🏷️ Basic Information Identification Make: Mercedes-Benz Model: 180d / 180Db / 180Dc Model Variants: 180d, 180Db, 180Dc Codes Chassis Code: W120 (primarily, but may extend to early W110 for certain shared components depending on exact year coverage) Engine Code Designation: OM621 👋 Introduction Market Position Vehicle Segment: Compact Executive / Luxury Sedan Target Audience: Discerning buyers seeking reliable, efficient, and prestigious compact transportation Competitive Analysis Key Competitors: BMW 1500/1600, Audi 72, Opel Rekord, Ford Taunus Key Features Brand Emphasis: Mercedes-Benz reputation for build quality, engineering, and longevity Engine Efficiency: Diesel engine providing excellent fuel economy for its era 📋 Manual Details Coverage Areas Documentation Type: Factory Service Repair Manual Market Coverage: Global (European and international specifications likely included) Page Count Estimated Pages: Hundreds (Specific page count not provided, but indicative of a comprehensive factory document) Manual Type Manual Format: Downloadable PDF Language Language: English (Typical for factory service manuals distributed internationally, may contain original German schematics) 📖 Manual Coverage Systems Covered Powertrain: Engine (OM621 diesel), Fuel System, Exhaust System, Clutch, Transmission (Manual), Drive Axle Chassis: Suspension (Front & Rear), Steering System, Brakes (Drum/Disc configurations depending on year), Wheels & Tires Electrical: 12V Electrical System, Lighting, Ignition, Starting System, Charging System, Instrumentation, Wiring Diagrams Body: Body Exterior, Body Interior, Doors, Windows, Seats, Bumpers, Body Seals Procedures Included Maintenance: Scheduled Maintenance Intervals, Lubrication, Fluid Changes, Filter Replacements, Inspections Repair: Engine Overhaul, Transmission Rebuild, Brake System Repair, Suspension Component Replacement, Electrical Component Diagnosis and Repair Troubleshooting: Diagnostic Procedures, Symptom-Based Troubleshooting Guides, Fault Code Interpretation (if applicable to the era) Technical Depth Depth Level: Comprehensive Factory-Level Diagnostics and Repair Diagnostic Tools: Special Tools and Equipment specified for repairs 📊 Manual Specifications File Format File Type: PDF Print Quality Printability: Printable (Entire manual or selected pages) Binding Type Binding Suggestion: Spiral or binder for individual page printing Paper Type Recommended Paper: Standard copy paper or heavier stock for durability ⚙️ Engine Specifications Primary Engine Engine Type: Inline 4-cylinder Diesel Engine Code: OM621 Displacement: 1.8 liters (1792 cc) Performance Horsepower Approx: 55-65 hp (depending on specific variant and tuning) Torque Approx: 95-105 lb-ft (depending on specific variant and tuning) Fuel System Injection Type: Indirect Injection (Pre-combustion chamber) with Bosch Inline Fuel Injection Pump Fuel Type: Diesel Fuel Cooling System Cooling Method: Water Cooled (Thermostatically controlled) Lubrication Oil Type Spec: API CD or equivalent Diesel engine oil (e.g., SAE 30 or 10W-30/10W-40 depending on climate) Oil Capacity Approx: 5.5 - 6.0 Liters (with filter) 🔧 Transmission Standard Transmission Type: 4-speed Manual Synchromesh (floor-mounted shifter) Optional Optional Transmission: 4-speed Automatic (less common) Features Clutch Type: Single Dry Plate, Diaphragm Spring Fluid Spec Manual Transmission Fluid: GL-4 SAE 90 Hypoid Gear Oil Fluid Capacity Manual Transmission Capacity: Approx. 1.5 - 1.8 Liters 📐 Dimensions Exterior Body Style: 4-door Sedan Wheelbase Approx: 2650 mm (104.3 in) Length Approx: 4470 mm (176 in) Width Approx: 1700 mm (66.9 in) Height Approx: 1450 mm (57.1 in) Weights Curb Weight Approx: 1200 - 1300 kg (2645 - 2866 lbs) Gross Vehicle Weight Rating Approx: 1700 kg (3748 lbs) Cargo Trunk Capacity Approx: 450 - 500 Liters (15.9 - 17.7 cu ft) 🛡️ Safety Features Ratings Crash Test Era: Pre-modern era; official ratings not comparable to current standards Active Features Braking System: Dual circuit hydraulic brakes, front discs (later models) and rear drums, or all-around drums on early models. Parking Brake: Mechanical parking brake operating on rear wheels. Passive Features Seatbelts: Lap belts standard, some later models may have offered optional front shoulder belts. Body Structure: Reinforced passenger safety cell (common Mercedes-Benz design principle) 💡 Technology Features Infotainment Radio System: Optional AM/FM radio (often a Becker unit), typically with limited speaker configuration. Dashboard Features: Mechanical gauges for speed, RPM, fuel, temperature, oil pressure; basic indicator lights. Driver Assistance Assistance Features: Minimal by modern standards. Focus on robust mechanicals rather than electronic aids. 🔧 Maintenance Service Intervals Oil Change Interval: Every 5,000 - 7,500 km (3,000 - 5,000 miles) or 6 months, whichever comes first. Air Filter Replacement: Every 15,000 - 20,000 km (9,000 - 12,000 miles) or annually. Fuel Filter Replacement: Every 10,000 - 15,000 km (6,000 - 9,000 miles). Fluid Specifications Coolant Type: Ethylene Glycol based Antifreeze / Coolant (e.g., Mercedes-Benz Spec 325.0 or equivalent) Coolant Capacity: Approx. 7.0 - 7.5 Liters Brake Fluid Type: DOT 3 or DOT 4 Hydraulic Brake Fluid (check manual for specific recommendation) Known Issues Diesel Injection: Wear on injector pump components, injector seal leaks, glow plug failures. Engine Cooling: Radiator leaks, thermostat sticking, water pump seal failure. Chassis Corrosion: Rust and corrosion, particularly in wheel arches, sills, and floor pans, due to age and environment. Suspension Wear: Bushings and ball joints can wear over time, leading to steering looseness and ride quality degradation. 📚 Vehicle History Brand Heritage Manufacturer Founding: 1926 (Merger of Daimler-Motoren-Gesellschaft and Benz &...