Market Segment:
Luxury Executive Sedan
Target Audience:
Luxury car buyers seeking comfort, safety, and performance, with a focus on engineering excellence.
Key Competitors:
BMW 7 Series, Audi V8, Jaguar XJ, Lexus LS (later in production).
Brand Heritage:
Mercedes-Benz is renowned for its pioneering safety features, robust engineering, and luxurious comfort, establishing itself as a benchmark in the automotive industry.
Model Philosophy:
The W126 S-Class represented the pinnacle of automotive engineering and luxury for its era, emphasizing driver and passenger safety, comfort, and sophisticated performance.
Value For Owner:
Provides dealership-level repair information, empowering owners for DIY maintenance and repairs, saving significant costs and ensuring correct servicing.
Engine:
Detailed diagnostics, repair procedures, specifications, torque values, timing, fuel injection (KE-Jetronic), ignition, lubrication, cooling system.
Transmission:
Automatic transmission (e.g., 722.4), diagnosis, adjustment, overhaul, fluid specifications, and torque converter.
Brakes:
Hydraulic system, ABS (Anti-lock Braking System), disc brakes (front and rear), parking brake, brake fluid specifications, bleeding procedures, component replacement.
Suspension:
Front suspension (independent), rear suspension (multi-link independent), steering system, shock absorbers, springs, bushings, alignment specifications.
Electrical System:
Complete wiring diagrams, fuse box layouts, component testing, diagnostic procedures for ignition, lighting, starter, alternator, battery, power windows, central locking, climate control.
Bodywork And Trim:
Exterior trim, interior trim, seats (adjustment, repair), doors, windows, sunroof, body panel removal and installation, sound deadening.
Climate Control:
HVAC system diagnosis, refrigerant, compressor, fan, heater core, climate control unit operation and repair.
Fuel System:
Fuel tank, fuel pump, fuel lines, fuel filter, fuel injection system (KE-Jetronic) components, pressure testing.
Maintenance:
Routine service, oil changes, filter replacements, fluid checks and changes, spark plug replacement, belt inspection and replacement.
Troubleshooting:
Diagnostic flowcharts, symptom-based troubleshooting guides, common fault identification.
Repair And Overhaul:
Engine component rebuilds, transmission overhauls, brake caliper replacement, suspension component replacement, electrical component repair.
Diagnosis:
System-specific diagnostic procedures, electrical testing, mechanical system checks.
Depth Of Information:
Comprehensive; covers everything from basic fluid changes to complete engine and transmission rebuilds. Includes detailed technical specifications and diagnostic procedures used by dealership technicians.
Engine Type:
Inline 6-cylinder, SOHC (Single Overhead Camshaft)
Displacement:
2.960 cc (3.0 Liters)
Horsepower:
Approx. 188 hp @ 5,700 rpm (DIN)
Torque:
Approx. 207 lb-ft (280 Nm) @ 4,400 rpm (DIN)
Fuel Injection System:
Bosch KE-Jetronic (Electronic Fuel Injection with Air Flow Sensor)
Fuel Type:
Unleaded gasoline (Premium Octane recommended)
Coolant Type:
Mercedes-Benz approved coolant (e.g., G48) mixed with distilled water (50/50 ratio).
Crash Test Reputation:
The W126 platform was a leader in safety for its time, with a robust body structure and pioneering safety features.
ABS:
Standard Anti-lock Braking System (ABS).
Traction Control:
Optional (ASR - Acceleration Slip Regulation) on some later models, though not standard on all 300SE variants.
Airbags:
Driver's airbag standard from approximately 1987 onwards; passenger airbag optional.
Seatbelts:
Pretensioners for front seatbelts.
Audio System:
Typically featured premium Becker or Blaupunkt audio systems, often with cassette player and optional CD changer.
Display Technology:
Analog gauges, climate control displays, and basic information displays.
Cruise Control:
Standard cruise control system.
Power Features:
Power windows, power locks, power seats (often with memory function), power steering, power antenna.
Early Connectivity:
While limited by modern standards, features like central locking and power windows provided early forms of vehicle integration. Later models might have offered antenna-based phone integration.
Oil Change Interval:
Typically every 5,000-7,500 miles (8,000-12,000 km) or annually, depending on driving conditions and oil used (consult manual for exact specs).
Transmission Fluid Change Interval:
Recommended every 30,000-50,000 miles (48,000-80,000 km).
Engine Oil Specification:
API SG or higher, SAE 10W-40 or 15W-40 (consult manual for precise viscosity and MB approval specification).
Engine Oil Capacity:
Approx. 7.5 liters (with filter change).
Coolant Capacity:
Approx. 9.5 liters.
Common Issues List:
Wiring harness degradation (especially around engine bay), fuel distributor leaks, vacuum hose deterioration, blower motor resistor failure, sunroof drain blockage, OVP relay failure, valve stem seal wear, rear axle mount cracking.
Key Preventative Tasks:
Regularly inspect and replace deteriorating vacuum lines and wiring harness insulation. Clean sunroof drains. Check OVP relay for proper function. Monitor fuel pressure and listen for leaks.
Manufacturer History:
Founded in 1926, Mercedes-Benz has a long-standing reputation for luxury vehicles, engineering innovation, and motorsport success.
W126 Introduction:
The W126 S-Class was introduced in 1979 as the successor to the W116 S-Class, representing a significant evolution in design, aerodynamics, and safety.
W126 Facelift:
The W126 received a significant facelift in 1985, introducing new engines (like the M103), improved aerodynamics, updated interior, and standard driver's airbag. The 300SE model was introduced with this facelift.
Production Period:
The W126 chassis was produced from 1979 to 1991. The 300SE specifically was part of the post-facelift era (1985-1991).
Manufacturing Locations:
Primary production in Sindelfingen, Germany.
