Market Position:
The Mercedes-Benz 300D Turbo (W124) was positioned as a reliable, durable, and technologically advanced luxury diesel sedan. It appealed to buyers seeking fuel efficiency, long-term ownership value, and the prestige of the Mercedes-Benz brand.
Competitors:
Competed primarily against other European luxury sedans, although its diesel powertrain offered a unique selling proposition. Key competitors in the broader luxury segment included BMW (e.g., 524td), Audi, and Jaguar. Its diesel focus set it apart in many markets.
Key Features Vehicle:
Robust turbocharged OM603 diesel engine, advanced independent suspension, refined ride quality, high build quality, excellent safety features for its era, aerodynamic design, and long-term durability.
Key Features Manual:
Provides factory-level technical data, detailed diagnostic procedures, and comprehensive repair instructions, essential for maintaining and restoring these classic vehicles.
Years Covered:
1982, 1983, 1984, 1985, 1986, 1987
Page Count:
Likely over 1000 pages, typical for comprehensive factory-level workshop manuals.
Manual Type:
Service Repair Workshop Manual
Language:
English (Assumed based on typical market for such manuals)
Format:
Digital (PDF) is most common for aftermarket sales, but original might be printed.
Powertrain:
Engine (3.0L Turbo Diesel OM603.960), fuel injection system, turbocharger, exhaust system, cooling system, lubrication system, engine mechanicals (assembly/disassembly).
Transmission:
Automatic Transmission (e.g., 722.3 4-speed), clutch (if manual option existed, though less common for this specific diesel), driveshaft, differential.
Chassis:
Suspension (front and rear), steering system (power steering), braking system (hydraulic, ABS if equipped), wheel alignment.
Electrical System:
Wiring diagrams, charging system (alternator), starting system (starter), lighting, ignition (glow plugs), instrumentation, power accessories (windows, locks, etc.), fuse and relay locations.
Body And Interior:
Body panels, doors, windows, seats, HVAC system, interior trim, body sealing, corrosion protection.
Routine Maintenance:
Oil changes, filter replacements, fluid checks and top-offs, spark plug/glow plug replacement, belt inspections and tensioning.
Component Overhaul:
Engine rebuild, transmission overhaul, brake caliper rebuilding, power steering pump replacement.
Diagnostic Procedures:
Troubleshooting guides for common symptoms, fuel system diagnostics, electrical system testing, emissions system checks.
Component Replacement:
Step-by-step instructions for replacing major components like alternators, starters, radiators, fuel pumps, etc.
Special Tools:
Identification and usage of specialized Mercedes-Benz tools required for certain repairs.
Technical Depth:
Comprehensive, factory-level detail. Covers everything from basic maintenance to full engine and transmission rebuilds, including torque specifications, clearances, and diagnostic flowcharts.
File Format Quality:
Likely high-resolution scans or original digital files for clarity. Searchable text is highly desirable for digital formats.
Print Quality:
If printed, expect professional binding with durable pages designed for workshop use. High-quality paper to withstand grease and dirt.
Binding Type:
If printed: Spiral-bound or perfect-bound for easy page laying and durability. If digital: Searchable PDF.
Paper Type:
If printed: Heavy-duty, coated paper to resist wear and tear in a workshop environment. Likely a matte finish to reduce glare.
Engine Type:
Inline 6-cylinder, turbocharged, naturally aspirated diesel
Displacement:
2,999 cc (3.0 Liters)
Bore X Stroke:
87.0 mm x 84.0 mm
Compression Ratio:
21.0:1
Horsepower Net:
Approx. 125 hp @ 4,000 rpm (Varies slightly by market/year)
Torque Net:
Approx. 181 lb-ft (245 Nm) @ 2,400 rpm (Varies slightly by market/year)
0-60 Mph:
Approx. 12-13 seconds (depending on transmission and configuration)
Top Speed:
Approx. 115-120 mph (185-193 km/h)
Fuel System Type:
Bosch inline mechanical fuel injection system with turbocharger
Oil Capacity With Filter:
7.5 Liters (8 US Quarts)
Coolant Capacity:
Approx. 9.0 Liters (9.5 US Quarts)
Standard Transmission Type:
4-speed Automatic Transmission (Model 722.3)
Optional Transmission Type:
5-speed Manual Transmission (less common on the 300D Turbo models, but available in some markets/configurations)
Transmission Features:
Lock-up torque converter in top gear for improved efficiency and reduced heat. Hydraulic control system.
Automatic Transmission Fluid Spec:
MB 236.1 (e.g., Dexron II compatible, but specifically MB approved is recommended)
Automatic Transmission Fluid Capacity:
Approx. 7.5 Liters (requires refill during torque converter drain/fill)
Length:
Approx. 188.1 inches (4778 mm)
Width:
Approx. 69.1 inches (1755 mm)
Height:
Approx. 55.5 inches (1410 mm)
Wheelbase:
Approx. 109.5 inches (2780 mm)
Curb Weight:
Approx. 3,350 lbs (1520 kg)
Gross Vehicle Weight Rating:
Approx. 4,450 lbs (2020 kg)
Cargo Volume:
Approx. 16 cu ft (453 Liters)
Standard Tire Size:
195/65R15 (may vary by market and wheel option)
Wheel Bolt Pattern:
5x112 mm
Wheel Offset:
ET37 (typical for 15-inch wheels)
Era Safety Standards:
Designed to meet or exceed stringent safety standards of its time, including crumple zones and reinforced passenger compartment.
Active Safety Features:
Four-wheel disc brakes, power-assisted steering, optional Anti-lock Braking System (ABS) on later models.
Passive Safety Features:
Energy-absorbing steering column, dual-circuit hydraulic braking system, reinforced B-pillars, impact-absorbing interior materials.
Infotainment System:
Basic for its era: AM/FM radio, cassette player (often optional or dealer-installed), analog gauges for speed, RPM, fuel, oil pressure, coolant temperature. No digital displays or navigation.
Driver Assistance Features:
Optional ABS, power steering. No advanced electronic driver-assistance systems like traction control or stability control.
Connectivity Features:
Limited to basic antenna for radio. No Bluetooth or USB connectivity. Central locking and power accessories were considered advanced features.
Oil Change Interval:
Typically every 5,000-10,000 miles (8,000-16,000 km) or annually, whichever comes first, depending on driving conditions and oil used. The manual will provide specific recommendations.
Air Filter Replacement:
Every 15,000-30,000 miles (24,000-48,000 km) or as needed based on operating environment. Manual specifies exact intervals.
Fuel Filter Replacement:
Typically every 15,000-30,000 miles (24,000-48,000 km). Crucial for diesel engines. Manual will detail specific intervals.
Transmission Service:
Fluid and filter change recommended every 30,000-60,000 miles (48,000-96,000 km). Manual provides specific intervals and procedures.
Engine Oil Spec:
API CD or CE rated diesel engine oil, SAE 15W-40 or 10W-40 depending on climate. Refer to manual for precise MB approval specifications.
Coolant Spec:
Ethylene glycol based coolant meeting MB 325.0 specification (typically a 50/50 mix with distilled water).
Known Issues Diesel:
Injector pump issues, glow plug failures, vacuum leaks in the intake manifold, turbocharger wear, vacuum-actuated systems (e.g., central locking), potential for injector nozzle clogging, early signs of diesel particulate buildup.
Known Issues Chassis:
Ball joint wear, subframe mount deterioration, differential mounts, wheel bearing noise, potential for wiring harness degradation (insulation cracking).
Known Issues Electrical:
Instrument cluster issues, antenna motor failure, early ABS sensor failures, aging wiring insulation.
Brand Heritage:
Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, and durability, particularly in diesel technology.
Model Evolution W124:
The W124 was a significant evolution from the W123, featuring more advanced aerodynamics, a more sophisticated multi-link rear suspension, and increased emphasis on safety and driver comfort. The 300D Turbo represented Mercedes' push for more powerful and efficient diesel engines.
Production Years W124:
1984-1995 (sedan/coupe/wagon), with the 300D Turbo variants primarily in the earlier years of this range.
Manufacturing Location:
Primarily Germany (Sindelfingen, Bremen, etc.), with some assembly in other global locations.
Vehicle Awards Era:
While specific awards for the 300D Turbo might not be prominent, the W124 chassis as a whole was highly regarded for its engineering, build quality, and durability, often featuring in 'best cars' lists for their respective segments. It was a benchmark for its time.
Typical Reliability Reputation:
Generally considered extremely reliable and durable, especially the powertrain, when properly maintained. Often praised for longevity and low ownership costs over long distances due to fuel efficiency.
