Competitors 1990:
BMW 7 Series (E32), Lexus LS 400 (UCF10), Cadillac DeVille
Vehicle Attributes:
Exceptional build quality, refined ride, potent inline-six engine, advanced safety features for its era, spacious interior.
Manual Value Proposition:
Essential for DIY enthusiasts and professional mechanics to maintain and repair the sophisticated W126 chassis, providing detailed, factory-accurate information at a fraction of dealership costs.
Powertrain:
Engine, Fuel System, Cooling System, Exhaust System, Transmission (Automatic)
Chassis:
Suspension (Independent Front & Rear), Steering System, Brakes (ABS), Drivetrain (RWD)
Electrical:
Wiring Diagrams, Lighting, Ignition System, Battery, Charging System, Starter, ECUs, Sensors, Instruments
Body And Interior:
Body Panels, Doors, Windows, Seats, HVAC System, Climate Control, Sunroof, Interior Trim
Maintenance:
Routine Service, Oil Changes, Filter Replacements, Lubrication, Inspections
Troubleshooting:
Diagnostic Procedures, Symptom-Based Troubleshooting Guides, Fault Code Diagnosis
Repair:
Component Removal and Installation, Overhaul Procedures, Adjustment Procedures
Diagnostics:
OBD-I diagnostic codes, component testing, sensor data interpretation for the era.
Engine Rebuild:
Detailed procedures for cylinder head removal, piston and connecting rod installation, crankshaft bearing replacement, camshaft timing.
Transmission Service:
Torque converter replacement, valve body diagnostics, seal replacement, clutch pack inspection.
Electrical System Repair:
Component testing for injectors, fuel pump, ignition coil, starter motor, alternator; wiring harness repair and continuity testing.
Suspension And Steering Repair:
Replacement of control arms, ball joints, tie rods, steering gearbox overhaul, shock absorber replacement, leveling system (if equipped).
Depth:
Comprehensive (from basic maintenance to full engine rebuilds and electrical system diagnostics)
Engine Type:
Inline 6-Cylinder, SOHC
Displacement:
3.0 Liters (2962 cc)
Bore X Stroke:
88.5 mm x 80.25 mm
Horsepower:
188 hp @ 5700 rpm (SAE Net)
Torque:
195 lb-ft @ 4400 rpm (SAE Net)
Fuel Delivery:
Bosch KE-Jetronic CIS-E Fuel Injection
Fuel Type:
Premium Unleaded Gasoline (91 Octane or higher)
Ignition System:
Electronic Ignition with Knock Control
ECU Type:
Bosch Motronic (specific model varies)
NHTSA Front Impact:
N/A (Not tested by NHTSA under current protocols)
IIHS Side Impact:
N/A (Not tested by IIHS under current protocols)
ABS:
Standard (Anti-lock Braking System)
Traction Control:
Optional (ASR - Acceleration Slip Regulation)
Airbags:
Driver's Side Airbag Standard
Seatbelts:
3-Point Inertia-Reel Seatbelts Front & Rear
Crumple Zones:
Yes (Front and Rear)
Audio System:
Factory AM/FM Stereo Cassette Player with optional CD Changer and premium sound system (Becker units common).
Climate Control:
Automatic Climate Control (Klima-automatik) with cabin temperature sensor and adjustable airflow.
Memory Seats:
Optional (Driver and Passenger)
Connectivity Features:
N/A (Analog systems, no integrated Bluetooth or USB)
Oil Change Interval:
Every 5,000-7,500 miles or 6-12 months (depending on driving conditions and oil used)
Major Service Interval:
Refer to manual for specific mileage intervals (e.g., 30k, 60k, 90k miles) for spark plugs, belts, coolant, etc.
Engine Oil Type:
API SG/SH, ACEA A2/A3 (e.g., Mobil 1 15W-40, 10W-30, 5W-30 depending on climate)
Engine Oil Capacity:
7.4 Liters (7.8 US Quarts) with filter change
Coolant Type:
MB Spec 325.0 (Ethylene Glycol based, typically 50/50 mix with distilled water)
Brake Fluid Type:
DOT 3 or DOT 4
Common Wear Items:
Ball joints, tie rod ends, shock absorbers, flex discs, fuel pump relay, idle control valve, climate control vacuum leaks.
Electrical Common Failures:
Door lock actuators, window regulators, instrument cluster warning lights, wiring harness insulation degradation (especially around engine bay).
Engine Maintenance Tips:
Regularly check and replace the fuel distributor O-rings, ensure proper function of the air flow meter, maintain correct CIS pressure.
Brand Reputation:
Renowned for engineering excellence, durability, safety, and luxury.
W126 Generation:
Second generation of the S-Class, representing the pinnacle of Mercedes-Benz engineering in the 1980s.
W126 Facelift:
Significant facelift in 1985, introducing updated styling, engines, and improved aerodynamics.
Production Years W126:
1979-1991
Country Of Origin:
Germany
