🏷️ Basic Information

Make:

BMW

Model:

3 Series

Chassis Code:

E21

Model Year:

1981

Engine Codes Covered:

M10 variants (e.g., M10B18, M10B20), M20 variants (e.g., M20B23)

👋 Introduction

Market Position:

Essential reference for BMW E21 owners and independent workshops, providing dealership-level technical information for a classic German sports sedan.

Target Audience:

BMW E21 owners with basic mechanical skills, DIY enthusiasts, and professional independent auto service technicians.

Competitive Analysis:

Offers specific, manufacturer-provided data for the E21 generation, distinguishing it from generic repair guides. Emphasizes vehicle-specific accuracy for effective maintenance and repair.

Key Features:

Step-by-step instructions, detailed diagrams and illustrations, wiring schematics, comprehensive troubleshooting, vehicle-specific specifications, dealer-level accuracy.

Illustrations Diagrams:

Abundant illustrations and clear diagrams to visually guide the user through complex repair procedures, enhancing understanding and accuracy.

📋 Manual Details

Coverage Areas:

All major topics including General Information, Engine Mechanical, Engine Electrical, Emission Control, Fuel System, Clutch, Manual Transaxle, Automatic Transaxle, Driveshaft & Axle, Suspension, Steering, Restraint Systems, Brake System, Body (Interior/Exterior), Body Electrical System, HVAC

Page Count:

Not Specified (Implied to be comprehensive)

Manual Type:

Service Repair Workshop Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Systems Covered:

Engine mechanical (including timing, cylinder head, block, lubrication), Engine electrical (ignition, starting, charging), Emission control systems, Fuel injection and carburetion systems, Clutch operation and repair, Manual and automatic transmission systems, Drivetrain components (driveshaft, differential, axles), Suspension geometry and components, Steering mechanism and linkages, Brake system hydraulics and mechanics, Bodywork (exterior panels, interior trim), Body electrical (lighting, power accessories, instrumentation), HVAC system (heating, ventilation, air conditioning)

Restraint System Coverage:

Details on seat belt systems, including pre-tensioners (if applicable to specific models/markets) and adjustment mechanisms.

Brake System Coverage:

Front disc brakes and rear drum brakes (or disc brakes on some higher-performance variants), including brake caliper/wheel cylinder overhaul, pad/shoe replacement, fluid bleeding, and parking brake adjustment.

Body Electrical System:

Covers headlights, taillights, interior lighting, dashboard instruments, wipers, horn, and accessory electrical circuits.

Procedures Included:

Step-by-step repair instructions, troubleshooting guides, diagnostic procedures, maintenance schedules, component removal and installation, adjustment procedures, wiring schematic interpretation, torque specifications, fluid capacities and types, electrical system diagnostics

Body Repair Procedures:

Instructions for body panel alignment, rust repair techniques, interior trim removal and installation, and exterior component replacement.

Diagnostic Procedures:

Systematic troubleshooting steps for diagnosing mechanical, electrical, and fuel system issues, including symptom-based troubleshooting.

Component Rebuild Procedures:

Detailed procedures for rebuilding major components like engines, transmissions, brake calipers, and steering racks.

Troubleshooting Guides:

Structured troubleshooting sections based on symptoms, guiding users to identify and resolve common automotive problems efficiently.

Technical Depth:

Comprehensive; suitable for basic maintenance to advanced diagnostics and repairs, equivalent to dealer-level technician resources.

Wiring Schematic Detail:

Includes comprehensive, easily interpretable wiring diagrams for all major electrical systems, aiding in diagnosis and repair of circuits.

Torque Specifications:

Includes specific torque values for critical engine, chassis, and suspension fasteners, ensuring correct assembly and preventing component damage.

📊 Manual Specifications

File Format:

PDF (Portable Document Format)

Digital Compatibility:

Viewable on PC, Mac, and various devices including phones and e-readers with PDF reader capability.

Print Quality:

Printable pages allowing for high-quality reproduction of diagrams and text.

Binding Type:

Digital (Printable PDF)

Paper Type:

N/A (Digital Format - Printable)

⚙️ Engine Specifications

Primary Engine:

M10 4-cylinder (various displacements like 1.8L, 2.0L) and M20 6-cylinder (e.g., 2.3L) engines.

Performance Data:

Covers engine variants producing approximately 90-105 HP for 4-cylinder and 105-140 HP for 6-cylinder models, detailing adjustments for optimal performance.

Fuel System:

Carbureted (e.g., Solex, Zenith) and early Bosch L-Jetronic fuel injection systems, with detailed diagnostic and repair procedures for both.

Fuel System Carburetor Details:

In-depth information on carburetor models used, including adjustment procedures, idle speed settings, and troubleshooting fuel delivery.

Fuel System Injection Details:

Troubleshooting and repair for Bosch L-Jetronic fuel injection, including sensor testing, injector diagnostics, and fuel pump checks.

Engine Mechanical System:

Covers cylinder head, valve train, piston assemblies, crankshaft, connecting rods, lubrication system, cooling system, and timing components.

Engine Electrical System:

Covers ignition system (distributor, coil, spark plugs), starting system (starter motor, solenoid), charging system (alternator, voltage regulator), and engine sensors.

Emission Control System:

Details on emission control components such as air pumps, EGR valves (if applicable), catalytic converters (later models), and fuel vapor control systems.

🔧 Transmission

Standard Transmission:

4-speed and 5-speed manual transmissions (e.g., Getrag 245).

Optional Transmission:

3-speed ZF automatic transmission.

Transmission Features:

Details on clutch operation, manual gearbox overhaul, automatic transmission servicing, and driveshaft/axle maintenance.

Manual Transaxle System:

Detailed overhaul and repair procedures for manual gearboxes, including gear selection mechanisms and bearing replacements.

📐 Dimensions

Exterior Dimensions:

Detailed dimensions for sedan body style, wheelbases, and track widths specific to the E21 chassis.

Curb Weight:

Approximate curb weights ranging from 1100-1300 kg depending on engine and options.

Suspension System:

Covers front and rear suspension components, including struts, control arms, bushings, shock absorbers, and wheel bearings, along with alignment specifications.

Steering System:

Details on the steering gearbox, tie rods, steering column, and power steering assist system (if equipped).

🛡️ Safety Features

Safety Ratings:

Covers passive safety features and structural integrity relevant to 1980s vehicle safety standards. No modern crash test data available.

Passive Features:

Seat belts, reinforced chassis structure, collapsible steering column, padded interior surfaces.

💡 Technology Features

Infotainment Features:

Basic radio systems with analog tuning, speaker configurations typical for the era.

Driver Assistance Features:

Limited to basic driver aids like power steering (where equipped) and standard braking systems; no electronic driver assistance features found in modern vehicles.

Connectivity Features:

No electronic connectivity features as understood in modern vehicles. Manual covers basic vehicle electrical systems.

🔧 Maintenance

Service Intervals:

Details common service intervals for oil changes (e.g., 5,000-7,500 miles), filter replacements, spark plug changes, and brake inspections.

Spark Plug Replacement Interval:

Typically every 15,000-20,000 miles, depending on spark plug type and engine condition.

Air Filter Replacement Interval:

Every 15,000-30,000 miles or as needed based on driving conditions.

Fluid Specifications:

Specifies engine oil types (e.g., SAE 20W-50, 10W-40), coolant type, brake fluid DOT specification (e.g., DOT 3), transmission fluid, and differential oil recommendations.

Cooling System Fluid:

BMW recommended coolant mixture (e.g., ethylene glycol based antifreeze with distilled water).

Brake Fluid Specification:

DOT 3 or DOT 4 brake fluid.

Transmission Fluid Manual:

GL-4 or GL-5 gear oil (specific viscosity varies by temperature, e.g., 75W-90).

Transmission Fluid Automatic:

Dexron-III or equivalent ATF fluid.

Differential Fluid:

GL-5 gear oil (e.g., 75W-90).

Known Issues:

Common E21 issues covered may include fuel delivery problems, ignition system faults, rust susceptibility (especially in wheel wells and sills), cooling system leaks, and suspension wear.

📚 Vehicle History

Brand Heritage:

BMW's reputation for sporty sedans and driver-focused engineering, building on the success of the 02 Series.

Model Evolution:

The first generation of the 3 Series, introduced in 1975 as a successor to the 02 Series, evolving into the iconic E21.

E21 Key Innovations:

Introduction of the McPherson strut front suspension, rack-and-pinion steering, and a more integrated chassis design compared to its predecessor.

Production Years:

1975-1982 (model year 1981 falls within this range).

Manufacturing Locations:

Primarily Germany (Munich, Dingolfing).