Target Audience:
Owners of Mercedes-Benz 300 D Turbo (W123) models from 1982-1985 seeking to perform maintenance, repairs, and diagnostics.
Value Proposition:
Offers comprehensive, factory-level repair information in an accessible digital format, saving owners the cost of dealership labor and providing detailed guidance.
Delivery Method:
Instant download, eliminating shipping costs and wait times.
Searchability And Bookmarking:
Enhanced usability through complete bookmarking and full text search functionality.
Engine Systems:
Diesel injection system, fuel delivery, cooling system, lubrication system, intake and exhaust systems, engine mounts, V-belts, poly V-belts, oxygen sensor, spark plugs (though primarily diesel, the mention of spark plugs is unusual but included in the description).
Transmission Systems:
Manual transmission (oil change, level check/correction), Automatic transmission (fluid and filter change, level check/correction), Transfer case (fluid change, level check/correction).
Drivetrain Systems:
Front axle (oil level check/correction, ball joint inspection), Rear axle (oil change, oil level check/correction, mount adjustment), Drive shaft flexible coupling inspection.
Braking Systems:
Brake fluid level check, brake line inspection, brake pad and disk thickness inspection, brake disk cleaning, parking brake adjustment and testing, brake fluid replacement.
Systems:
Power steering fluid level check, steering play check, steering bolt retightening, suspension and body structure inspection, self-leveling suspension inspection, Level Control (ADS, ASD, 4MATIC) fluid level.
Systems:
Battery fluid level check, warning and indicator lamp checks, headlamp and exterior lamp inspection.
Systems:
Body structure inspection, water leakage and corrosion inspection, wheel inspection and rotation, tire inspection and pressure correction, wheel bolt tightening, throttle linkage inspection/lubrication, door hinge lubrication, door lock lubrication, sunroof rail cleaning/greasing, soft top locking tab check, hood lubrication, lower noise encapsulation panel removal/installation, body paint damage inspection.
Systems:
Hydraulic top fluid level check, windshield washer fluid level check, HVAC system (dust filter replacement, active charcoal filter replacement, recirculating air filter replacement), antenna mast cleaning, cassette deck tone head cleaning.
Maintenance:
Engine oil and filter change, valve clearance adjustment/checking, idle speed adjustment/checking, injection timing adjustment/checking, fuel filter/prefilter replacement, air filter cleaning/replacement, V-belt and poly V-belt condition check, coolant level and antifreeze protection check, coolant replacement, engine stop adjustment, engine mount bolt retorquing, transmission oil changes, clutch system fluid check/correction.
Troubleshooting And Repair:
Inspection of components, lines, hoses, suspension, body structure, water leaks, corrosion. Diagnosis of common issues related to the diesel engine, fuel system, cooling, and other covered systems. Repair procedures for various components. Wheel bolt tightening, brake adjustment, parking brake adjustment.
Depth:
Comprehensive factory-level service and repair information, suitable for dealership technicians and experienced DIY mechanics. Covers routine maintenance to in-depth repairs.
Engine Type:
Inline 5-Cylinder Diesel with Turbocharger
Engine Displacement:
3.0 Liters (2998 cc)
Bore X Stroke:
87.0 mm x 84.0 mm
Compression Ratio:
21.0:1
Horsepower At Rpm:
Approximately 115 hp @ 4350 rpm (may vary slightly by specific model year/market)
Torque At Rpm:
Approximately 177 lb-ft (240 Nm) @ 2400 rpm (may vary slightly by specific model year/market)
Injection System:
Bosch Inline Injection Pump (VE type) with Mechanical Governor
Valve Adjustment:
Periodic adjustment required, typically via shim adjustment
Timing Belt Chain:
Timing Chain (no replacement interval, but requires inspection)
Injection Timing:
Critical for performance and emissions, requires precise adjustment with dial indicator or specialized tools.
Engine Oil And Filter:
Typically every 5,000-7,500 miles (8,000-12,000 km) or annually, depending on driving conditions. Refer to the manual for precise intervals.
Transmission Fluid And Filter:
Automatic transmission fluid and filter change recommended every 30,000-50,000 miles (48,000-80,000 km). Manual transmission fluid change typically every 50,000-60,000 miles (80,000-100,000 km).
Coolant Replacement:
Every 2-3 years or 30,000-45,000 miles (48,000-72,000 km).
Fuel Filter Replacement:
Annually or every 15,000-20,000 miles (24,000-32,000 km).
Engine Oil:
API CD or CE classification diesel engine oil, viscosity grade typically 15W-40 or 10W-40 depending on climate. Refer to manual for exact specification.
Coolant:
Ethylene glycol-based antifreeze mixed with distilled water, typically a 50/50 ratio. Check manual for specific Mercedes-Benz approved coolant.
Common Wear Items:
Glow plugs, vacuum lines (especially for central locking and climate control), fuel injection pump seals, suspension bushings, exhaust components, and potential rust in common areas like wheel arches and rocker panels.
Diesel Specific Issues:
Injection timing drift, injector wear, potential injector pump issues if fuel quality is poor or maintenance is neglected.
Manufacturer Legacy:
Mercedes-Benz has a long-standing reputation for building durable, reliable, and safe luxury vehicles, particularly known for its diesel engines.
W123 Development:
The W123 series was a significant success for Mercedes-Benz, continuing the company's tradition of engineering excellence and durability. The introduction of the turbocharged diesel variant (300 D Turbo) significantly enhanced performance over earlier naturally aspirated models.
Production Years Specific Model:
1982-1985
Manufacturing Locations:
Primarily Germany (Sindelfingen and Bremen plants), with some assembly in other international locations.
