications

Engine Type:

3.5L Inline-6 Cylinder

Engine Code:

M104.990

Displacement:

3495 cc (3.5 Liters)

Bore X Stroke:

92.0 mm x 86.6 mm

Compression Ratio:

10.0:1

Horsepower:

247 hp @ 5500 rpm (approx.)

Torque:

340 Nm (251 lb-ft) @ 3750 rpm (approx.)

Fuel Delivery:

Bosch LH-Jetronic Electronic Fuel Injection (EFI)

Fuel Type:

Unleaded Premium Gasoline (91+ Octane)

Emission Control:

Three-way catalytic converter, secondary air injection (model dependent)

🔧 Transmission

Transmission Type:

5-Speed Automatic

Transmission Model:

722.6xx (e.g., 722.603)

Optional Transmission:

N/A for S350 in this year, 4-speed automatic was common on earlier models or lower trims.

Transmission Features:

Electronic control, multiple shift modes (e.g., Comfort/Sport), torque converter lock-up.

📐 Dimensions

Wheelbase:

3,135 mm (123.4 inches)

Length:

5,163 mm (203.3 inches)

Width:

1,886 mm (74.3 inches)

Height:

1,487 mm (58.5 inches)

Curb Weight:

Approx. 1,960 kg (4,321 lbs)

🛡️ Safety Features

NHTSA Rating:

Not typically rated by NHTSA in the same way as modern vehicles; manufacturer's internal safety standards were very high.

ABS:

Standard (Bosch 2.0 ABS System)

Traction Control:

ASR (Acceleration Slip Regulation) standard.

Airbags:

Driver and front passenger airbags, side airbags (optional on some models).

Seatbelts:

Pretensioning seatbelts, load limiters.

Body Construction:

High-strength steel safety cell, crumple zones.

💡 Technology Features

Audio System:

Original Becker or Bose premium sound systems, cassette or CD player.

Navigation:

Optional factory navigation system (often DVD-based on later models).

Cruise Control:

Standard cruise control with electronic throttle control.

Parking Sensors:

Optional PARKTRONIC parking assist system.

Phone Integration:

Early integrated cellular phone systems (often analog).

Automatic Climate Control:

Dual-zone automatic climate control (THERMOTRONIC).

Rain Sensing Wipers:

Optional rain-sensing wiper system.

Power Seats:

Multi-way power adjustable front seats with memory function.

🔧 Maintenance

Oil Change Interval:

Typically every 7,500 - 10,000 miles (12,000 - 16,000 km) or annually, depending on driving conditions and oil type. Refer to manual for specific 'Service A/B' intervals.

Transmission Fluid Change:

Recommended every 40,000 - 60,000 miles (64,000 - 96,000 km). Use only MB-approved fluid (e.g., ATF 3403-M115).

Coolant Flush:

Typically every 2-3 years or 30,000-50,000 miles. Use MB-approved coolant concentrate.

Engine Oil Specification:

API SJ or higher, SAE 0W-40 or 5W-40 synthetic recommended. Consult manual for exact MB approval (e.g., MB 229.1, 229.3).

Coolant Specification:

Mercedes-Benz Approved Antifreeze/Coolant (e.g., G05 based).

Brake Fluid Specification:

DOT 3 or DOT 4.

Power Steering Fluid:

Mercedes-Benz Power Steering Fluid (MB Part No. A0009898803 or equivalent).

Wiring Harness Degradation:

Insulation breakdown on engine wiring harnesses (especially Biodegradable insulation) leading to sensor faults and misfires.

ABS Esp Sensors:

Failure of ABS wheel speed sensors and ESP module issues.

Mass Air Flow Sensor:

Failure of the MAF sensor can cause poor performance and idle issues.

Headliner Sagging:

Common interior issue where the fabric detaches from the backing board.

Door Lock Actuators:

Vacuum operated door locks can develop leaks or faulty actuators.

Climate Control Actuators:

Faulty blend door actuators can cause incorrect air distribution.

Water Pump Leaks:

Water pump seals can degrade over time.

Head Gasket Leaks:

While the M104 is generally robust, head gasket issues can occur, particularly if the engine has been overheated.

📚 Vehicle History

Mercedes Benz Legacy:

Mercedes-Benz has a long history of producing luxury, performance, and technologically advanced vehicles, with the S-Class line being its flagship sedan for decades.

W140 Generation Details:

The W140 generation (1991-1998) succeeded the W126 S-Class. It was larger, more technologically advanced, and significantly more complex, often referred to as the 'Sonderklasse' (Special Class).

S350 Positioning W140:

The S350 was an entry-level engine option for the W140 chassis in many markets, offering a balance of performance and efficiency compared to the larger V8 and V12 engines, but still providing a refined driving experience.

W140 Production Years:

1991-1998

Manufacturing Location:

Sindelfingen, Germany

🏆 Awards & Recognition

Industry Recognition:

While specific awards for the 1995 S350 model may not be individually cataloged, the W140 S-Class generation generally received acclaim for its technological advancements, safety, and luxury, solidifying Mercedes-Benz's reputation in the ultra-luxury segment.