Market Position:
The Mercedes-Benz 380 SEC (C126) represented the pinnacle of luxury personal coupes in its era, targeting affluent buyers who valued performance, comfort, and cutting-edge engineering. It competed with other high-end European coupes.
Competitive Analysis:
Competed primarily with models like the BMW 6 Series (E24), Porsche 928, and Jaguar XJ-S, offering a blend of sophisticated technology, luxurious appointments, and powerful V8 performance distinct from its rivals.
Key Features Of Vehicle:
Elegant pillarless coupe design, potent V8 engine, advanced (for its time) suspension and braking systems, luxurious interior appointments, sophisticated styling, and the renowned Mercedes-Benz build quality.
Coverage Areas:
Engine, Brakes, Suspension, Steering, Fuel System, Ignition System, Electrical System, HVAC, Bodywork, Exterior Trim, Interior Trim, Seats, Transmission, Drivetrain, Wheels, Tires, Diagnostic Procedures, Troubleshooting
Estimated Page Count:
Extensive (factory manuals are typically hundreds of pages, often presented in multiple volumes or sections)
Manual Type:
Factory Workshop Service Repair Manual
Language:
English (assumed for typical North American market distribution, though factory manuals can be multilingual)
Digital Format:
HTML/Flash menu with PDF content
Systems Covered:
Engine Mechanical, Engine Control Unit (ECU), Fuel Injection (K-Jetronic), Ignition, Cooling System, Lubrication System, Exhaust System, Transmission (Automatic), Differential, Drive Axles, Suspension (Front & Rear), Steering System, Braking System (ABS potentially), Climate Control (HVAC), Electrical Systems (lighting, instruments, power accessories), Body & Chassis, Interior Components (seats, trim), Exterior Trim & Bumpers, Diagnostic Trouble Codes (DTCs) interpretation
Procedures Included:
Routine Maintenance, Scheduled Service, Component Removal & Installation, Reassembly, Adjustments, Diagnostics, Troubleshooting, Component Testing, Wiring Diagrams, Technical Specifications, Torque Values, Fluid Capacities, Special Tool Requirements, Overhaul Procedures (e.g., transmission, engine components)
Technical Depth:
Comprehensive: Covers everything from basic fluid changes and filter replacements to complete engine and transmission rebuilds, complex electrical diagnostics, and bodywork repairs. Designed for professional technicians but accessible to experienced DIYers.
File Format Details:
Hybrid: HTML/Flash interface for navigation and menu-driven access, with core repair and diagnostic information presented in PDF documents for ease of printing and searching. Optimized for viewing on Windows and macOS operating systems.
Print Quality Output:
Printable PDF pages; high resolution suitable for detailed diagrams and illustrations. The original factory manual's print quality is maintained in the digital format.
Binding Type:
Digital/Electronic (no physical binding as it's a downloadable file)
Paper Type Equivalent:
Digital; equivalent to high-quality, durable paper stock used in professional service manuals.
Engine Code Displacement:
M116 3.8L (3818 cc) V8
Horsepower And Torque:
Approximately 155-160 horsepower and 197-200 lb-ft of torque (US market specifications may vary slightly). This was primarily focused on smooth power delivery and torque rather than outright sportiness.
Fuel System Type:
Bosch K-Jetronic CIS (Continuous Injection System) Fuel Injection
Engine Configuration:
SOHC V8
Cooling System Type:
Pressurized liquid cooling system with a fan clutch and coolant reservoir.
Ignition System Type:
Breakerless electronic ignition system with distributor.
Standard Transmission:
4-speed Automatic Transmission (722.3 series)
Optional Transmission:
Not typically offered in most markets; the automatic was standard for this luxury coupe.
Transmission Features:
Comfort-oriented shift points, torque converter lock-up for improved fuel efficiency at cruising speeds. Manual shifting modes (e.g., 'E' Economy and 'S' Standard) were common.
Wheelbase:
Approximately 115.9 inches (2945 mm)
Overall Length:
Approximately 195.9 inches (4975 mm)
Overall Width:
Approximately 70.5 inches (1790 mm)
Overall Height:
Approximately 55.4 inches (1408 mm)
Curb Weight:
Approximately 3,800 - 3,950 lbs (1725 - 1790 kg)
Gross Vehicle Weight Rating:
Typically around 4,800 - 5,000 lbs (2175 - 2270 kg)
Safety Ratings Era:
While specific crash test ratings from modern organizations like NHTSA or IIHS are not available for this era, Mercedes-Benz vehicles from this period were engineered to very high safety standards for their time, emphasizing occupant protection and structural integrity.
Active Safety Features:
Four-wheel disc brakes (potentially with ABS on later models or as an option), advanced suspension geometry for stability, power steering.
Passive Safety Features:
Reinforced body structure, energy-absorbing steering column, padded interior surfaces, height-adjustable seat belts, dual front airbags (standard from 1984 onwards, may have been optional or not present on early 1982/1983 models), automatic seat belt presenters.
Infotainment System:
Basic for its era: AM/FM radio with cassette player, often with a power antenna. Manual climate control with optional automatic climate control. Power windows, power locks, cruise control, and power adjustable seats were standard or common options.
Driver Assistance Features:
Limited by modern standards. Advanced Anti-lock Braking System (ABS) was available or standard depending on the specific model year and market. The car's primary assistance was its robust chassis and suspension design for stable handling.
Connectivity Features:
None by modern standards. Vehicles of this era were not equipped with Bluetooth, USB ports, or smartphone integration.
Typical Service Intervals:
Oil Changes: Every 3,000-5,000 miles (5,000-8,000 km) or 6-12 months. Major Services (filters, spark plugs, etc.): Typically at 15,000-30,000 mile intervals depending on the item. Refer to the specific manual for exact intervals and items.
Engine Oil Specification:
API SF or SG service classification. Viscosity: SAE 10W-40 or 15W-40 is common for this era, with 10W-30 acceptable in colder climates. Check specific manual for precise recommendations and MB approval numbers. Capacity: Approx. 8 quarts (7.5 liters) with filter.
Transmission Fluid Specification:
MB-Approval 236.3 Automatic Transmission Fluid (ATF). Example: Dexron III is often cited as a compatible replacement, but the factory MB fluid is preferred. Capacity: Approx. 2.5-3 quarts (2.4-2.8 liters) for a fluid change.
Coolant Specification:
Mercedes-Benz coolant/antifreeze, typically a 50/50 mix with distilled water. Color is usually blue or green. Capacity: Approx. 11 quarts (10.5 liters).
Brake Fluid Specification:
DOT 3 or DOT 4 brake fluid.
Common Issues And Maintenance Points:
K-Jetronic fuel system issues (clogged injectors, faulty fuel pressure regulator, air leaks), vacuum hose deterioration, climate control vacuum leaks causing control flap malfunctions, transmission valve body issues, rust (especially in wheel wells, rocker panels, and sunroof drains), aging electrical components (e.g., ABS controller, window regulators), suspension bushing wear, and potential head gasket leaks.
Brand Heritage:
Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, safety, and durability, dating back to the invention of the automobile. This heritage underpins the design and construction of models like the W126 SEC.
Model Evolution W126:
The W126 S-Class (sedan) debuted in 1979, and the C126 coupe variant, the SEC, followed in 1981. It replaced the C107 SLC and offered a more spacious, modern, and technologically advanced platform. The 380 SEC was the initial V8 offering, later replaced by the 420 SEC and 560 SEC.
Production Years For 380 Sec W126:
1981-1985 (with 1982-1983 being the specific focus of this manual).
