Market Segment:
Luxury Mid-Size Diesel Sedan/Coupe
Key Competitors:
BMW 5 Series Diesel, Audi 5000 Diesel (though less prevalent in North America), Volvo Diesel variants.
Brand Perception:
Reputation for build quality, durability, and sophisticated engineering.
Powertrain Emphasis:
Renowned for its robust and fuel-efficient OM617 turbocharged diesel engine.
Value To Owner:
Enables owners to perform dealer-level maintenance and repairs, saving costs and ensuring longevity.
Primary Coverage:
Service, Repair, Maintenance
Secondary Coverage:
Diagnostics, Troubleshooting, Adjustments, Inspections
Estimated Page Count:
Varies by exact manual, but factory manuals are typically extensive, often exceeding 1000 pages for a full set.
Type:
Factory Service Manual / Workshop Manual
Format:
Digital Download (PDF)
Engine:
OM617 Diesel Engine (including fuel injection, cooling, lubrication, exhaust)
Transmission:
Manual and Automatic Transmissions (fluid changes, level checks, adjustments)
Suspension:
Front and Rear Axles, Suspension Components, Level Control (ADS), Self-Leveling Suspension
Brakes:
Hydraulic Brake System (fluid, lines, pads, discs, parking brake), ABS (if equipped)
Steering:
Power Steering System (fluid, play, adjustments)
Electrical:
Starting and Charging System, Lighting, Warning Lamps, Sensors, Fuses, Relays
Bodywork:
Body Structure Inspection, Water Leakage, Corrosion, Door Hinges, Hood, Sunroof, Soft Top, Wiper/Washer System, Doors, Locks, Windshield
HVAC:
Heating and Ventilation System, Coolant, AC Refrigerant Charge, Filters (Dust, Charcoal, Recirculating Air)
Maintenance:
Regular Scheduled Maintenance, Oil and Filter Changes, Fluid Replenishments, Belt Tensioning, Filter Replacements, Lubrication
Engine Repair:
Valve Clearance Adjustment, Injection Timing Adjustment, Fuel Filter Replacement, Spark Plug Replacement (if applicable to diesel variant), Manifold Seating Checks
Transmission Repair:
Fluid and Filter Changes, Oil Level Checks and Corrections for Manual and Automatic Transmissions, Clutch System Checks
Suspension Steering Repair:
Ball Joint Inspection, Axle Oil Level Checks, Steering Play Adjustment, Wheel Bolt Tightening, Drive Shaft Coupling Inspection
Brake Repair:
Brake Fluid Replacement, Parking Brake Adjustment, Brake Pad and Disc Inspection, Brake Line Inspection
Electrical Diagnostics:
Warning Lamp Checks, Battery Fluid Level Checks, Headlamp and Exterior Lamp Inspection
Body And Trim:
Lower Panel Removal/Installation, Lubrication of Hinges and Locks, Sunroof Rail Cleaning, Soft Top Inspection
Depth:
Comprehensive, covering all aspects from routine maintenance to component overhaul and diagnostic procedures.
Diagnostic Procedures:
Includes guidance for troubleshooting common issues and diagnostic checks for various systems.
Specifications:
Provides detailed technical specifications, tolerances, and torque values.
Engine Type:
Inline 5-cylinder Diesel
Displacement:
3.0 Liters (2999 cc)
Aspiration:
Naturally Aspirated (for the 300 CD designation, though a turbocharged version, OM617.95x, was common in the US market for similar models like the 300D and 300TD)
Horsepower:
Approximately 77-83 hp (for naturally aspirated variants, turbocharged versions produced more)
Torque:
Approximately 134-145 lb-ft (for naturally aspirated variants, turbocharged versions produced more)
Injection System:
Bosch Inline Fuel Injection Pump with Mechanical Governor
Coolant Type:
Ethylene Glycol based antifreeze/coolant (Mercedes-Benz recommends specific types, consult manual for part numbers like MB 325.0 or equivalent)
Oil Type:
API CD or CE rated diesel engine oil. Viscosity typically SAE 15W-40 or 10W-40 depending on climate. Consult manual for specific MB specifications.
Oil Capacity:
Approximately 7.5 liters (8 US quarts) with filter change.
Air Filter Type:
Paper element filter, potentially a metal-reinforced cleaning type.
Type:
4-Speed Manual Transmission (common)
Type:
4-Speed Automatic Transmission (common)
Manual Fluid Type:
Manual Transmission Fluid (MTF), typically GL-4 rated. Consult manual for specific MB specification (e.g., MB 235.0).
Automatic Fluid Type:
Dexron II or equivalent ATF. Consult manual for specific MB specification (e.g., MB 236.6).
Clutch Type:
Hydraulically actuated single dry plate clutch for manual transmission.
Crash Testing:
NHTSA ratings for this era are generally not comparable to modern standards. Emphasis was on structural integrity and passive safety features.
Brake Assist:
Not present in the modern sense; emphasis on robust hydraulic braking.
Airbags:
Not standard on this model year.
Seatbelts:
Standard front seatbelts, with options for rear seatbelts. Three-point inertial reel belts were becoming more common.
Structure:
Reinforced body structure, crumple zones designed for the era.
Oil Change Interval:
Typically every 10,000-15,000 km (6,000-9,000 miles) or annually, whichever comes first. Consult manual for precise recommendation.
Air Filter Replacement:
Every 20,000-40,000 km (12,000-25,000 miles), or as needed based on operating conditions.
Fuel Filter Replacement:
Every 20,000-40,000 km (12,000-25,000 miles).
Coolant Flush:
Every 2-3 years or as specified by coolant type.
Brake Fluid:
DOT 3 or DOT 4. Consult manual for specific Mercedes-Benz specification (e.g., MB 331.0).
Power Steering Fluid:
Hydraulic fluid, often MB specific. Consult manual for specification (e.g., MB 236.3).
Diesel Engine:
Glow plug issues, injector pump wear, vacuum leaks, potential for head gasket issues if overheated. OM617 is generally very robust.
Body:
Rust can be an issue, particularly in wheel arches, rocker panels, and around windows.
Suspension:
Wear in ball joints, bushings, and tie rod ends is common with age and mileage.
