🏷️ Basic Information

Make:

Mercedes-Benz

Model:

280 E

Year:

1981

Chassis Code:

W123

Engine Code Prefix:

M110

Generation Name:

W123 Sedan/Saloon

Generation Years:

1976-1985

👋 Introduction

Vehicle Segment:

Executive Mid-size Sedan. The W123 chassis was renowned for its build quality, durability, and engineering excellence, positioning it as a premium offering in its class.

Key Competitors:

BMW 5 Series (E28), Audi 100, Volvo 240, Jaguar XJ.

Vehicle Attributes:

Exceptional build quality, robust engineering, comfortable ride, durable powertrain, sophisticated styling, reputation for longevity and reliability.

Target Audience:

Owners seeking to maintain and repair their classic Mercedes-Benz, independent mechanics, restoration specialists.

📋 Manual Details

Primary Coverage:

Mechanical and electrical systems, maintenance, repair, troubleshooting, bodywork.

Specific Systems:

Engine, fuel system, ignition, cooling, exhaust, transmission (manual & automatic), driveline, suspension, steering, brakes, electrical system, body, climate control.

Estimated Pages:

High volume, detailed (typical for factory service manuals, often 1000+ pages when compiled).

Type:

Service and Repair Manual

Language:

English

File Format:

PDF / WINRAR

📖 Manual Coverage

Engine Mechanics:

Detailed inspection, disassembly, rebuilding, and assembly of engine components. Includes valve clearance adjustment, injection timing checks and adjustments, spark plug service, and engine mount retorquing.

Fuel System:

Inspection and replacement of fuel filters (primary and secondary), checking injection system condition.

Cooling System:

Checking coolant level and antifreeze protection, cooling and heating system checks, coolant replacement.

Ignition System:

Spark plug inspection and replacement.

Transmission Manual:

Manual transmission oil change, checking and correcting oil level, clutch disk wear inspection.

Transmission Automatic:

Automatic transmission fluid and filter change, checking and correcting fluid level.

Driveline:

Transfer case fluid change and level checks, front axle and rear axle oil changes and level checks, drive shaft flexible coupling inspection.

Suspension Steering:

Suspension and body structure inspection, inspecting self-leveling suspension, checking ball joints (with special tool), steering play checks, retightening steering bolts, level control system fluid level checks (ADS, ASD, 4MATIC).

Brakes:

Brake fluid level checks, brake line inspection, brake pad and disk thickness checks, brake disk cleaning, parking brake adjustment and testing, brake fluid replacement.

Electrical System:

Battery fluid level checks, warning and indicator lamp checks, headlamp and exterior lamp inspection.

Bodywork:

Water leakage and corrosion inspection, lubricating door hinges and locks, sunroof cleaning and lubrication, soft top checking, windshield wiper and washer inspection, cleaning water drains, removing/installing underbody panels, checking for paint damage.

Climate Control:

Checking and correcting AC refrigerant charge, replacing dust filters, replacing active charcoal filters, replacing recirculating air filters.

Routine Maintenance:

Oil and filter changes, air filter replacement, V-belt inspection and tensioning, spark plug replacement, fluid level checks and top-ups, lubrication points.

Troubleshooting:

Diagnosing vehicle problems, component condition inspection, line and hose inspection.

Component Rebuilding:

Disassembly, inspection, and reassembly of various vehicle components.

Adjustments:

Valve clearance, idle speed, injection timing, parking brake, engine stop.

Wheel Tire Service:

Wheel inspection and rotation, tire inspection and pressure correction, wheel bolt tightening.

Depth:

Comprehensive, covering detailed diagnostic procedures, component overhaul, and repair specifications. Suitable for professional mechanics and advanced DIY enthusiasts.

📊 Manual Specifications

Digital Formats:

PDF, WINRAR. Compatible with Windows (95 through 10), Linux, MAC OS, iOS, and Android devices.

Digital Quality:

High-resolution scans or digital creation, ensuring legibility of text and diagrams. Searchable text is a common feature of well-produced PDF manuals.

Digital Delivery:

Instant Download

Physical Format ABSence:

Not applicable as delivered digitally. Original manuals were typically printed on durable paper suitable for workshop environments.

⚙️ Engine Specifications

Engine Type:

Inline 6-Cylinder, SOHC (Single Overhead Camshaft)

Engine Code:

M110.984 (for 2.8L)

Displacement:

2746 cc (2.8 Liters)

Bore X Stroke:

86.0 mm x 78.0 mm

Compression Ratio:

8.2:1 or 9.0:1 (depending on market/spec)

Horsepower:

Approx. 138-145 hp (DIN) at 5000 rpm

Torque:

Approx. 225-230 Nm (166-170 lb-ft) at 3000 rpm

Fuel Delivery:

Bosch K-Jetronic (CIS - Continuous Injection System) Fuel Injection

Fuel Type:

Unleaded gasoline

Ignition Type:

Breakerless electronic ignition

Oil Capacity With Filter:

7.0 Liters (7.4 US Quarts)

Recommended Oil Viscosity:

SAE 20W-50 or SAE 15W-40 (depending on climate)

Oil Filter Part Number Example:

Mann-Filter W108/2, Mahle OC 103, Bosch 0451103032

🔧 Transmission

Transmission Type:

4-speed Manual Transmission

Transmission Type:

4-speed Automatic Transmission (optional)

Manual Fluid Type:

API GL-4 SAE 75W-90 or SAE 80W-90 gear oil

Automatic Fluid Type:

MB 236.3 (Dexron II compatible)

Manual Fluid Capacity:

Approx. 1.3 Liters

Automatic Fluid Capacity:

Approx. 7.5 Liters (total capacity, including torque converter)

📐 Dimensions

Length:

4725 mm (186.0 in)

Width:

1790 mm (70.5 in)

Height:

1440 mm (56.7 in)

Wheelbase:

2795 mm (110.0 in)

Curb Weight:

Approx. 1450-1550 kg (3197-3417 lbs)

Gross Vehicle Weight:

Approx. 1950 kg (4299 lbs)

🛡️ Safety Features

Crash Safety Era Design:

Designed to meet safety standards of the late 1970s and early 1980s. Features crumple zones, reinforced passenger cell, and safety glass.

Braking System:

Four-wheel disc brakes (front vented), dual-circuit hydraulic system.

Steering System:

Power-assisted recirculating ball steering.

Seatbelts:

Standard front seat belts, optional rear seat belts.

Headrests:

Integrated front headrests, rear headrests typically optional.

💡 Technology Features

Audio System:

Factory-installed Becker AM/FM radio with cassette player was common. Cassette deck tone head cleaning mentioned in manual.

Cruise Control:

Optional on some models.

Level Control:

Self-leveling rear suspension (often hydropneumatic) and optional ADS (Automatic Dampening System) and ASD (Automatic Slip Differential) on later W123 models, though ADS/ASD might be more prevalent on 4MATIC variants which began appearing towards the end of the W123's lifecycle and into the W124. The manual covers 'Level control, ADS, ASD, 4MATIC, fluid level'.

🔧 Maintenance

Oil Change Interval:

Typically every 10,000 - 15,000 km (6,000 - 9,000 miles) or 12 months, whichever comes first, depending on driving conditions. Consult the manual for precise intervals.

Air Filter Replacement:

Every 20,000 - 30,000 km (12,000 - 18,000 miles), or more frequently in dusty conditions.

Fuel Filter Replacement:

Every 20,000 - 30,000 km (12,000 - 18,000 miles).

Spark Plug Replacement:

Every 30,000 - 40,000 km (18,000 - 25,000 miles).

Valve Adjustment:

Recommended every 40,000 - 60,000 km (25,000 - 37,000 miles) or as indicated by engine performance issues.

Coolant Type:

Mercedes-Benz approved anti-freeze/anti-corrosion protection (typically phosphate-based for this era).

Brake Fluid Type:

DOT 3 or DOT 4 brake fluid

Power Steering Fluid Type:

MB 236.3 or Dexron II compatible automatic transmission fluid.

Common Problems:

Rust susceptibility (especially around wheel arches, door bottoms, and sunroof), aging rubber hoses and mounts, wear in the K-Jetronic fuel distributor (can cause rough idle or poor performance), vacuum leak issues, worn suspension bushings, occasional electrical contact issues.

📚 Vehicle History

Mercedes Benz Philosophy:

Known for engineering excellence, durability, safety, and a focus on building vehicles that last. The 'W123' generation exemplified these principles.

W123 Lineup:

Introduced in 1976, replacing the W114/W115. Offered in sedan, coupe, estate (S123), and long-wheelbase versions. The 280 E was a popular, well-equipped, and powerful variant of the W123.

Production Period:

W123 production: 1976-1985. The 280 E variant was produced throughout this period.

🏆 Awards & Recognition

Industry Acclaim:

The W123 chassis, as a whole, received numerous accolades during its production run for its durability and build quality, often cited in automotive publications as a benchmark for its era.