🏷️ Basic Information

Make:

BMW

Model:

5-series

Model Code:

E12

Year:

1981

Generation Name:

First Generation (E12)

Chassis Code:

E12

👋 Introduction

Market Position:

Premium executive sedan for its era, representing BMW's focus on driving dynamics and luxury.

Competitors:

Mercedes-Benz W123 E-Class, Audi 5000 (Type 43), Volvo 260 Series, Jaguar XJ6.

Key Features:

Rear-wheel drive, independent suspension, sophisticated (for the time) inline-six engines, driver-oriented interior, robust build quality.

Value Proposition:

Provides definitive, factory-authorized repair and maintenance information, empowering owners and independent mechanics to service the E12 accurately and efficiently.

📋 Manual Details

Covered Models:

All BMW 5-series (E12) models for 1981

Repair Scope:

Comprehensive A-Z repairs

Estimated Page Count:

Varies (typical factory manuals for this era are 500-1000+ pages, but digital format allows for flexible delivery)

Manual Type:

Factory Service and Repair Manual

Language:

English

Digital Format:

PDF

Compatibility:

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

Print Capability:

Printable pages and diagrams

📖 Manual Coverage

Engine Systems:

Engine mechanical, fuel system, emission control, intake, exhaust, cooling, lubrication, ignition, starting, charging

Drivetrain Systems:

Automatic transmission, manual transmission, clutch, transfer case (if applicable to specific models), propeller shaft, drive shafts, differential, axles

Suspension Steering Brakes:

Axle, suspension, tire and wheel, brake control, brakes (hydraulic and mechanical), parking brake, steering column, power steering

Electrical Systems:

Wiring schematics, lighting, instruments, audio/visual, horn, multiplex/CAN communication (early forms), cruise control, engine immobilizer (if factory fitted)

Body Interior Features:

Air conditioning, supplemental restraint system (airbags, if equipped), seat belts, wipers and washers, door locks, meter/instrument panel, seats, engine hood/doors, exterior and interior trim, windshield/glass/mirrors

Diagnostic Procedures:

Detailed diagnostic procedures for all systems

Repair Procedures:

Step-by-step repair instructions for all components and systems

Maintenance Procedures:

Scheduled maintenance, fluid changes, filter replacements, component inspections

Troubleshooting Guides:

Troubleshooting charts and guides for common issues

Technical Depth:

Factory-level diagnostic, service, and repair information

Detail Level:

Highly detailed, specific to the E12 chassis and its components

Visual Aids:

Diagrams, illustrations, wiring schematics

📊 Manual Specifications

File Format:

PDF

Searchability:

Likely text-searchable within the PDF

Print Quality:

High-resolution, suitable for clear printing of text and diagrams

Diagram Scalability:

Images can be blown up for enlarged printed copies

Binding Type:

N/A (Digital PDF format)

Paper Type:

N/A (Digital PDF format, user prints on desired paper)

Software Requirements:

Adobe PDF Reader, Winzip (or equivalent unzipping software)

Download Speed:

Fast download

⚙️ Engine Specifications

Engine Options 1981:

Primarily M30 inline-six engines: 520i (2.0L), 525i (2.5L), 528i (2.8L).

Typical Hp 528I:

Approx. 168-175 hp (depending on market and specific tuning)

Typical Torque 528I:

Approx. 210-220 Nm (155-162 lb-ft)

Fuel Injection:

Bosch L-Jetronic or K-Jetronic fuel injection (depending on model and market)

M30 Engine Code:

M30

Cooling Type:

Pressurized liquid cooling system

Oil Capacity M30:

Approximately 5.5 liters (5.8 US quarts) with filter change

🔧 Transmission

Standard Transmission:

4-speed manual transmission

Optional Transmission:

3-speed or 4-speed ZF automatic transmission (model dependent)

Clutch Type:

Hydraulically operated single-plate dry clutch

Manual Transmission Fluid:

Hypoid gear oil, SAE 90 (e.g., BMW part number 81 22 9 407 799 or equivalent)

Automatic Transmission Fluid:

Dexron II or equivalent (e.g., BMW part number 81 22 9 400 275 or equivalent)

📐 Dimensions

Wheelbase:

Approx. 2795 mm (110.0 inches)

Length:

Approx. 4620 mm (181.9 inches)

Width:

Approx. 1700 mm (66.9 inches)

Height:

Approx. 1420 mm (55.9 inches)

Curb Weight:

Approx. 1350-1450 kg (2976-3197 lbs), depending on engine and equipment

Trunk Capacity:

Approx. 450 liters (15.9 cubic feet)

🛡️ Safety Features

Safety Ratings:

N/A (Modern crash test standards were not prevalent or standardized in 1981)

Passive Safety Features:

Reinforced passenger cell, crumple zones, padded dashboard, three-point seat belts (front), two-point seat belts (rear, often optional or lap belts)

Active Safety Features:

Four-wheel disc brakes (ventilated front), independent suspension, power-assisted steering (optional), limited-slip differential (optional on some models)

💡 Technology Features

Infotainment Features:

Basic analog radio (AM/FM), optional cassette player, analog gauges.

Driver Assistance Features:

Power steering (optional), cruise control (optional on some models).

Connectivity Features:

N/A (No modern connectivity features like Bluetooth or USB).

Lighting Technology:

Halogen headlights, standard incandescent lighting for turn signals and taillights.

🔧 Maintenance

Oil Change Interval:

Typically every 5,000-7,500 miles or 6-12 months (refer to specific manual for exact mileage/time).

Spark Plug Replacement:

Every 15,000-30,000 miles (depending on spark plug type - conventional vs. platinum).

Coolant Flush Interval:

Every 2 years or 30,000 miles.

Engine Oil Specification:

API SG or SF rated, SAE 10W-40 or 20W-50 (viscosity dependent on climate). BMW recommended Castrol GTX or equivalent.

Brake Fluid Specification:

DOT 3 or DOT 4 hydraulic brake fluid (e.g., BMW part number 81 22 9 407 885 or equivalent).

Coolant Specification:

Ethylene glycol-based antifreeze, mixed 50/50 with distilled water. BMW Blue or Green coolant (BMW part number 81 22 9 407 454 or equivalent).

Common Issues E12:

Rust (wheel arches, sills, subframes), fuel distributor leaks (K-Jetronic), vacuum hose deterioration, cooling system leaks (hoses, radiator), wear on front suspension bushings, potential for overheating if cooling system is not maintained.

Oil Filter Part Number Example:

Mann-Filter W940/1 or equivalent (verify for specific engine)

Air Filter Part Number Example:

Mann-Filter C2566 or equivalent (verify for specific engine)

📚 Vehicle History

Brand Heritage:

BMW's reputation for engineering excellence, performance, and luxury vehicles.

E12 Introduction:

Introduced in 1972 as BMW's first mid-size executive sedan, replacing the BMW E3 (New Six) sedan in its segment. The E12 was a significant model for BMW, establishing its presence in this class.

E12 Facelift:

Received a significant facelift in 1977 (often referred to as the E12 LCI or 'facelift' models), which included revised front and rear styling, improved aerodynamics, and updated interior features. The 1981 model year falls within this facelifted period.

Production Period E12:

1972-1981

Successors:

Succeeded by the BMW E28 5-series.

🏆 Awards & Recognition

Historic Acclaim:

The E12 was widely praised for its driving dynamics and build quality, contributing significantly to BMW's reputation as a leading automotive manufacturer.

Period Reviews:

Contemporary reviews often highlighted the chassis balance, responsive engines, and premium interior for its class.

Certifications:

N/A (Certification standards were different in the early 1980s).