This comprehensive service and repair manual covers all models of the 1981 BMW 5-series (E12) and provides detailed instructions for all repairs, making it an indispensable resource for both experienced mechanics and DIY enthusiasts.

The manual includes step-by-step instructions, diagrams, illustrations, wiring schematics, and specifications necessary to diagnose, maintain, and repair your vehicle. You'll find everything from routine maintenance procedures to complex engine rebuilds, covering every aspect of your BMW.

The manual's user-friendly format allows you to easily locate the information you need. Each section is organized systematically, and clear diagrams and illustrations complement the text. You can print only the pages and diagrams you need, eliminating the need to carry around bulky printed manuals.

The manual's comprehensive coverage includes:

* **Maintenance:** This section details all aspects of routine maintenance, including oil changes, filter replacements, fluid checks, and general inspections, ensuring your vehicle runs smoothly and reliably.
* **Engine:** Understand your engine inside and out, from basic tune-ups to major repairs, including cylinder head work, valve adjustments, and troubleshooting common engine problems.
* **Control System:** Discover the intricacies of your car's control systems, covering fuel injection, ignition, and emission control, allowing you to diagnose and address any issues with confidence.
* **Mechanical:** Delve into the complexities of your vehicle's mechanical systems, including the transmission, clutch, suspension, axles, and more, equipping you to handle a wide range of repairs.
* **Fuel Service Specifications:** Find detailed information on fuel system components, specifications, and troubleshooting procedures, ensuring optimal fuel efficiency and performance.
* **Emission Control:** Learn about the intricate workings of your vehicle's emission control system, enabling you to maintain compliance with environmental regulations.
* **Intake Exhaust Cooling:** Get a comprehensive understanding of your vehicle's intake, exhaust, and cooling systems, allowing you to troubleshoot and repair any issues related to these essential components.
* **Lube:** Discover the appropriate lubricants for your BMW, ensuring proper lubrication for extended engine life and performance.
* **Ignition Starting Charging:** Gain complete knowledge of your vehicle's ignition, starting, and charging systems, including troubleshooting tips for common problems.
* **Auto Transmission Clutch:** Learn the ins and outs of your automatic transmission and clutch systems, enabling you to handle repairs and adjustments confidently.
* **Manual Transmission:** If your vehicle is equipped with a manual transmission, this section provides detailed instructions on operation, maintenance, and repair.
* **Transfer Propeller Shaft:** This section covers the transfer case and propeller shaft, ensuring proper operation and addressing any potential issues.
* **Drive Shaft:** Understand the workings of your vehicle's drive shaft and learn to diagnose and repair common problems.
* **Differential:** Explore the intricacies of the differential system, ensuring optimal power distribution and handling.
* **Axle Suspension:** Discover the components and operation of your vehicle's axle and suspension systems, allowing you to perform repairs and adjustments confidently.
* **Tire & Wheel:** Find valuable information about proper tire maintenance, including tire pressure, rotation, and replacement, as well as wheel care and repair.
* **Brake Control:** Gain a thorough understanding of your vehicle's brake control system, including ABS and other electronic components, for safe and reliable braking.
* **Brake:** Learn the workings of your vehicle's braking system, including disc brakes and drum brakes, enabling you to perform adjustments, repairs, and troubleshooting.
* **Parking Brake:** Understand the operation of your parking brake and learn how to address common problems.
* **Steering Column:** Explore the workings of your vehicle's steering column and learn to diagnose and repair common issues.
* **Power Steering:** Discover the workings of your power steering system, enabling you to troubleshoot and repair problems related to steering assist.
* **Air Condition:** Learn to maintain and repair your vehicle's air conditioning system, ensuring a comfortable and cool ride.
* **Suppl Restraint System:** Understand the operation of your vehicle's supplemental restraint systems, including airbags, seat belts, and other safety features.
* **Seat Belt:** Learn to inspect, adjust, and repair your vehicle's seat belts, ensuring optimal safety for passengers.
* **Engine Immobilizer:** Find detailed information about your vehicle's engine immobilizer system, including troubleshooting and repair tips.
* **Cruise Control:** Learn how to maintain and repair your vehicle's cruise control system for effortless highway driving.
* **Wiper & Washer:** This section covers the operation and repair of your vehicle's windshield wipers and washer system, ensuring clear visibility in all conditions.
* **Door Lock:** Understand the workings of your vehicle's door lock system and learn to address any issues with locking mechanisms.
* **Meter Audio/Visual:** Find detailed information on your vehicle's instrument gauges, displays, and audio systems, enabling you to diagnose and repair any problems.
* **Horn:** Learn how to troubleshoot and repair your vehicle's horn system for proper warning and signaling.
* **Windshield/Glass Mirror:** Get advice on replacing and repairing your vehicle's windshield, side windows, and mirrors.
* **Instrument Panel:** Explore the workings of your instrument panel, covering its operation and repair, ensuring clear and functional information.
* **Seat:** Find instructions on adjusting, repairing, and replacing your vehicle's seats, ensuring passenger comfort.
* **Engine Hood/ Door:** Learn how to diagnose and repair issues with your vehicle's engine hood and doors.
* **Exterior & Interior:** This section covers various aspects of your vehicle's exterior and interior, including trim, panels, and accessories, enabling you to address cosmetic and functional problems.
* **Electrical:** Explore your vehicle's electrical system, including wiring diagrams, troubleshooting techniques, and repair procedures, allowing you to diagnose and repair electrical issues.
* **Multiplex/ Can Communication:** Understand the workings of your vehicle's multiplex and CAN communication systems for modern electronics and diagnostics.

This comprehensive manual empowers you to confidently tackle repairs and maintenance tasks, ensuring your 1981 BMW 5-series (E12) continues to perform flawlessly for years to come.

The BMW 5-Series (E12), launched in 1972, was a significant milestone for the Bavarian automaker, marking a departure from its traditional focus on luxury sedans. It introduced a new generation of sporty and agile vehicles, aimed at a more performance-oriented clientele. The first generation, known as the E12, was produced from 1972 to 1981, establishing the 5-Series as a benchmark for driving dynamics and handling in its class. The E12's streamlined design, penned by Paul Bracq, featured a low-slung silhouette, a distinctive sharknose front end, and a long wheelbase that contributed to its stable and balanced handling.

Underneath the sleek exterior lay a robust chassis and a range of powerful gasoline engines, including the legendary M535i, which boasted a 3.5-liter inline-six producing 218 horsepower. The E12's suspension, featuring independent MacPherson struts in the front and semi-trailing arms in the rear, offered precise steering and composed handling. The E12 also introduced safety features like crumple zones and a robust passenger compartment, setting a new standard for safety in the mid-size segment. While initially offered exclusively as a sedan, the E12 later spawned a wagon variant known as the Touring, further expanding its appeal to a wider range of buyers. The BMW 5-Series (E12) left a lasting legacy, establishing the 5-Series as a true icon in the automotive world and influencing subsequent generations of the model. Its combination of performance, handling, and luxury solidified its place as a driver's car, admired for its timeless design and enduring appeal.