🏷️ Basic Information Identification Make: BMW Model: 525 Model Variant: 525i Year: 1981 Codes Chassis Code: E28 👋 Introduction Market Position Segment: Luxury Executive Sedan Target Audience: Professionals, enthusiasts, and owners seeking to maintain and repair their classic BMW sedan Competitive Analysis Key Competitors: Mercedes-Benz W123, Audi 5000, Volvo 240, Jaguar XJ Key Features Driving Dynamics: Renowned for its balanced chassis, precise steering, and comfortable ride, characteristic of BMW's 'Ultimate Driving Machine' ethos Engine Smoothness: The M30 straight-six engine provided strong, smooth power delivery Build Quality: Exceptional build quality and durable engineering typical of BMW vehicles from this era Manual Value Proposition: Essential for owners of this classic vehicle to perform maintenance and repairs, preserving its value and performance. 📋 Manual Details Coverage Areas Engines Covered: M30B25 (2.5L Inline-6) Transmissions Covered: All Automatic and Manual Transmissions Trim Levels Covered: All trim levels of the 1981 BMW 525i Page Count Estimated Pages: 500-800 (typical for comprehensive workshop manuals of this era) Manual Type Type: Workshop Repair Service Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine Mechanical: Engine assembly, disassembly, cylinder head, pistons, crankshaft, camshaft, timing, lubrication system, cooling system Fuel System: Fuel injection (Bosch L-Jetronic), fuel pump, injectors, fuel pressure regulator, fuel lines, fuel tank Ignition System: Distributor, ignition coil, spark plugs, ignition timing, electronic control unit (ECU) Transmission: Manual (Getrag 260), Automatic (ZF 4HP22), clutch, driveshaft, differential Suspension: Front suspension (MacPherson struts), rear suspension (semi-trailing arms), shock absorbers, springs, control arms, sway bars Brakes: Front disc brakes, rear disc brakes, brake system hydraulics, parking brake, ABS (if equipped) Steering: Power steering system, steering rack, steering column, steering wheel Electrical System: Battery, charging system (alternator), starting system (starter motor), lighting system, power windows, central locking, fuses, relays, wiring diagrams Body And Chassis: Body panels, doors, hood, trunk, bumpers, interior trim, chassis components HVAC: Heating, ventilation, and air conditioning (HVAC) system components and operation Procedures Included Routine Maintenance: Oil changes, filter replacements, fluid checks and top-offs, spark plug replacement, belt inspections Troubleshooting: Diagnostic procedures for common starting, running, and system issues; fault code interpretation (where applicable) Repair And Rebuild: Detailed step-by-step instructions for component disassembly, repair, and reassembly (e.g., engine rebuild, transmission overhaul, brake caliper replacement) Diagnostics: Testing procedures for electrical components, fuel system pressures, ignition timing, and sensor outputs Adjustments: Carburetor (if applicable, though 525i typically has injection), idle speed, ignition timing, brake adjustments Technical Depth Depth: Comprehensive, covering everything from basic maintenance to complete engine and transmission overhauls Diagnostic Tools: Information on specialized tools and diagnostic equipment required for specific procedures Torque Specifications: Detailed torque values for critical fasteners across all systems Clearances And Tolerances: Precise specifications for engine component clearances, valve lash, bearing tolerances, etc. 📊 Manual Specifications File Format File Type: PDF Searchability: Likely text-searchable if professionally digitized, otherwise image-based OCR Print Quality Quality: Digital PDF, quality dependent on source scan Binding Type Binding: Not applicable (Digital Download) Paper Type Paper: Not applicable (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Code: M30B25 Engine Type: Naturally Aspirated Inline-6 (Straight-6) Displacement: 2494 cc (2.5 Liters) Bore X Stroke: 84.0 mm x 75.0 mm Compression Ratio: 8.0:1 or 8.8:1 (depending on market/specific variant) Performance Horsepower: 150 PS (148 hp) at 5500 rpm (approximate) Torque: 220 Nm (162 lb-ft) at 3500 rpm (approximate) Fuel System Fuel Delivery: Bosch L-Jetronic Electronic Fuel Injection Fuel Type: Unleaded Gasoline (Premium) Cooling System Type: Liquid-cooled, pressurized Lubrication System Oil Capacity: 6.5 Liters (approx.) 🔧 Transmission Standard Type: Getrag 260 5-Speed Manual Transmission Optional Type: ZF 4HP22 4-Speed Automatic Transmission Features Manual Gear Ratios: 1st: 4.00, 2nd: 2.26, 3rd: 1.41, 4th: 1.00, 5th: 0.81, Reverse: 3.75 (typical for Getrag 260) Automatic Features: Torque converter lock-up in higher gears Fluid Specifications Manual Fluid: GL-4 Hypoid Gear Oil, SAE 75W-90 or 80W-90 Automatic Fluid: BMW ATF Dexron-III (or equivalent) 📐 Dimensions Exterior Length: 4620 mm (181.9 in) Width: 1700 mm (66.9 in) Height: 1410 mm (55.5 in) Wheelbase: 2795 mm (110.0 in) Front Track: 1440 mm (56.7 in) Rear Track: 1470 mm (57.9 in) Weights Curb Weight: 1400-1500 kg (approx.) Gvw: Not specified, but typically around 1900-2000 kg Wheels Tires Wheel Bolt Pattern: 5x120 Typical Tire Size: 195/70VR14 or 205/60VR14 🛡️ Safety Features Ratings Crash Test Data: Data from this era is less standardized than modern tests; focus is on passive safety features. Active Features ABS: Optional Anti-lock Braking System (ABS) on later E28 models, may not be standard on early 1981 525i. Passive Features Seatbelts: Three-point inertia-reel front seatbelts, two-point rear seatbelts Body Construction: Reinforced safety cage, energy-absorbing crumple zones Headrests: Front and rear headrests 💡 Technology Features Infotainment Original System: Basic AM/FM radio with cassette player, often with a separate amplifier and graphic equalizer. Driver Assistance Cruise Control: Optional cruise control system available. Connectivity Original Connectivity: N/A (No modern connectivity...