Historical Context:
The E21 was BMW's first dedicated 3 Series, establishing the benchmark for compact executive sedans with a focus on sporty driving dynamics, build quality, and refined engineering. This manual provides access to the factory-level knowledge required to maintain these classic vehicles.
Comparative Advantage:
Competed against vehicles like the Mercedes-Benz W123, Audi 80, and Alfa Romeo Alfetta, offering a more driver-focused experience. This manual ensures owners and technicians can maintain that original driving feel.
Value Proposition:
Provides access to the same detailed, manufacturer-approved repair and diagnostic information used by official BMW dealerships, enabling professional-level servicing and troubleshooting for the E21 generation.
Accessibility:
Digital format (PDF) offers immediate download access, cross-platform compatibility, and easy navigation through its structured content.
Engines Covered:
M10 4-cylinder (e.g., M10B18, M10B20), M20 6-cylinder (e.g., M20B20, M20B23)
Body Styles Covered:
2-door Sedan, Convertible (Baur)
Estimated Page Count:
Thousands of pages (typical for comprehensive factory workshop manuals)
Type:
Workshop Service and Repair Manual
Language:
English (assumed based on product description)
Compatibility:
Windows & MAC compatible
Powertrain:
Engine mechanical (M10, M20 series), Fuel injection (Bosch K-Jetronic, L-Jetronic), Ignition system, Cooling system, Exhaust system
Drivetrain:
Manual transmission, Automatic transmission, Clutch, Drive shafts, Differential, Axles
Chassis:
Front suspension (MacPherson struts), Rear suspension (semi-trailing arms), Steering system (recirculating ball, power steering option), Brakes (front disc, rear drum/disc), Wheels and tires
Electrical:
Wiring diagrams, Battery, Alternator, Starter motor, Lighting system, Instrumentation, Fuses and relays, Ignition switches
Body:
Body panels, Doors, Hood, Trunk lid, Glass, Interior trim, Seats, Bumpers
Maintenance:
Oil changes, Filter replacements, Spark plug service, Brake fluid flush, Coolant flush, Belts and hoses inspection/replacement, Tune-ups
Repair:
Engine rebuilds, Cylinder head service, Piston/ring replacement, Crankshaft bearing service, Transmission overhaul, Clutch replacement, Brake caliper/master cylinder rebuild, Suspension component replacement, Steering rack/box repair, Electrical component diagnosis and replacement
Diagnostics:
Troubleshooting guides for common issues, Engine performance diagnostics, Electrical system fault finding, Fuel system testing
Technical Data:
Torque specifications, Fluid capacities, Diagnostic trouble codes (DTCs) if applicable, Measurement specifications
Depth:
Comprehensive - covering all aspects from routine maintenance to full engine and transmission rebuilds, including detailed diagnostic procedures and electrical schematics.
Engine Family:
BMW M10 (4-cylinder)
Displacement Variants M10:
1.8L (M10B18), 2.0L (M10B20)
Secondary Engine Family:
BMW M20 (6-cylinder)
Displacement Variants M20
Displacement Variants M20:
2.0L (M20B20), 2.3L (M20B23)
Typical Horsepower Range:
75 hp (1.8L carb) to 143 hp (2.3L fuel injected)
Typical Torque Range:
130 Nm (1.8L) to 205 Nm (2.3L)
Fuel Delivery Carbureted:
Single/Dual Solex Zenith carburetors (e.g., 40 DIDTA)
Fuel Delivery Injected:
Bosch K-Jetronic (CIS), Bosch L-Jetronic (less common)
Ignition System:
Mechanical distributor with breaker points or electronic ignition (later models)
Fuel Management:
Mechanical fuel injection control unit (for K-Jetronic)
Transmission Type Standard:
4-speed Manual
Transmission Type Optional:
3-speed Automatic (ZF 3 HP 12 or 14)
Clutch Type:
Single dry plate, hydraulically operated
Final Drive Ratio:
Varies by model and transmission (e.g., 3.64:1, 3.91:1)
Wheelbase:
Approximately 2570 mm (101.2 in)
Length:
Approximately 4370 mm (172.0 in)
Width:
Approximately 1610 mm (63.4 in)
Height:
Approximately 1380 mm (54.3 in)
Curb Weight:
Approximately 1150 - 1250 kg (2535 - 2755 lbs) depending on engine and equipment
Gross Vehicle Weight Rating:
Typically around 1600 kg
Trunk Volume:
Approx. 470 liters (16.6 cubic feet)
Crash Test Performance:
Limited official crash test data available for the era, but known for robust construction typical of German cars.
Braking System:
Front: Ventilated discs; Rear: Drums (standard), Discs (optional on some models)
Parking Brake:
Mechanical, acting on rear wheels
Seatbelts:
Standard 3-point front seatbelts, optional rear lap belts
Headrests:
Standard front headrests
Steering Column:
Collapsible steering column
Audio System:
Optional factory radio with analog tuning and cassette player. Aftermarket upgrades common.
ABS:
Not typically available on early E21 models. Became optional or standard on later variants of 3 Series.
Power Steering:
Optional on most models, enhancing maneuverability.
OBD:
No On-Board Diagnostics (OBD) port in the modern sense. Diagnostics rely on mechanical checks, voltage readings, and visual inspection as detailed in the manual.
Oil Change Interval:
Typically 5,000-7,500 miles or 6-12 months, depending on driving conditions. Consult manual for specific recommendations.
Major Service Intervals:
Spark plug replacement, air filter, fuel filter, timing belt (if applicable - M20 uses a chain, M10 uses a belt), brake service at higher mileage intervals (e.g., 30,000 miles).
Engine Oil Type:
API SF/SG or ACEA A2/A3, viscosity typically 10W-40 or 20W-50 depending on climate. Specific BMW approval recommended (e.g., BMW Longlife-98 for later period).
Coolant Type:
Ethylene glycol based coolant, typically a 50/50 mix with distilled water. BMW blue coolant or equivalent. Do not mix with green coolant.
Brake Fluid Type:
DOT 3 or DOT 4 glycol-based brake fluid.
Transmission Fluid Manual:
GL-4 Gear Oil, SAE 75W-90 or 80W-90. Consult manual for specific BMW recommendation.
Transmission Fluid Automatic:
Dexron III/Mercon equivalent ATF (Automatic Transmission Fluid). BMW ATF DIII.
Rust Prone Areas:
Wheel arches, rocker panels, strut towers, battery tray, rear valence.
Engine M10:
Oil leaks from rear main seal, valve cover gasket. Overheating if cooling system neglected. Carburetor issues.
Engine M20:
Head gasket failures, timing belt (if belt-driven variant used, although typically chain driven) failure leading to catastrophic engine damage, oil leaks.
Suspension:
Wear in control arm bushings, ball joints, and rear trailing arm bushings. Shock absorber degradation.
Electrical:
Degradation of wiring insulation, corrosion in connectors, failure of alternator, starter, and voltage regulator.
Fuel System:
Clogged fuel injectors or fuel distributor (K-Jetronic), worn fuel pump, aged rubber fuel lines.
Bmw Philosophy:
BMW's commitment to 'The Ultimate Driving Machine' began to solidify with models like the E21, emphasizing performance, handling, and build quality.
E21 Introduction:
Introduced in 1975 as the successor to the BMW 02 Series, setting the foundation for the iconic 3 Series lineage.
Styling:
Designed by Paul Bracq, featuring BMW's signature kidney grille and a clean, wedge-shaped profile. Notable for its driver-oriented dashboard.
Facelifts:
Minor updates throughout its production, including revised trim, improved ergonomics, and engine enhancements.
Production Period:
1975-1983
Production Volume:
Over 750,000 units produced globally.
Manufacturing Locations:
Primarily Dingolfing, Germany, with some assembly in other locations.
Automotive Press:
Consistently praised by automotive press for its handling, build quality, and sporty character. Considered a benchmark for its class during its production run.
Owner Satisfaction:
High owner satisfaction for its driving dynamics and longevity, though maintenance can be demanding if neglected.
Manual Quality:
Factory original workshop manuals are the highest standard of accuracy and completeness for vehicle repair.
