Target Audience:
Owners of Mercedes-Benz 300 SE models from 1988-1993, DIY mechanics, professional automotive technicians, and classic car enthusiasts looking for in-depth repair and maintenance information.
Value Proposition:
Provides a consolidated and comprehensive resource for multiple model years of the W126 300 SE, offering detailed repair and diagnostic procedures that are essential for maintaining these luxury vehicles. Its digital format ensures immediate accessibility.
Manual Benefits:
Covers a wide range of repair and maintenance tasks across multiple model years, enabling owners to perform both routine service and complex repairs. Focuses on problem diagnosis and repair procedures, enhancing practical application.
Engine:
Engine oil and filter change, valve clearance adjustment and checking, idle speed checking and adjustment, injection timing checking and adjustment, fuel filter replacement, air filter replacement, V-belt inspection, intake/exhaust manifold seating, oxygen sensor replacement, spark plug inspection and replacement, coolant level and antifreeze protection checking, cooling system inspection, coolant replacement, engine mounts, throttle linkage.
Transmission:
Manual transmission oil change, fluid level checking and correction. Automatic transmission fluid and filter change, fluid level checking and correction. Transfer case fluid change and fluid level checking and correction.
Suspension And Steering:
Suspension and body structure inspection, level control (ADS, ASD, 4MATIC) fluid level, self-leveling suspension inspection, front axle oil level checking, front axle ball joint checking, rear axle oil change, rear axle oil level checking, rear axle mount adjustment, steering play checking, steering bolt retightening.
Brakes:
Brake fluid level checking, brake line inspection, brake pad and disk thickness inspection, brake disk inspection and cleaning, parking brake cable inspection and adjustment, brake fluid replacement, brake test and parking brake check.
Electrical And Lighting:
Warning and indicator lamp checking, headlamp and exterior lamp inspection, windshield wiper and washer inspection.
Body And Chassis:
Water leakage and corrosion inspection, wheel inspection and rotation, tire inspection and pressure correction, wheel bolt tightening, drive shaft flexible coupling inspection, engine compartment lower panel removal/installation, door hinge lubrication, door lock lubrication, sunroof rail cleaning and greasing, soft top locking tab checking, windshield wiper blade replacement, hood lubrication, safety belt inspection, backrest lock operation check, lower noise encapsulation panel removal/installation, body paint damage inspection.
Climate Control:
AC refrigerant charge checking and correction, dust filter replacement, active charcoal filter replacement, recirculating air filter replacement.
Maintenance:
Regularly scheduled maintenance tasks such as fluid changes (engine oil, transmission fluid, rear axle oil, transfer case oil, brake fluid, power steering fluid, windshield washer fluid, coolant), filter replacements (oil, fuel, air, dust, charcoal, recirculating air), belt inspection and replacement, spark plug replacement, and lubrication of various components.
Troubleshooting And Diagnostics:
Aids in determining the cause of vehicle-related problems. Specific diagnostics mentioned include injection timing, idle speed, and various system checks.
Repair And Rebuilding:
Procedures for disassembly, inspection of parts for reuse, rebuilding, and assembly of components are explicitly stated as a primary purpose of the manual.
Depth Of Coverage:
Comprehensive, covering everything from basic fluid checks and filter changes to component disassembly, inspection, rebuilding, and reassembly. It caters to both DIY enthusiasts and professional mechanics for in-depth repair and diagnostics.
Engine Type:
Inline 6-Cylinder (M103)
Engine Displacement:
2.960 cc (3.0 Liters)
Engine Designation:
M103.984
Horsepower Approximate:
189 hp (141 kW) @ 5,700 rpm (varies slightly by year and market)
Torque Approximate:
238 lb-ft (322 Nm) @ 4,400 rpm (varies slightly by year and market)
Fuel Delivery System:
Bosch KE-Jetronic (K-Jetronic with Lambda control)
Fuel Type:
Unleaded Premium Gasoline
Coolant Type Specification:
MB specification 325.0 (Antifreeze/Coolant Concentrate, typically silicate-free blue/green ethylene glycol based)
Engine Oil Viscosity:
SAE 15W-40 or 5W-40 recommended, depending on climate. Consult manual for exact MB-Approval specifications (e.g., MB 229.1).
Engine Oil Capacity:
Approximately 6.0 - 6.5 liters (6.3 - 6.9 US quarts) with filter change.
Standard Transmission Type:
4-Speed Automatic Transmission (722.3 series)
Optional Transmission Type:
5-Speed Manual Transmission (historically rare for 300 SE in many markets, but may be covered)
Automatic Transmission Fluid Type:
MB specification 236.1 (Dexron II or equivalent)
Automatic Transmission Fluid Capacity:
Approximately 2.5 - 3.0 liters (2.6 - 3.2 US quarts) for fluid and filter change.
Manual Transmission Fluid Type:
MB specification 235.0 or 235.1 (API GL-4 gear oil)
Transfer Case Fluid Type:
N/A for standard RWD 300 SE models. If 4MATIC variant is covered, specific MB specification for transfer case fluid would apply (e.g., MB 235.6).
Infotainment Features:
Basic for its era: AM/FM radio with cassette deck, power antenna. Cassette deck tone head cleaning is mentioned, indicating routine maintenance for audio components.
Driver Assistance Systems:
Optional: Anti-lock Braking System (ABS), Acceleration Skid Control (ASR - later models), Automatic Locking Differential (ASD), Level Control (Hydropneumatic suspension/ADS). These complex systems are detailed in the manual.
Connectivity Features:
Minimal by modern standards. Primarily focused on internal vehicle systems. Antenna mast cleaning is mentioned.
Engine Oil Change Interval:
Typically 10,000-15,000 km (6,000-9,000 miles) or annually, depending on driving conditions. Consult manual for exact intervals and Mercedes-Benz service bulletins.
Transmission Fluid Change Interval:
Automatic transmission fluid and filter change: Typically every 50,000-80,000 km (30,000-50,000 miles). Manual transmission fluid: Less frequent, often every 80,000-100,000 km (50,000-60,000 miles).
Brake Fluid Specification:
DOT 4 (refer to manual for specific MB approval, e.g., MB 331.0)
Power Steering Fluid Type:
MB specification 236.3 (ATF Dexron II or equivalent)
Common W126 300Se Issues:
Potential issues include: fuel distributor problems, vacuum hose leaks, ABS sensor failures (for models with ABS), blower motor resistor failure, sagging headliner, SRS system faults, window regulator issues, and water pump leaks. The manual's diagnostic sections are crucial for addressing these.
Mercedes Benz Legacy:
Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, safety, and durability, with the S-Class (W126) being a flagship model representing these values.
W126 Second Generation:
The W126 chassis, produced from 1979 to 1991, underwent a significant facelift in 1985. The 300 SE was introduced in 1985/1986, featuring the new M103 inline-six engine, replacing earlier 2.8L and 3.0L variants. The 1988-1993 range represents the updated post-facelift models.
Production Period:
W126 production: 1979-1991. The 300 SE was part of the later production years. The manual covers a period extending slightly beyond the typical end of W126 production, possibly including some very early W140 transition models or specific market variations.
