Positioning:
Luxury Grand Tourer Coupe, representing Mercedes-Benz's pinnacle of engineering and design for the era.
Competitors:
BMW 6 Series (E24), Jaguar XJ-S, Maserati Quattroporte (though different body style).
Design:
Elegant pillarless coupe design, aerodynamic profile, high-quality interior materials.
Powertrain:
Smooth and powerful M116 3.8L V8 engine, refined automatic transmission.
Comfort And Luxury:
Luxurious appointments, advanced climate control for its time, exceptional ride comfort.
Powertrain:
Engine (M116), Fuel System, Ignition System, Cooling System, Exhaust System, Transmission (722.3 Automatic)
Chassis:
Suspension (Front & Rear), Steering System, Braking System (ABS optional), Drivetrain (Driveshafts, Differential)
Electrical:
Wiring Diagrams, Lighting System, Instrumentation, Power Accessories, Climate Control Electronics, Engine Control Unit (ECU) Diagnostics
Body And Interior:
Body Panels, Doors, Windows, Convertible Top Mechanism (if applicable to sub-models, though SEC is Coupe), Interior Trim, Seats, Climate Control (HVAC)
Maintenance:
Routine Servicing, Oil Changes, Filter Replacements, Spark Plug Replacement, Belt Inspection and Replacement, Fluid Checks and Top-offs
Repair:
Engine Overhaul, Transmission Rebuild, Brake Component Replacement, Suspension Component Replacement, Electrical Component Repair, Fuel System Component Repair
Troubleshooting:
Diagnostic Flowcharts, Common Faults and Solutions, Electrical System Troubleshooting, Engine Performance Issues, Transmission Shifting Problems
Diagnostics:
OBD-I (On-Board Diagnostics) procedures, Fault Code Interpretation (where applicable), Sensor Testing, Actuator Testing
Depth:
Comprehensive from basic maintenance to complete engine and transmission overhauls. Includes detailed diagnostic procedures and component-level repair instructions.
Displacement:
3839 cc (3.8 Liters)
Bore X Stroke:
92.0 mm x 71.5 mm
Compression Ratio:
8.3:1 (approx.)
Horsepower:
155-160 hp @ 4750-5000 rpm (SAE net)
Torque:
220-225 lb-ft @ 2500-3000 rpm (SAE net)
Fuel Delivery:
Bosch K-Jetronic Fuel Injection (CIS - Continuous Injection System)
Fuel Type:
Unleaded Gasoline (Premium)
Ignition System:
Electronic Ignition with breakerless distributor
Crash Test Era:
Pre-modern crash testing standards, emphasis on passive safety features of the era.
ABS:
Optional Anti-lock Braking System (ABS) available on some models.
Suspension Stability:
Independent suspension contributing to stable handling.
Airbag:
No driver or passenger airbags standard in this period; steering wheel airbag not common yet.
Seatbelts:
3-point inertia-reel seat belts (front), lap belts (rear).
Body Structure:
Reinforced passenger compartment, crumple zones.
Radio:
Period-appropriate Becker or Blaupunkt AM/FM/Cassette stereo systems, often with power antenna.
Climate Control:
Automatic Climate Control (ACC) with manual override, using vacuum-actuated flaps and electronic sensors for temperature regulation.
Cruise Control:
Standard cruise control system.
Telematics:
No integrated telematics or smartphone connectivity. Communication systems are limited to the period's radio and telephone options.
Oil Change:
Every 5,000 - 7,500 miles or 6-12 months (whichever comes first), consult manual for specific interval.
Air Filter:
Inspect every 15,000 miles, replace as needed or every 30,000 miles.
Spark Plugs:
Replace every 30,000 - 40,000 miles (refer to manual for specific type and gap).
Transmission Service:
Drain and fill every 30,000 - 50,000 miles (refer to manual for specific fluid and procedure).
Engine Oil:
API SG/SH or higher, SAE 10W-40 or 15W-40 (check manual for ambient temperature recommendations and specific MB approval).
Engine Oil Capacity:
7.5 Liters (7.9 US Quarts) with filter change.
Coolant:
50/50 mixture of Mercedes-Benz approved coolant (e.g., G48) and distilled water.
Brake Fluid:
DOT 4 Synthetic Brake Fluid.
Fuel System:
K-Jetronic fuel distributors can become clogged; periodic cleaning or rebuilding may be necessary. Fuel pump strainers can clog. Leaky fuel injectors.
Electrical:
Wire loom degradation (especially around engine bay), faulty climate control modules, aging vacuum lines for central locking and HVAC.
Suspension And Steering:
Wear in ball joints, tie rod ends, and bushings can lead to steering looseness and uneven tire wear. Hydraulic self-leveling rear suspension (if equipped) can develop leaks.
Rust:
Common areas include wheel arches, rocker panels, door bottoms, and around the windshield seal.
Transmission:
Solenoid issues, torque converter problems, and worn clutch packs can occur with high mileage.
Heritage:
Mercedes-Benz has a long-standing reputation for building durable, luxurious, and technologically advanced vehicles since its inception.
Predecessor:
350SLC (R107 coupe version), 450SLC (R107 coupe version).
Successor:
560SEC (W126 SEC Coupe, which superseded the C107 SEC line).
Production Years:
1980-1981 (380SLC/SEC), 1982-1985 (380SEC). This manual covers the specific 1982-1983 model years of the C107 chassis SEC coupe.
Manufacturing Location:
Germany
