🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W126 SE

Year:

1986

Chassis Code:

W126

Body Style:

SE (Special Edition/Sedan)

👋 Introduction

Target Audience:

Mercedes-Benz W126 SE owners, DIY mechanics, and automotive repair shops seeking accurate, factory-level repair data.

Value Proposition:

Provides the same essential information used by dealership technicians, empowering users to perform maintenance and repairs effectively and cost-efficiently.

Advantage:

Offers vehicle-specific, factory-level detail, unlike generic repair manuals. Digital format provides convenience, portability, and cost savings over physical manuals.

Feature 1:

Complete A-Z repair coverage for the 1986 W126 SE.

Feature 2:

Vehicle-specific information, not generic.

Feature 3:

Includes step-by-step instructions, diagrams, illustrations, and wiring schematics.

Feature 4:

Digital PDF format for easy access, searchability, and selective printing.

Feature 5:

Compatible with both Windows and Mac operating systems.

📋 Manual Details

Primary Coverage:

1986 Mercedes-Benz W126 SE

Additional Coverage:

All W126 SE models and variations for the specified year.

Estimated Page Count:

Comprehensive (exact count not specified, but described as 'everything you will ever need')

Type:

Service and Repair Manual

Language:

English

Format:

PDF (Printable)

📖 Manual Coverage

Engine Mechanical:

Detailed repair and overhaul procedures for the engine, including cylinder head, block, crankshaft, pistons, and timing systems.

Engine Control System:

Diagnosis and repair of fuel injection (e.g., Bosch K-Jetronic or KE-Jetronic depending on specific engine), ignition timing, and electronic control units (ECU).

Fuel System:

Service and specifications for fuel pumps, injectors, fuel lines, fuel pressure regulators, and fuel tank.

Emission Control:

Information on emission control systems, including catalytic converters, EGR (Exhaust Gas Recirculation), and secondary air injection (if applicable).

Cooling System:

Maintenance, diagnosis, and repair of the radiator, coolant pump, thermostat, hoses, and climate control integration.

Lubrication System:

Oil change procedures, oil filter replacement, oil pressure testing, and lubrication specifications.

Ignition Starting Charging:

Detailed procedures for spark plugs, ignition coils, distributor (if applicable), starter motor, and alternator testing and replacement.

Automatic Transmission:

Service, repair, and diagnosis of the automatic transmission, including fluid changes, filter replacement, and torque converter service.

Manual Transmission:

Service and repair for manual transmissions (less common for SE models but potentially covered depending on variant).

Drive Shaft Differential:

Maintenance and repair of the driveshaft, universal joints, differential, and axle shafts.

Suspension Steering:

Detailed information on front and rear suspension components, shock absorbers, springs, bushings, and steering system (including power steering).

Brakes:

Service for hydraulic brake systems, including master cylinder, brake lines, calipers, pads, rotors, and ABS (Anti-lock Braking System) diagnosis and repair.

Parking Brake:

Adjustment and repair of the parking brake system.

Body Electrical:

Comprehensive coverage of the vehicle's electrical system, including lighting, power windows, door locks, mirrors, and interior electronics.

Climate Control:

Service and repair of the air conditioning system, heater core, blower motor, and climate control modules.

Safety Restraint Systems:

Information on seat belts and Supplemental Restraint Systems (SRS), including airbags (if applicable to 1986 models).

Instrumentation Gauges:

Diagnosis and repair of the instrument cluster, gauges, warning lights, and trip computer.

Interior Trim Seats:

Procedures for removing and reinstalling interior trim panels, seats, and headliner.

Exterior Body:

Information on doors, hood, trunk, bumpers, fenders, and glass replacement.

Wiring Schematics:

Complete and detailed wiring diagrams for all electrical systems, crucial for accurate diagnostics.

Preventative Maintenance:

Routine checks, fluid level adjustments, filter replacements, belt inspections, and tune-up procedures.

Troubleshooting Diagnostics:

Systematic diagnostic procedures for identifying faults, including symptom-based troubleshooting and fault code interpretation (if applicable).

Component Repair Overhaul:

Step-by-step instructions for disassembling, repairing, and reassembling major vehicle components.

Replacement Procedures:

Detailed guides for replacing worn or damaged parts, from minor components to major assemblies.

Adjustment Calibration:

Procedures for adjusting systems like engine idle speed, parking brake, and suspension height.

Installation Procedures:

Instructions for installing new or replacement parts and systems.

Depth:

Factory-level, highly detailed. Covers everything from basic maintenance to complex repairs and diagnostics.

Completeness:

Vehicle-specific and complete A-Z repair coverage, not generic information.

Illustrations Diagrams:

Includes step-by-step illustrations, diagrams, and visual aids to clarify repair procedures.

Specifications Data:

Provides essential technical specifications, torque values, fluid capacities, and performance data.

📊 Manual Specifications

Format:

PDF

Compatibility:

Windows Vista (32/64), XP, ME, 98, NT, 2000, and Mac compatible.

Requirements:

Adobe PDF Reader and Winzip (free online).

Printability:

All pages are printable, with the ability to enlarge images for clarity.

Binding:

Digital (PDF), eliminating physical binding issues.

Paper Type:

Not applicable (digital format).

⚙️ Engine Specifications

Engine Type:

V8 Gasoline (likely M116 or M117 engine family for SE models in 1986)

Engine Displacement Liters:

Likely 3.8L (M116) or 5.0L (M117) for SE models, precise displacement depends on specific engine code within W126 SE designation.

Fuel Delivery:

Bosch K-Jetronic or KE-Jetronic fuel injection system.

Horsepower Range Hp:

Typically 150-200 HP, depending on engine displacement and specific market tuning.

Torque Range Lb Ft:

Approximately 200-250 lb-ft, depending on engine displacement.

Fuel Type:

Unleaded gasoline (as per 1986 emissions regulations).

Fuel Pump Spec:

Specific part numbers and pressure specifications will be detailed within the manual.

🔧 Transmission

Type:

4-speed Automatic Transmission (e.g., 722.3 or 722.4)

Type:

Manual transmission was very rarely offered on W126 SE models, primarily on earlier or specific international variants.

Fluid Type:

Specific Mercedes-Benz approved automatic transmission fluid (e.g., MB 236.1, MB 236.2, or MB 236.3, depending on transmission build).

Fluid Capacity Liters:

Approximately 7-8 liters for a complete fill, but specific procedures for checking and filling will be in the manual.

📐 Dimensions

Wheelbase Mm:

Approximately 2935 mm (115.6 inches)

Length Mm:

Approximately 4995 mm (196.7 inches)

Width Mm:

Approximately 1790 mm (70.5 inches)

Height Mm:

Approximately 1425 mm (56.1 inches)

Curb Weight Kg:

Varies by engine and equipment, typically around 1600-1750 kg (3527-3858 lbs).

Gross Vehicle Weight Rating Kg:

Specific GVWR will be detailed in the manual, typically around 2100-2200 kg.

Wheel Bolt Pattern:

5x112 mm

Tire Sizes:

Commonly 195/65R15, 205/60R15, or 215/55R15 depending on trim and options. Specifics in manual.

🛡️ Safety Features

Crash Test History:

While official NHTSA ratings from this era are not always directly comparable to modern standards, the W126 was renowned for its robust construction and safety features for its time.

ABS:

Anti-lock Braking System (ABS) was available, and its diagnosis and repair are covered.

Traction Control:

ASR (Acceleration Slip Regulation) became available later in the W126 lifecycle, less common on 1986 models but potentially covered for specific VINs.

Airbags:

Driver-side airbag became optional and increasingly common during this period, and its system is detailed.

Seat Belts:

3-point inertia-reel seat belts for front and rear occupants, with detailed adjustment and repair information.

Crumple Zones:

Engineered with advanced crumple zones for occupant protection.

💡 Technology Features

Audio System:

Factory-installed radio/cassette players, often with advanced features for the time. Manual covers removal, installation, and troubleshooting of audio components.

Instrumentation:

Sophisticated instrument cluster with analog gauges, warning lamps, and potentially an onboard computer (check control system).

ABS:

Anti-lock Braking System (ABS) was a significant safety technology for its era, with detailed diagnostic procedures in the manual.

Cruise Control:

Standard or optional cruise control system, with troubleshooting information for the vacuum or electronic control unit.

Multiplex Can Communication:

While not CAN bus in the modern sense, W126 vehicles of this era utilize multiplexing and diagnostic buses for various electronic control units. The manual covers these communication systems.

🔧 Maintenance

Oil Change Interval Km Miles:

Typically every 10,000 km (6,000 miles) or 12 months, but precise recommendations are in the manual based on driving conditions.

Major Service Interval Km Miles:

Key services around 40,000-60,000 km (25,000-37,500 miles) including spark plug replacement, fluid flushes, and belt inspections.

Transmission Fluid Service Interval Km Miles:

Recommended every 50,000-80,000 km (30,000-50,000 miles) for automatic transmissions, though debated; manual specifies official intervals.

Engine Oil Type:

API SG or higher, SAE 10W-40 or 15W-40 recommended for general use; specific viscosity depends on ambient temperature. Refer to manual for precise MB specifications.

Coolant Type:

Mercedes-Benz approved coolant (e.g., G40 or similar ethylene glycol-based coolant with corrosion inhibitors for aluminum engines).

Brake Fluid Type:

DOT 3 or DOT 4 hydraulic brake fluid.

Wiring Harness Degradation:

As with many vehicles of this era, wiring insulation can degrade over time, leading to electrical issues. Manual covers diagnosis.

Fuel Injector Leaks:

Rubber seals on fuel injectors can deteriorate, causing leaks and starting issues. Manual details replacement.

Climate Control Actuators:

Vacuum-operated climate control actuators can fail, leading to air flow problems. Manual provides diagnostic and repair procedures.

Suspension Bushings:

Rubber bushings in the suspension and subframes can wear out, causing noise and poor handling. Manual details replacement.

📚 Vehicle History

Manufacturer:

Mercedes-Benz, a globally recognized luxury and automotive engineering leader.

W126 Introduction:

The W126 chassis was introduced in 1979 as the successor to the W116 S-Class, setting new benchmarks in automotive luxury, safety, and engineering.

W126 Features:

Known for its aerodynamic styling, advanced safety features, sophisticated independent suspension, and refined interiors.

1986 Updates:

The 1986 model year falls within the facelifted W126 series (introduced in 1981/1982), which featured updated styling, improved aerodynamics, and further technological enhancements, including potential availability of KE-Jetronic fuel injection and airbags.

Production Years:

W126 S-Class produced from 1979 to 1991.

Manufacturing Location:

Germany (primary), with assembly in other global locations.