🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W123

Production Years Covered By Manual:

1981-1993

Chassis Code:

W123

Generation Name:

First Generation W123

👋 Introduction

Segment:

Premium Mid-Size Sedan/Wagon/Coupe

Competitors:

BMW 5 Series (E28), Audi 100, Volvo 240, Saab 900

Engineering Philosophy:

Over-engineered for durability, safety, and long-term reliability.

Durability Reputation:

The W123 is legendary for its robust build quality and ability to withstand high mileage with proper maintenance, making it a favorite for long-distance travel and classic car enthusiasts.

📋 Manual Details

Market Segment:

Luxury Compact/Mid-Size Sedan, Coupe, Wagon, and Limousine

Estimated Page Count:

Varies (Digital Manual - content density is high)

Type:

Comprehensive Service and Maintenance Manual

Language:

English (implied by context, may contain original manufacturer language elements)

Format:

Digital Download (PDF)

📖 Manual Coverage

Powertrain:

Engine (gasoline and diesel), Fuel System, Cooling System, Exhaust System, Transmission (manual and automatic)

Chassis:

Suspension (front and rear), Steering, Brakes (hydraulic, parking), Drivetrain

Electrical:

Ignition System, Lighting, Instrumentation, Power Accessories, Charging System, Starting System, Wiring Diagrams

Body:

Body Construction, Exterior Trim, Interior Trim, Climate Control, Doors, Windows, Seats

Comfort Systems:

Heating, Ventilation, and Air Conditioning (HVAC), power windows, central locking (often vacuum operated), seat adjustments.

Fuel System Gasoline:

Carburetor types, fuel pumps, fuel lines, K-Jetronic components (air flow meter, fuel distributor, injectors, warm-up regulator).

Fuel System Diesel:

Injection pumps (Bosch), glow plugs, injectors, fuel filters, lift pumps.

Maintenance:

Scheduled maintenance (oil changes, filter replacements, fluid checks), Inspections, Lubrication

Repair:

Component replacement, diagnostics, troubleshooting, assembly/disassembly of all major systems

Diagnostics:

Fault finding for mechanical and electrical issues, diagnostic charts, troubleshooting trees

Bodywork Repair:

Panel replacement, rust repair techniques, alignment procedures, glass installation.

Steering System:

Power steering pump, steering gear box, steering linkage, adjustment procedures.

Brake System:

Hydraulic system diagnostics, caliper overhaul, brake pad/shoe replacement, parking brake adjustment, ABS system troubleshooting (if equipped).

Depth:

Expert Level: Covers detailed diagnostic procedures, component-level repair, and specifications for advanced troubleshooting and rebuilds.

Wiring Diagrams:

Comprehensive electrical schematics for all major circuits, allowing for detailed troubleshooting of electrical faults.

📊 Manual Specifications

File Type:

PDF (Portable Document Format)

Searchability:

Likely text-searchable PDF, allowing for quick location of specific information.

Printability:

Printable sections or entire document (high-resolution scans/digital creation)

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

Region Specific:

Likely covers specifications and procedures relevant to major global markets where the W123 was sold.

⚙️ Engine Specifications

Engine Options:

M102 (2.0L Inline-4 Gasoline), M103 (2.6L Inline-6 Gasoline), M110 (2.8L Inline-6 Gasoline), OM615 (2.2L Inline-4 Diesel), OM616 (2.4L Inline-4 Diesel), OM617 (3.0L Inline-5 Diesel), OM601 (2.3L Inline-4 Diesel), OM602 (2.5L Inline-5 Diesel), OM603 (3.0L Inline-6 Diesel)

Horsepower Range:

70 hp (200D) to 185 hp (280E/CE/TE)

Fuel Delivery:

Carburetion (e.g., Solex, Zenith) and Bosch K-Jetronic Fuel Injection (CIS) for gasoline engines; Indirect Injection for diesel engines.

Diesel Engine Details:

OM615 (2.2L, 4cyl), OM616 (2.4L, 4cyl), OM617 (3.0L, 5cyl, naturally aspirated and turbocharged), OM601 (2.3L, 4cyl), OM602 (2.5L, 5cyl), OM603 (3.0L, 6cyl, turbocharged).

Gasoline Engine Details:

M115 (2.0L, 4cyl - early), M102 (2.0L/2.3L, 4cyl), M110 (2.8L, 6cyl, DOHC), M103 (2.6L, 6cyl, SOHC).

🔧 Transmission

Standard Transmission:

4-speed Manual (often standard on lower trims and diesel models)

Optional Transmission:

4-speed Automatic (e.g., 4G-TRONIC), 5-speed Manual (later models)

Transmission Features:

Robust construction, smooth shifting, power take-off capabilities on some models.

📐 Dimensions

Body Styles:

Sedan (W123), Coupe (C123), Estate/Wagon (S123), Limousine (V123)

Curb Weight Range:

Approximately 1300 kg to 1600 kg depending on body style and engine

🛡️ Safety Features

Crash Test History:

While formal ratings from modern bodies like NHTSA/IIHS were not standardized as today, the W123 was renowned for its robust safety cell, crumple zones, and high structural integrity, often outperforming contemporary vehicles.

Active Safety:

Four-wheel disc brakes (standard on many models, front discs standard on all), power steering, advanced suspension geometry.

Passive Safety:

Reinforced passenger compartment, safety steering column, padded dashboard, seat belts, optional airbags (late models).

💡 Technology Features

Infotainment Features:

Basic analog radio systems, often with cassette players in later models. Optional air conditioning.

Driver Assistance Features:

Power steering, cruise control (optional), Anti-lock Braking System (ABS) introduced on some later models.

Connectivity Features:

Minimal by modern standards; primarily focused on vehicle mechanics and comfort features rather than digital connectivity.

🔧 Maintenance

Oil Change Interval:

Typically 10,000-15,000 km (or annually), depending on engine and oil type used.

Engine Oil:

API SF/SG or ACEA A2, viscosity varies by temperature (e.g., 10W-40, 15W-40 for diesel; 5W-40, 10W-50 for gasoline).

Coolant:

Mercedes-Benz Specification 325.0 (Ethylene Glycol based, silicate-free, typically blue or green)

Brake Fluid:

DOT 3 or DOT 4 (non-silicone based)

Transmission Fluid Auto:

MB Specification 236.1 (e.g., Dexron III compatible fluid, although specific MB fluids are recommended)

Common Wear Items:

Vacuum leaks (affecting central locking, climate control, engine idle), rust (especially around wheel arches, door bottoms, sunroofs), aging rubber components (hoses, bushings), front suspension ball joints and bushings, diesel injector pump seals.

Diesel Engine Specifics:

Glow plug system maintenance, potential for injector pump leaks, overheating on older OM617 models if not maintained.

Gasoline Engine Specifics:

K-Jetronic fuel system tuning and maintenance, timing chain wear (M102/M103/M110), carburetor issues on non-injected models.

Engine Oil Capacity Range:

4.5L to 7.5L depending on engine variant

Oil Filter Part Number Example:

Mann-Filter W917/4, Bosch 0451103316 (Example for OM616/OM617)

📚 Vehicle History

Mercedes Benz Legacy:

Continuation of Mercedes-Benz's reputation for engineering excellence, durability, and luxury from the preceding W114/W115 range.

Evolution Overview:

Successor to the W114/W115 ('Stroke Eight') models, introducing more modern styling and advanced features. Refined over its production run with engine updates and feature enhancements.

Major Facelifts Updates:

1981: Introduction of new engine options (M102, OM601, OM602, OM603), updated interior features, improved safety. Later models received minor styling tweaks and improved aerodynamics.

Manufacturing Locations:

Germany (Sindelfingen), South Africa, and other global assembly plants.