Segment:
Mid-size luxury sedan
Reputation:
Known for build quality, durability, and engineering excellence
Competitors:
BMW 5 Series, Audi 100/A6, Lexus LS, Cadillac DeVille
Design Philosophy:
Understated elegance, robust engineering, driver-focused ergonomics
Value Proposition:
Reliability, longevity, comfortable ride, sophisticated technology for its era
Engine:
Complete overhaul, fuel system, ignition system, cooling system, lubrication system, exhaust system
Transmission:
Automatic transmission (likely 722.4 or 722.5 variants), manual transmission (if applicable, though 300E typically automatic)
Drivetrain:
Rear-wheel drive, differential, driveshafts, axles
Suspension:
Front and rear suspension components, shock absorbers, springs, bushings
Brakes:
Hydraulic system, ABS (Antilock Braking System), brake pad/disc replacement, caliper service
Steering:
Power steering system, steering linkage, steering gear
Electrical:
Battery, charging system, starting system, lighting, instrumentation, body electrical, engine control unit (ECU)
HVAC:
Heating, ventilation, and air conditioning (HVAC) system, climate control
Bodywork:
Body panel repair, doors, windows, trim, bumpers
Interior:
Seats, dashboard, trim panels, safety restraints
Maintenance:
Oil changes, filter replacements (oil, air, fuel), spark plug replacement, coolant flush, brake fluid flush, transmission fluid change, differential fluid change
Repair:
Engine overhaul, head gasket replacement, timing belt replacement, transmission rebuild, brake caliper overhaul, suspension component replacement, electrical component repair, HVAC system repair
Troubleshooting:
Diagnostic procedures for engine performance issues, electrical faults, transmission problems, HVAC malfunctions
Diagnostics:
Detailed electrical diagrams, wiring schematics, diagnostic trouble codes (DTCs) for engine management systems
Depth:
Comprehensive, suitable for both DIY enthusiasts and professional mechanics
Engine Type:
Inline 6-cylinder, DOHC (Dual Overhead Camshaft)
Displacement:
2.8 Liters (2799 cc)
Bore X Stroke:
89.9 mm x 73.5 mm
Compression Ratio:
10.0:1 (typical for M104.942)
Horsepower:
197 hp @ 5,500 rpm (SAE net, typical)
Torque:
200 lb-ft @ 4,000 rpm (SAE net, typical)
Fuel Delivery:
Bosch KE-Jetronic (CIS-E/ECU controlled mechanical fuel injection)
Fuel Type:
Unleaded Premium Gasoline (91 Octane or higher recommended)
Coolant Type:
MB-Approved Antifreeze/Coolant (typically 50/50 mix of ethylene glycol and distilled water)
Oil Type Recommendation:
SAE 5W-40 or 0W-40 Synthetic (refer to manual for exact MB-Approval numbers like MB 229.1 or 229.3)
Oil Capacity:
Approximately 7.5 Liters (7.9 US Quarts) with filter change (verify in manual)
Spark Plugs:
NGK BKR6EK (or equivalent with correct heat range and gap, e.g., Bosch FGR6MQC or Champion RC9YC)
Type:
4-Speed Automatic (likely 722.4 or 722.5 variant)
Type:
5-Speed Manual (less common on 300E models)
Transmission Fluid Type:
MB-Approved ATF (e.g., MB 236.2, 236.3, or 236.6 – consult manual for specific requirement of the 722.4/722.5)
Transmission Fluid Capacity:
Approximately 7.0 Liters (7.4 US Quarts) for fill, higher for overhaul (verify in manual)
Audio System:
Factory-installed Becker radios were common, often with cassette tape players. Optional CD changers might be found.
Climate Control:
Optional automatic climate control (often referred to as 'Thermotronic') was available, offering more sophisticated temperature and air distribution management than manual systems.
Cruise Control:
Standard or optional feature for maintaining set speed.
Connectivity Era:
Limited by modern standards; no built-in Bluetooth or USB. Primarily analog systems.
Oil Change Interval:
Typically every 10,000-15,000 km (6,000-10,000 miles) or 12 months, whichever comes first, using synthetic oil.
Air Filter Replacement:
Every 30,000-50,000 km (20,000-30,000 miles) or as needed based on driving conditions.
Fuel Filter Replacement:
Every 40,000-60,000 km (25,000-40,000 miles).
Coolant Flush:
Every 2-3 years or 40,000-60,000 km (25,000-40,000 miles).
Transmission Fluid Change:
Every 60,000-100,000 km (40,000-60,000 miles) or 4-5 years for automatic transmissions.
Brake Fluid:
DOT 3 or DOT 4 (refer to manual for specific MB specification, e.g., MB 331.0)
Power Steering Fluid:
MB Power Steering Fluid (typically a Dexron-II equivalent or specific MB fluid, check manual)
Wiring Harness:
Can degrade over time, especially insulation, leading to electrical issues (e.g., fuel distributor harness).
Head Gasket:
While generally robust, can be susceptible to failure with age and maintenance neglect, particularly on M104 engines. Leakage at the front cover seal is also common.
Cooling System:
Plastic components like coolant expansion tanks and heater control valves can become brittle and crack.
ABS Module:
ABS control modules can fail with age.
Window Regulators:
Can wear out, causing windows to operate slowly or not at all.
Brand Focus:
Engineering excellence, luxury, durability, pioneering safety features
W124 Era:
Produced from 1984 to 1995/1997 (depending on market and body style), known as the 'Baby S-Class' for its build quality and design.
300E Positioning:
A strong performer in the W124 lineup, offering a balance of power and refinement with the inline-six engine.
Production Years W124:
1984-1997
Manufacturing Location:
Germany (Sindelfingen, Bremen), and other international assembly plants.
