🏷️ Basic Information Identification Make: BMW Model: 3 Series / M3 Chassis Code: E30 Model Year Covered: 1990 Codes Engine Codes Covered: M20B25, M20B27 (e.g., 325i, 325is, 325e, 325es, M3) 👋 Introduction Market Position Target Audience: Professional BMW technicians, independent repair shops, and dedicated enthusiasts undertaking complex maintenance and repairs on the E30 platform. Competitive Analysis Value Proposition: Offers definitive, OEM-level information, ensuring accuracy and completeness far beyond generic aftermarket guides. Critical for preserving the integrity and performance of these classic BMWs. Key Features Accuracy: Vehicle-specific, not generic. Directly from BMW's technical documentation. Comprehensiveness: Covers all models and every conceivable repair 'A-Z'. Diagnostic Tools Reference: Likely references BMW-specific diagnostic tools and procedures of the era (e.g., basic scan tools, multimeter use). 📋 Manual Details Coverage Areas Primary Coverage: Comprehensive service and repair procedures for all 1990 BMW 3-Series (E30) and M3 (E30) models. Page Count Estimated Page Count: Extensive; typically 1000+ pages for complete factory-level documentation. Manual Type Type: Service and Repair Manual Language Language: English Format Format: Likely printed or a high-quality PDF reproduction of the original factory manual. 📖 Manual Coverage Systems Covered Powertrain: Engine mechanical, fuel system, ignition system, exhaust system, engine management (DME), cooling system, lubrication system. Drivetrain: Manual and automatic transmissions, clutch, driveshafts, differential, axles. Chassis: Suspension (front and rear), steering system, braking system (including ABS), wheels and tires. Electrical: 12V electrical system, battery, charging system, starting system, lighting, instruments and gauges, fuse and relay box, engine control modules, body electrical. Body: Body construction, exterior panels, doors, windows, interior trim, HVAC system, body seals. Procedures Included Maintenance: Scheduled maintenance intervals, fluid level checks, filter replacements, lubrication. Troubleshooting: Diagnostic flowcharts for common drivability, electrical, and mechanical issues. Repair: Step-by-step repair procedures for all major components and systems, including engine rebuild, transmission overhaul, brake caliper replacement, suspension component renewal. Diagnostics: Engine diagnostics (e.g., checking sensor readings via DME), electrical system testing, pressure testing. Specifications: Torque specifications, clearances, fluid capacities, electrical resistance values, diagnostic trouble codes (DTCs). Technical Depth Depth: Factory-level detail, suitable for professional technicians and advanced DIY enthusiasts. Covers complete overhauls, component-level diagnostics, and calibration procedures. 📊 Manual Specifications File Format Digital Format Considerations: Searchable text, high-resolution diagrams, printable pages. Original factory manuals are often scanned, so quality can vary but is generally excellent for understanding procedures. Print Quality Print Quality Considerations: Paper type is typically durable, designed for workshop environments. Diagrams are clear and legible. Binding Type Binding Type Considerations: Originals often coil-bound or perfect-bound for durability. Recreations may vary. Paper Type Paper Type Considerations: Often on a matte finish paper to reduce glare in workshop lighting. ⚙️ Engine Specifications Primary Engine Engine Options E30 1990: M20 inline-six cylinder, 2.5L (152 cu in) for 325i/is, and potentially the M20 inline-six, 2.7L (164 cu in) for earlier 325e/es models still in service. Performance 325I Horsepower: Approximately 168-171 hp (SAE net) depending on market and specific configuration. 325I Torque: Approximately 215 Nm (159 lb-ft) at 4750 rpm for the 2.5L M20. M3 E30 Engine: S14 inline-four cylinder, 2.3L (140 cu in). High-revving, DOHC, 16-valve engine derived from the M10 block with a unique DOHC head. M3 E30 Horsepower: Approximately 192-200 hp (SAE net) for standard Euro/US spec models. M3 E30 Torque: Approximately 230-240 Nm (170-177 lb-ft) at 4750 rpm for the 2.3L S14. Fuel System Fuel Injection: Bosch Motronic electronic fuel injection (EFI). Fuel Type: Unleaded gasoline (premium octane recommended). Maintenance Timing Belt M20: Recommended replacement every 30,000-40,000 miles or 3-4 years. Critical for preventing catastrophic engine damage. Valve Adjustment S14: Requires periodic valve lash adjustment (shimming) due to the S14's valvetrain design. 🔧 Transmission Standard Standard Transmission Type: Getrag 260 5-speed manual transmission. Optional Optional Transmission Type: ZF 4HP22 4-speed automatic transmission. Features Transmission Fluid Spec: Manual: BMW MTF LT-2 or equivalent. Automatic: ATF Dexron II or III. Clutch Type: Hydraulically actuated single dry plate clutch. 📐 Dimensions Exterior Wheelbase E30: Approx. 2568 mm (101.1 inches). Length E30: Approx. 4340 mm (170.9 inches) for Sedan/Coupe, slightly different for Convertible. Width E30: Approx. 1675 mm (65.9 inches). Height E30: Approx. 1380 mm (54.3 inches). Weights Curb Weight E30 325I: Approx. 1350-1400 kg (2976-3086 lbs). Curb Weight M3 E30: Approx. 1200-1260 kg (2646-2778 lbs). Wheel Bolt Pattern: 5x120 mm. Wheel Offset: Typically ET12 to ET20 depending on wheel size and model. 🛡️ Safety Features Ratings Crash Testing Era: Safety standards of the late 1980s; E30s feature a reinforced passenger cell, crumple zones, and safety glass. Active Features ABS: Anti-lock Braking System (ABS) was optional on most 3-Series models and standard on the M3. Passive Features Seatbelts: Three-point inertia-reel seatbelts front and rear. Steering Column: Collapsible steering column. Fuel Tank Placement: Safely positioned in the rear of the vehicle. 💡 Technology Features Infotainment Audio System: Factory cassette player with optional CD changer integration. Basic AM/FM radio. Climate Control: Manual...