Vehicle Segment:
Mid-size luxury sedan/coupe
Competitors 1985:
BMW 5 Series (E28), Audi 100, Volvo 700 Series, Cadillac Seville
Brand Reputation:
Renowned for build quality, durability, and engineering excellence
Engine Type:
Proven 3.0L inline-five cylinder turbocharged diesel engine
Transmission Type:
Robust 4-speed automatic transmission
Design Era:
Classic W123 chassis, known for solid construction and timeless styling
Manual Value Proposition:
Essential resource for maintaining the longevity and performance of a classic Mercedes-Benz
Engine:
Detailed diagnostics, overhaul, timing, fuel injection, cooling, lubrication, emissions control
Transmission:
Automatic transmission (4-speed 722.3) service, repair, and overhaul
Drivetrain:
Rear axle, driveshaft, CV joints, lubrication
Suspension:
Front and rear suspension systems, steering linkage, shock absorbers, springs
Brakes:
Front disc brakes, rear drum brakes, parking brake, hydraulic system, ABS (if equipped)
Electrical System:
Wiring diagrams, battery, alternator, starter, ignition system, lighting, instruments, power windows, central locking
Climate Control:
Heating and ventilation systems, A/C system (if equipped)
Body And Chassis:
Body panel removal and installation, doors, windows, interior trim, chassis components
Routine Maintenance:
Oil changes, filter replacements, fluid checks, belt adjustments
Troubleshooting:
Diagnostic charts, symptom-based problem solving
Repair Overhaul:
Step-by-step instructions for major component repairs and full rebuilds
Component Replacement:
Detailed guides for replacing common wear items and critical components
Torque Specifications:
Accurate torque values for all critical fasteners
Special Tools:
Identification and usage of specialized Mercedes-Benz tools
Depth:
Comprehensive, suitable for professional mechanics and experienced DIY enthusiasts
PDF Quality:
High-resolution, searchable text and clear diagrams
Diagrams:
Clear, detailed line drawings and schematics
Digital Format Suitability:
Printable pages for workshop use
Digital Version Benefit:
Instant access, easy searching, bookmarking capability
Engine Type:
Inline-5 Cylinder, Turbocharged Diesel
Displacement:
3.0 Liters (2998 cc)
Bore X Stroke:
87.0 mm x 92.4 mm
Compression Ratio:
21.0:1
Horsepower:
85 hp @ 4000 rpm (approx.)
Torque:
136 lb-ft @ 2400 rpm (approx.)
Injection System:
Bosch inline injection pump with pre-combustion chambers
Turbocharger:
Garrett AiResearch turbocharger
Crash Safety Philosophy:
Designed for superior passive safety with a robust safety cage and crumple zones
Brakes:
Power-assisted four-wheel disc brakes (front), rear drum brakes. Optional ABS available on later models.
Airbags:
Not standard, driver airbag optional on later W123 models.
Seatbelts:
Three-point inertia-reel seat belts front, two-point lap belts rear
Steering Column:
Collapsible steering column
Oil Change Diesel:
Every 5,000 - 7,500 miles or 6-12 months, depending on driving conditions
Fuel Filter Replacement:
Every 15,000 - 25,000 miles
Air Filter Replacement:
Every 15,000 - 25,000 miles
Transmission Service:
Every 30,000 - 50,000 miles for fluid and filter change
Engine Oil Diesel:
API CD or CE rated diesel engine oil, SAE 15W-40 (or 10W-40 in colder climates)
Engine Oil Capacity:
7.5 Liters (8.0 US quarts) with filter
Coolant:
50/50 mix of antifreeze and distilled water
Common Wear Items:
Glow plugs, vacuum lines, fuel injectors, suspension bushings, door seals
Diesel Specific Concerns:
Overheating due to clogged radiator or weak water pump, air in fuel system after filter change
Industry Acclaim:
W123 series widely praised for build quality, durability, and longevity. Often cited as one of Mercedes-Benz's finest models.
Consumer Reports Perception:
Generally rated highly for reliability and owner satisfaction, particularly diesel models.
