🏷️ Basic Information

Make:

Mercedes-Benz

Model:

300 CD Turbo

Model Code:

W123 Coupe (Specific designation for this model)

Generation:

Second Generation W123 Coupe

Production Years Covered:

1982, 1983, 1984, 1985

Engine Code Series:

OM617 (Turbocharged Diesel)

👋 Introduction

Market Position:

The Mercedes-Benz 300 CD Turbo (W123 Coupe) represented a premium, yet relatively fuel-efficient, personal luxury coupe of the early 1980s, offering robust diesel performance with Mercedes-Benz's renowned build quality and engineering.

Competitive Analysis:

Competed against other European luxury coupes and higher-end American personal luxury cars, but stood out with its diesel engine offering, which was uncommon in the luxury segment at the time.

Key Features:

Turbocharged OM617 diesel engine for improved performance over naturally aspirated versions, elegant coupe styling, high-quality interior, renowned Mercedes-Benz durability and safety for its era, often equipped with advanced features like automatic climate control and power accessories.

📋 Manual Details

Coverage Areas:

1982 Mercedes-Benz 300 CD Turbo, 1983 Mercedes-Benz 300 CD Turbo, 1984 Mercedes-Benz 300 CD Turbo, 1985 Mercedes-Benz 300 CD Turbo

Page Count:

Estimated 1000+ pages (Typical for comprehensive factory service manuals of this era, though specific page count for this compilation not provided)

Manual Type:

Service and Repair Manual

Language:

English

Format:

PDF / WINRAR

📖 Manual Coverage

Systems Covered:

Engine Mechanical, Fuel System (Diesel Injection), Lubrication System, Cooling System, Air Intake System, Exhaust System, Ignition System (Glow Plugs), Clutch System, Manual Transmission, Automatic Transmission, Transfer Case (if applicable), Drive Shafts, Front Axle, Rear Axle, Suspension (Front and Rear, including Level Control/ADS), Steering System, Brake System (Hydraulic and Parking), Electrical System (Wiring Diagrams, Components), HVAC System (Heating, Ventilation, Air Conditioning), Body and Chassis, Interior Systems, Convertible Top (if applicable), Accessories

Procedures Included:

Disassembly, Inspection, Reassembly, Repair, Rebuilding, Adjustment, Troubleshooting, Diagnostics, Maintenance (scheduled and preventative), Component Replacement, Fluid Changes, Lubrication, Torque Specifications, Diagnostic Trouble Codes (if applicable), Wiring Diagrams

Technical Depth:

Comprehensive. Covers everything from basic fluid level checks and filter replacements to complete engine and transmission overhauls. Includes detailed diagnostic procedures and specifications for proper component function and repair. Expected to include specialized tool requirements.

📊 Manual Specifications

File Format:

PDF/WINRAR (Digital Download)

Print Quality:

High Resolution Digital Scans (assumed for a quality manual)

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Primary Engine:

3.0L Inline-5 Turbocharged Diesel (OM617.952)

Horsepower Approx:

123 hp @ 4,350 rpm (specifications can vary slightly)

Torque Approx:

183 lb-ft @ 2,400 rpm (specifications can vary slightly)

Fuel System:

Bosch Mechanical Diesel Injection Pump with Turbocharger

Engine Block Material:

Cast Iron

Cylinder Head Material:

Aluminum Alloy

Bore X Stroke:

90.9 mm x 92.4 mm

Compression Ratio:

21.0:1

Valvetrain:

Single Overhead Camshaft (SOHC), 2 Valves per Cylinder

🔧 Transmission

Standard:

4-speed Automatic Transmission (722.3 series)

Optional:

5-speed Manual Transmission (less common for US market 300 CD Turbo models)

Transmission Features:

Torque converter automatic with hydraulic control. Manual offers direct engagement and driver control.

📐 Dimensions

Length:

Approx. 187.1 inches (4752 mm)

Width:

Approx. 69.1 inches (1755 mm)

Height:

Approx. 54.3 inches (1380 mm)

Wheelbase:

Approx. 108.7 inches (2760 mm)

Curb Weight Approx:

3,400 - 3,600 lbs (1542 - 1633 kg), depending on options

🛡️ Safety Features

Safety Ratings:

No modern crash test ratings apply. For its era, Mercedes-Benz vehicles were known for robust construction and passive safety features.

Active Features:

Four-wheel disc brakes (front vented), power steering, independent front suspension.

Passive Features:

Reinforced passenger cell, energy-absorbing steering column, padded dashboard, front and rear crumple zones, seat belts (lap and shoulder belts in front).

💡 Technology Features

Infotainment System:

Basic factory radio with AM/FM, cassette player. Speaker system quality varies by trim.

Driver Assistance:

Limited by modern standards. Features like cruise control, power windows, and power locks were common. Optional features like ABS (Anti-lock Braking System) and self-leveling suspension (ADS) were available on some models, and this manual covers ADS.

Connectivity:

N/A (No factory connectivity features like Bluetooth or USB).

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles or 6-12 months, depending on driving conditions and oil quality used. Consult manual for specific recommendations.

Fuel Filter Replacement:

Recommended at intervals around 15,000-30,000 miles or annually. The manual will provide precise intervals.

Valve Adjustment Interval:

Typically around 20,000-30,000 miles or as needed based on engine noise. The manual details the procedure.

Engine Oil Specification:

API CD or higher, SAE 15W-40 or 10W-40 (consult manual for ambient temperature recommendations). Diesel engine oil is crucial.

Automatic Transmission Fluid Specification:

MB 236.1 specification Dexron II or equivalent. Manual will list exact spec and capacity.

Coolant Specification:

Ethylene glycol-based antifreeze, typically a 50/50 mix with distilled water. Check manual for Mercedes-specific approved types.

Brake Fluid Specification:

DOT 3 or DOT 4.

Known Issues:

Diesel injection pump timing drift, vacuum control system issues, climate control servo failures, potential for rust, rear axle boot leaks, aged rubber hoses and belts. The manual will guide diagnosis and repair.

📚 Vehicle History

Brand Heritage:

Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, durability, and innovation, dating back to the invention of the automobile.

Model Evolution:

The 300 CD Turbo is part of the W123 generation, known for its exceptional build quality and longevity. The Coupe (C123) variant offered a sportier, more stylish profile than the sedan and wagon versions. The introduction of the turbocharger on the diesel engine significantly improved performance.

Production Location:

West Germany

🏆 Awards & Recognition

Recognitions:

The W123 chassis as a whole received widespread acclaim for its durability and reliability, often referred to as 'over-engineered'. While specific awards for the 300 CD Turbo might not be individually documented, the model benefited from the Mercedes-Benz brand's strong reputation.