Segment:
Luxury Personal Coupe
Era:
1980s flagship luxury
Competitors:
BMW 6 Series, Jaguar XJ-S, Rolls-Royce Corniche
Prestige:
Represents Mercedes-Benz's pinnacle of engineering and luxury for its time
Design:
Timeless coupe styling, aerodynamic efficiency
Engine:
Detailed overhaul, diagnostics, M117 V8 engine (5.0L)
Fuel System:
Bosch K-Jetronic fuel injection system diagnostics and repair
Ignition System:
Distributor ignition system, timing, troubleshooting
Transmission:
4-speed automatic transmission (4G-Tronic) service and repair
Drivetrain:
Rear-wheel drive, differential, driveshafts
Suspension:
Front and rear suspension components, adjustments, replacement
Steering:
Power steering system, steering gear, linkages
Brakes:
Hydraulic system, ABS (if equipped), caliper, rotor, pad service, bleeding
Electrical System:
12-volt system, battery, alternator, starter, lighting, fuses, relays
Climate Control:
Air conditioning system, heater core, blower motor, controls
Body And Chassis:
Body panel removal, interior trim, glass, seals
Diagnostics:
Troubleshooting charts, symptom-based diagnostics
Maintenance:
Scheduled maintenance, fluid changes, filter replacements
Repair:
Step-by-step repair instructions for all major components
Disassembly:
Detailed procedures for component removal and disassembly
Inspection:
Guidelines for inspecting wear, damage, and proper function
Reassembly:
Instructions for proper reassembly and adjustment
Specifications:
Torque values, clearances, measurements
Depth:
Comprehensive, from routine maintenance to major component overhaul
Diagnostics Level:
Advanced troubleshooting for mechanical and electrical systems
Displacement:
4973 cc (5.0 Liters)
Bore X Stroke:
96.0 mm x 85.0 mm
Compression Ratio:
8.3:1 or 8.8:1 (depending on market/variant)
Horsepower Gross:
230 hp @ 4750 rpm (Euro spec)
Torque Gross:
395 Nm (291 lb-ft) @ 3000 rpm (Euro spec)
Fuel Injection:
Bosch CIS-E (Continuous Injection System - Electronic)
Fuel Type:
Premium Unleaded Gasoline (91+ Octane)
Crash Testing Era:
Pre-modern safety standards; focus on passive safety
ABS:
Anti-lock Braking System (optional on some models/markets)
Seatbelts:
Three-point front seatbelts, rear seatbelts
Structure:
Reinforced passenger cell, crumple zones
Audio System:
Optional Becker premium audio systems, often with cassette player
Cruise Control:
Standard or optional electronic cruise control
Phone Integration:
None (era appropriate), but some may have had early car phone provisions
Climate Control:
Automatic climate control (optional/standard depending on trim)
Seats:
Power adjustable front seats with memory, heated seats (optional)
Oil Change Interval:
Typically every 10,000 km (6,000 miles) or 12 months
Major Service:
Refer to manual for specific mileage/time intervals for transmission fluid, coolant, etc.
Engine Oil Type:
API SF or SG, SAE 15W-40, 10W-40, or 5W-30 (depending on climate)
Engine Oil Capacity:
7.5 Liters (approx. 8 US quarts)
Transmission Fluid Type:
MB 236.3 (e.g., Dexron II)
Coolant Type:
Ethylene glycol-based coolant (e.g., MB 325.0 specification, typically 50/50 mix with distilled water)
Brake Fluid Type:
DOT 3 or DOT 4
Fuel System Aging:
Degradation of fuel lines, O-rings, and injector seals due to age and fuel composition
Electrical Component Failure:
Aging wiring harnesses, vacuum leaks affecting K-Jetronic, failing relays
Suspension Wear:
Worn control arm bushings, ball joints, and shock absorbers
Window Regulator Failure:
Common wear item on power window mechanisms
Headliner Sagging:
Fabric degradation over time
Brand Legacy:
Mercedes-Benz renowned for engineering, durability, and luxury since late 19th century
Predecessor:
W114/W115 Coupe, W123 Coupe
Successor:
C140 S-Class Coupe
Production Years C126:
1981-1991
Production Years Covered:
1984, 1985
Manufacturing Location:
Germany
