Segment:
Executive Sedan / Mid-size Luxury Sedan
Reputation:
Renowned for build quality, durability, engineering excellence, and comfort.
Competitors Era:
BMW 5 Series (E28/E34), Audi 100/200, Volvo 740/760, Lexus LS 400 (later models).
Body Styles:
Sedan (W124.030), Coupe (C124), Convertible (A124), Wagon (S124), Limousine (V124).
Engineering Focus:
Over-engineered, robust construction, sophisticated independent suspension, advanced safety features for its time.
Engine Mechanical:
Full rebuild procedures, component testing, timing, lubrication system, cooling system, exhaust system.
Engine Management:
Fuel injection (KE-Jetronic), ignition system, sensor diagnostics, ECU troubleshooting.
Transmission:
4-speed automatic (722.3/722.4) and manual transmission (G5/G7) overhaul, diagnostics, fluid service.
Drivetrain:
Driveshafts, differential, axle components, universal joints.
Suspension Steering:
Front and rear suspension components, alignment specifications, power steering system, steering gear.
Brakes:
Hydraulic system, ABS (Anti-lock Braking System) diagnosis, caliper and rotor replacement, parking brake.
Electrical System:
Wiring diagrams, component testing, starter, alternator, battery, lighting, fuses, relays.
Climate Control:
HVAC system, AC compressor, refrigerant, heater core, climate control unit troubleshooting.
Body Chassis:
Body panel removal/installation, door mechanisms, glass, seals, structural components.
Interior:
Seating, trim panels, dashboard removal, instrument cluster, seat belts.
Routine Maintenance:
Oil change, filter replacement, spark plug service, air filter replacement, coolant flush.
Troubleshooting Guides:
Systematic diagnostic procedures for common and uncommon faults.
Component Replacement:
Detailed step-by-step instructions for replacing major and minor components.
Overhaul Rebuild:
Complete instructions for engine, transmission, and differential rebuilds.
Electrical Diagnosis:
Using multimeters, oscilloscopes, and logic probes for fault finding.
Specifications Data:
Torque values, clearances, fluid types and capacities, electrical resistance values.
Depth:
Comprehensive: Covers everything from basic preventative maintenance to complete engine and transmission overhauls and advanced electrical diagnostics.
Diagnostic Tools:
References for specialized tools and diagnostic equipment where applicable.
Engine Type:
Inline-6 Cylinder, Naturally Aspirated
Displacement:
2962 cc (3.0 Liters)
Bore X Stroke:
88.5 mm x 80.25 mm
Horsepower:
188 hp @ 5700 rpm (approx.)
Torque:
207 lb-ft @ 4400 rpm (approx.)
Fuel Delivery:
Bosch KE-Jetronic Electronic Fuel Injection with Lambda Control
Fuel Type:
Unleaded Premium Gasoline (91+ Octane Recommended)
Ignition System:
Electronic Ignition with Knock Sensor
Transmission Type:
4-Speed Automatic (722.3 Series)
Transmission Type:
5-Speed Manual (G5/G7 Series)
Automatic Features:
Hydraulic control, lock-up torque converter.
Automatic Transmission Fluid:
MB 236.7, MB 236.8 (Dexron II/III equivalent)
Automatic Transmission Capacity:
Approx. 7.5 - 8.5 Liters (including torque converter)
Crash Test Data:
While formal crash test ratings from NHTSA/IIHS were less standardized in this era, the W124 was engineered with a very strong chassis and safety cage, considered among the safest cars of its time.
ABS:
Standard on 300E models from later years within this range, optional on earlier.
Traction Control:
Optional on some later models, often referred to as ASR (Anti-Slip Regulation).
Airbags:
Driver airbag became standard during this generation's run.
Seat Belts:
Pre-tensioning front seat belts.
Body Construction:
Reinforced passenger cell, crumple zones, side-impact protection.
Oil Change Interval:
Every 15,000 km (9,000 miles) or annually, whichever comes first (check owner's manual for specific interval based on driving conditions).
Major Service Intervals:
Refer to manual for specific mileage-based major services (e.g., spark plugs, fuel filter, transmission service).
Engine Oil:
API SG or higher, SAE 15W-40 or 10W-40 (refer to manual for seasonal viscosity recommendations).
Coolant:
Mercedes-Benz approved coolant (e.g., G48 or equivalent) mixed 50/50 with distilled water.
Brake Fluid:
DOT 3 or DOT 4
Engine Oil Capacity:
Approx. 7.5 Liters (with filter)
Cooling System Capacity:
Approx. 9.5 Liters
Wiring Harness:
Biodegradable insulation on engine wiring harnesses can degrade over time, leading to electrical issues.
Cooling System:
Plastic coolant expansion tank can become brittle and crack; thermostat housing can leak.
Fuel System:
Fuel pressure regulator issues, distributor O-ring leaks (M103).
Suspension:
Front control arm bushings, ball joints, and rear subframe bushings can wear out.
Climate Control:
Blower motor resistor failures, vacuum leaks in the HVAC system.
Mercedes Benz Legacy:
Decades of engineering innovation, luxury, and durability.
W124 Introduction:
Introduced in 1984 (as 300TD/300D), gasoline models like the 300E followed in 1985. The W124 replaced the W123 and was known for its advanced engineering and aerodynamic design.
300E Positioning:
The 300E was a popular mid-range model, offering a balance of performance, efficiency, and luxury within the W124 lineup.
Production Years W124:
1984-1995 (sedan/coupe/wagon), 1991-1996 (convertible)
Manufacturing Location:
Germany
