🏷️ Basic Information Identification Make: BMW Model: 520i Year: 1991 Codes Chassis Code: E34 Engine Code: M50B20 👋 Introduction Market Position Segment: Executive sedan, premium mid-size Target Audience: Owners seeking to perform their own maintenance and repairs, independent repair shops specializing in BMW vehicles. Competitive Analysis Competitors 1991: Mercedes-Benz W124 E-Class, Audi 100/200, Lexus LS 400 (introduced late 1989, gaining traction), Jaguar XJ Key Features Vehicle Attributes: Renowned BMW handling ('Ultimate Driving Machine'), refined inline-six engines, robust build quality, comfortable and luxurious interior. Manual Value Proposition Value: Provides authoritative guidance for maintaining and repairing a classic BMW, enabling cost savings and preserving vehicle integrity. 📋 Manual Details Coverage Areas Main Topics: Full service and repair instructions Page Count Estimated Page Count: Approx. 800-1200 pages (typical for comprehensive BMW E34 manuals) Manual Type Type: Service Repair Workshop Manual Language Language: English Format Format: Digital (likely PDF) 📖 Manual Coverage Systems Covered Engine: Engine mechanical, engine management, cooling, lubrication, fuel delivery, ignition system Transmission: Manual and automatic transmission overhaul, repair, and adjustment Drivetrain: Driveshafts, differential, axles, clutch Suspension: Front and rear suspension components, steering system, wheel alignment Brakes: Brake system components, ABS (if equipped), hydraulic system, disc/drum brake service Electrical: Wiring diagrams, starter, alternator, battery, lighting, instrumentation, power accessories, fuse/relay locations Body: Body panels, doors, windows, interior trim, bumpers, chassis adjustments Heating And Ac: HVAC system components, refrigerant handling, climate control Procedures Included Maintenance: Scheduled maintenance, oil changes, filter replacements, tune-ups Troubleshooting: Diagnostic procedures, symptom-based troubleshooting guides, fault code interpretation Repair: Component removal and installation, rebuilding procedures, adjustments Specifications: Torque specifications, clearances, fluid capacities, electrical values Technical Depth Depth: Comprehensive, covering basic maintenance to complete engine and transmission rebuilds, diagnostic procedures for all major systems. 📊 Manual Specifications File Format File Type: PDF Searchable Text: Likely searchable (depending on OCR quality) Print Quality Image Resolution: High-resolution scans expected for diagrams and illustrations Binding Type Binding: N/A (Digital Format) Paper Type Paper: N/A (Digital Format) ⚙️ Engine Specifications Primary Engine Engine Type: Inline 6-cylinder, DOHC, 24-valve Displacement: 1991 cc (2.0 Liters) Bore X Stroke: 80.0 mm x 66.0 mm Compression Ratio: 8.8:1 Performance Horsepower: 129 hp @ 5500 rpm (approximate DIN) Torque: 180 Nm (133 lb-ft) @ 4300 rpm (approximate DIN) Fuel System Fuel Delivery: Bosch Motronic M2.1 or M2.5 Electronic Fuel Injection (EFI) Fuel Type: Unleaded gasoline (RON 95 recommended) Ignition System Ignition Type: Distributorless ignition (DIS) or distributor with coil packs managed by Motronic ECU Cooling System Coolant Type: BMW Blue Antifreeze/Coolant or equivalent G48 ethylene glycol-based coolant Lubrication System Oil Type: SAE 15W-40 or 10W-40 API SG/SH or higher (check manual for specific BMW approval) Oil Capacity: Approx. 4.5 - 5.0 liters (with filter) 🔧 Transmission Standard Type: Getrag 260 5-speed manual transmission Optional Type: ZF 4HP22 4-speed automatic transmission Features Manual Gear Ratios: 1st: 4.07, 2nd: 2.21, 3rd: 1.40, 4th: 1.00, 5th: 0.81 (typical) Fluid Specifications Manual Transmission Fluid: SAE 75W-90 API GL-4 or GL-5 gear oil (check manual for specific type) Automatic Transmission Fluid: ATF Dexron II or III (check manual for exact specification) 📐 Dimensions Exterior Length: 4710 mm (185.4 in) Width: 1751 mm (68.9 in) Height: 1410 mm (55.5 in) Wheelbase: 2799 mm (110.2 in) Weights Curb Weight: Approx. 1450-1550 kg (3197-3417 lbs) Gross Vehicle Weight: Approx. 1950 kg (4299 lbs) Wheels And Tires Wheel Bolt Pattern: 5x120 Wheel Size: 15-inch or 16-inch alloy wheels (common) Tire Size: 205/60R15 or 225/55R15 (common) 🛡️ Safety Features Ratings Crash Test Results: NCAP or IIHS ratings for this era are not as standardized or readily available as modern vehicles. Focus on passive safety features. Active Features ABS: Anti-lock Braking System (optional on early E34, standard on later models) Traction Control: Automatic Stability Control (ASC) or Automatic Stability Control + Traction (ASC+T) was an option on higher-spec E34 models, less common on the 520i. Passive Features Airbags: Driver's side airbag (optional or standard depending on market and production date, not universally standard for 1991) Seatbelts: 3-point inertia-reel seatbelts front and rear Body Structure: Reinforced safety cage, crumple zones. 💡 Technology Features Infotainment Radio: Factory BMW AM/FM stereo with cassette player, often with optional CD changer provisions. Onboard Computer: Optional On-Board Computer (OBC) displaying fuel consumption, range, average speed, and diagnostic codes. Driver Assistance Cruise Control: Standard or optional cruise control system. Comfort Features Climate Control: Manual or optional automatic climate control (ACC - Automatic Climate Control). Windows And Mirrors: Power windows, power adjustable mirrors. Optional heated mirrors. 🔧 Maintenance Service Intervals Oil Change Interval: Every 7,500 - 10,000 miles or 12 months (whichever comes first), depending on driving conditions. Check manual for BMW's specific recommendations for this model year. Spark Plug Replacement: Typically every 30,000 - 60,000 miles, depending on spark plug type (standard copper vs. long-life) Coolant Flush: Every 2-3 years or 30,000-40,000 miles. Timing Belt Or Chain: The...