Positioning:
A premium executive sedan renowned for its build quality, comfort, and durability. The 280E was a significant model in Mercedes-Benz's lineup during the late 1970s and early 1980s.
Competitors:
BMW 5 Series (E12/E28), Audi 100/200, Volvo 240/700 Series, Cadillac Seville.
Distinguishing Features:
Robust engineering, plush interior, exceptional ride comfort, legendary reliability, sophisticated styling.
Years Covered:
1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985
Type:
Full Service & Repair Manual
Format:
Digital (PDF/eBook)
Mechanical:
Engine (M110), Fuel System (Bosch K-Jetronic), Ignition System, Cooling System, Exhaust System, Transmission (4-speed manual, 4-speed automatic), Clutch, Drivetrain, Suspension (front independent, rear independent), Steering System, Braking System (front discs, rear drums/discs), Chassis, Body Components
Electrical:
Wiring Diagrams, Lighting System, Starting System, Charging System, Instrumentation, Wiper System, Horn, Power Windows, Central Locking (if equipped), Radio (factory)
Maintenance:
Routine servicing (oil changes, filter replacements, spark plug changes, brake pad inspection), Fluid checks and top-offs, Belt adjustments, Lubrication points
Repair:
Engine overhaul, Cylinder head removal/installation, Fuel injection system diagnostics and repair, Ignition system troubleshooting, Transmission overhaul, Brake system repair, Suspension component replacement, Steering linkage repair, Cooling system leak repair, Electrical component testing and replacement
Diagnostics:
Troubleshooting charts for common problems, Component testing procedures, Diagnostic parameters for fuel injection and ignition systems
Depth:
Comprehensive, covering everything from basic tune-ups to major component overhauls and electrical system diagnostics.
Engine Type:
Inline-6, SOHC
Displacement:
2.8 Liters (2789 cc)
Bore X Stroke:
86.0 mm x 80.25 mm
Compression Ratio:
8.7:1 (typical)
Horsepower:
138-142 hp @ 5000-5500 rpm (depending on market and exact configuration)
Torque:
217-224 Nm (160-165 lb-ft) @ 3000-3500 rpm (depending on market and exact configuration)
Fuel Delivery:
Bosch K-Jetronic Mechanical Fuel Injection
Fuel Type:
Unleaded Gasoline (RON 91 or higher recommended)
Type:
Breakerless Electronic Ignition (CDI - Capacitive Discharge Ignition) for later models, or distributor-based for earlier ones.
Type:
Water-cooled, pressurized system
Coolant Type:
Ethylene Glycol based antifreeze (e.g., Mercedes-Benz Spec 325.0 or equivalent)
Type:
4-speed Manual Transmission
Type:
4-speed Automatic Transmission (Model 722.1 or 722.3)
Manual Gear Ratios:
Specific ratios vary, but generally feature a robust design for durability.
Automatic Features:
Lock-up torque converter for improved fuel efficiency at cruising speeds.
Automatic Fluid Type:
Dexron II or equivalent (refer to manual for exact spec)
Automatic Capacity:
Approximately 7.5-8.5 liters (with torque converter)
Length:
Approx. 4725 mm (186.0 in)
Width:
Approx. 1790 mm (70.5 in)
Height:
Approx. 1420 mm (55.9 in)
Wheelbase:
Approx. 2795 mm (110.0 in)
Curb Weight:
Approx. 1450-1550 kg (3200-3400 lbs)
Gross Vehicle Weight:
Approx. 1950 kg (4300 lbs)
Trunk Volume:
Generous for its class, estimated around 520 liters (18.4 cu ft).
Crash Testing:
While formal NCAP ratings were not prevalent in this era, Mercedes-Benz vehicles of this vintage were built with robust safety structures and incorporated crumple zones. Independent tests of the era often highlighted superior crashworthiness compared to contemporaries.
Braking:
Four-wheel disc brakes (standard on some markets/later models, front discs standard, rear often drum but sometimes disc on higher specs) with power assist. Anti-lock Braking System (ABS) became available as an option on later W123 models, particularly towards the end of the production run.
Construction:
Reinforced passenger cell, crumple zones, safety glass all around.
Interior:
Safety-designed dashboard, collapsible steering column, padded interior surfaces.
Audio System:
Factory fitted AM/FM radio with cassette player was common, often with optional upgraded speakers. Many owners upgraded these over time.
ABS:
Optional on later models, a significant safety advancement for its era.
System Type:
Manual ventilation and heating, with optional (and highly regarded) fully automatic climate control (Thermatic) becoming available on higher trims and later models.
Features:
Power windows, power door locks, cruise control (optional), central locking (optional).
Oil Change:
Every 10,000 - 15,000 km (6,000 - 9,000 miles) or 12 months, whichever comes first (check manual for specific interval).
Air Filter:
Inspect every 10,000 km (6,000 miles), replace as needed or every 20,000-30,000 km (12,000-18,000 miles).
Spark Plugs:
Replace every 20,000 - 40,000 km (12,000 - 25,000 miles) depending on type and condition.
Fuel Filter:
Replace every 30,000 - 50,000 km (18,000 - 30,000 miles) due to K-Jetronic sensitivity.
Engine Oil:
API SG or SH rated, SAE 10W-40 or 15W-40 recommended for general use (check manual for specific viscosity based on climate).
Coolant:
50/50 mix of Mercedes-Benz approved coolant (e.g., ZEREX G-05, or equivalent meeting DIN 71700) and distilled water.
Engine Oil Capacity:
Approx. 6.5 - 7.0 Liters (with filter)
Cooling System Capacity:
Approx. 9.5 - 10.5 Liters
Engine:
Timing chain wear (rare but possible), valve stem seal degradation, oil leaks from various gasket points (e.g., oil pan, valve cover), fuel distributor issues (requiring specialized rebuild).
Electrical:
Degradation of wiring insulation (especially engine bay harness), failure of dashboard indicator lights, faulty vacuum lines affecting climate control.
Suspension Steering:
Wear in ball joints, tie rod ends, and control arm bushings; play in steering box; sagging front springs.
Body Chassis:
Rust proliferation, particularly around wheel arches, door bottoms, and jacking points; sagging headliner; worn door seals.
Fuel System:
Clogged fuel filter or strainer, vacuum leaks in the intake manifold or associated lines, faulty cold start injector or thermostat.
Heritage:
Mercedes-Benz has a long-standing reputation for engineering excellence, safety, and luxury that dates back to the invention of the automobile.
W123 Lineage:
The W123 chassis was introduced in 1975 and succeeded the W114/W115 range. It was a significant evolution in design, engineering, and safety. The 280E represented the higher-end gasoline engine option in the sedan lineup, positioned below the larger S-Class.
Production Years Global:
1975-1985 (sedans and estates), 1977-1985 (coupes), 1978-1985 (long-wheelbase sedans).
Assembly Locations:
Various Mercedes-Benz plants, including Sindelfingen, Germany.
Historical Recognition:
Consistently lauded in contemporary automotive reviews for its build quality, comfort, and durability, often cited as a benchmark for luxury sedans.
Reliability Perception:
High, with a reputation for lasting hundreds of thousands of miles when properly maintained. Often referred to as 'over-engineered'.
Compliance:
Met or exceeded all applicable safety and emissions standards for its production years in major global markets.
