🏷️ Basic Information Identification Make: Mercedes-Benz Model: Typ-123 Model Variant: 300D Turbodiesel Sedan Production Years Covered: 1977-1985 Chassis Code: W123 Codes Engine Code: OM617 (Turbocharged Inline-5 Diesel) 👋 Introduction Market Position Positioning: Essential technical resource for owners and mechanics of the Mercedes-Benz W123 300D Turbodiesel Sedan. Competitive Analysis Value Proposition: Provides professional-level repair and maintenance information, comparable to factory service manuals, at a fraction of the cost and with instant digital access. Key Features Content Highlight: Covers the entirety of vehicle systems and repair procedures, from basic maintenance to complex overhauls, with detailed illustrations. 📋 Manual Details Coverage Areas Scope: Comprehensive repair, maintenance, rebuilding, refurbishment, and restoration Diagnostic Procedures: Detailed diagnostic and repair procedures Technical Documentation: Information used by professional technicians and mechanics Page Count Estimated Pages: N/A (Digital Download) Manual Type Type: Workshop Repair Service Manual Language Language: English Format Digital Format: PDF Downloadable: Yes Compatibility: All Versions of Windows, Mac, Linux 📖 Manual Coverage Systems Covered Engine Mechanical: Yes Engine Lubrication System: Yes Engine Cooling System: Yes Engine Control System: Yes Fuel System: Yes Exhaust System: Yes Clutch: Yes Manual Transaxle: Yes Automatic Transaxle: Yes Front Axle: Yes Rear Axle: Yes Front Suspension: Yes Rear Suspension: Yes Road Wheels And Tyres: Yes Brake System: Yes Parking Brake System: Yes Brake Control System: Yes Power Steering System: Yes Steering System: Yes Seat Belts: Yes Supplemental Restraint System Srs: Yes Body Lock And Security System: Yes Glasses Window System And Mirrors: Yes Roof: Yes Exterior And Interior: Yes Instrumental Panel: Yes Seat: Yes Air Conditioner System: Yes Wiring Diagrams: Yes Starting And Charging System: Yes Lighting System: Yes Driver Information System: Yes Wiper Washer And Horn: Yes Body Control System: Yes Lan System: Yes Audio Visual Navigation And Telephone System: Yes Auto Cruise Control System: Yes Power Supply Ground And Circuit Elements: Yes Maintenance Procedures: Yes Procedures Included Maintenance: Yes Troubleshooting: Yes Repair: Yes Rebuilding: Yes Refurbishment: Yes Restoration: Yes Technical Depth Depth: Detailed diagnostic and repair procedures covering all aspects from A-Z Illustrations: High Quality Photos, Illustrations And Diagrams Completeness: 100% Complete and Intact, No Missing/Corrupt Pages/Sections 📊 Manual Specifications File Format Format: PDF Searchable: Yes (Implied by PDF format for digital download) Print Quality Quality: High Quality Digital Content Binding Type Type: N/A (Digital Download) Paper Type Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Inline 5-Cylinder Diesel with Turbocharger Engine Code: OM617.952 Displacement: 3.0 Liters (2998 cc) Performance Horsepower Net Est: 125 hp @ 4350 rpm Torque Net Est: 184 lb-ft (250 Nm) @ 2400 rpm Fuel System Fuel Delivery: Bosch Inline Fuel Injection Pump with Turbocharger Recommended Fuel: Diesel Fuel (refer to manual for specific grade recommendations) 🔧 Transmission Standard Type: 4-Speed Automatic (4G-Tronic) Optional Type: 4-Speed Manual Features Transmission Fluid Type: MB 236.1 or equivalent (specific viscosity may vary, consult manual) 📐 Dimensions Exterior Length: 188.2 inches (4780 mm) Width: 69.5 inches (1765 mm) Height: 56.1 inches (1425 mm) Weights Curb Weight Est: 3400-3600 lbs (1542-1633 kg) 🛡️ Safety Features Passive Features Seatbelts: Standard seat belts Body Construction: Reinforced safety cage, crumple zones 💡 Technology Features Infotainment Features: Basic AM/FM radio, optional cassette player. Emphasis on mechanical and functional systems rather than advanced electronics. Driver Assistance Features: Power steering, optional cruise control (auto-cruise control system covered in manual). 🔧 Maintenance Service Intervals Oil Change Interval Engine: Typically 3,000-5,000 miles or 6 months (refer to manual for specific recommendation based on driving conditions). Fuel Filter Replacement: Recommended every 15,000-20,000 miles (consult manual). Air Filter Replacement: Recommended every 15,000-20,000 miles or as needed based on driving environment (consult manual). Fluid Specifications Engine Oil Type: API CD or better, SAE 15W-40 or 10W-30 depending on climate (consult manual for precise specification). Coolant Type: Ethylene glycol based, 50/50 mix with distilled water (refer to manual for specific Mercedes-Benz specification). Known Issues Common Wear Items: Vacuum leak issues (central locking, climate control), injector pump seals, glow plug system, valve seals, and potential rust in certain areas. Diesel Specific Concerns: Glow plug reliability, injection pump timing, injector health, and fuel system cleanliness. 📚 Vehicle History Brand Heritage Heritage: Mercedes-Benz is renowned for its engineering excellence, durability, and luxury, with a long history of producing robust diesel vehicles. Model Evolution W123 Introduction: The W123 generation replaced the W114/W115 and was produced from 1975 to 1986. The 300D Turbodiesel variant, introduced later in the W123's lifecycle, brought enhanced performance to the robust diesel platform. Production Production Period: 1975-1986 (W123 platform), 1977-1985 specifically for 300D Turbodiesel Sedan in this manual's coverage. 🏆 Awards & Recognition Recognitions Reputation: The W123 series is widely regarded as one of the most durable and reliable Mercedes-Benz models ever produced, often called 'the tank' for its build quality and longevity. Ratings Reliability Perception: Exceptional, especially for the diesel variants, due to robust engineering and simple, durable...