Target Audience:
BMW E21 owners, independent repair shops, automotive enthusiasts
Value Proposition:
Provides official factory data, enabling accurate and cost-effective repairs, bypassing dealership dependency.
Uniqueness:
Official factory content ensures accuracy and completeness unmatched by generic aftermarket guides.
Access Method:
Instant digital download for immediate access and ability to print specific sections.
Powertrain:
Engine (M10, M20), Ignition System, Cooling System, Fuel System, Transmission (4-speed manual, 5-speed manual, automatic), Drivetrain, Differential, Driveshaft
Chassis Suspension:
Front Suspension (MacPherson struts), Rear Suspension (Semi-trailing arms), Steering System (Recirculating ball), Brake System (Front discs, Rear drums/discs), Wheels & Tires, Body, Chassis
Electrical Electronics:
Body Electrical Systems, Electronic Control Modules (ECU - where applicable), Instrument Cluster, Lighting Systems (Headlamps, Taillamps, Interior), Power Systems (Alternator, Battery, Starter), Message Systems, Chime/Buzzer, Heated Systems (Rear defroster), Horn
Comfort Convenience:
Heating System, Ventilation, Air Conditioning (HVAC), Audio Systems
Maintenance Lubrication:
Detailed lubrication schedules, fluid specifications, maintenance procedures
Diagnostic Troubleshooting:
Troubleshooting charts, symptom-based diagnostics, electrical fault finding
Repair Replacement:
Step-by-step repair instructions for all major components and systems
Maintenance Tasks:
Scheduled maintenance, fluid changes, filter replacements, tune-ups
Electrical Wiring:
Detailed wiring diagrams for all circuits
Depth:
Intermediate to Advanced: Covers routine maintenance, component removal/installation, and in-depth diagnostic procedures.
Engine Families:
M10 (4-cylinder), M20 (6-cylinder)
Common Engine Variants:
315: M10B18 (1.8L), 316: M10B18 (1.8L), 318: M10B18 (1.8L), 320i: M20B20 (2.0L), 323i: M20B23 (2.3L)
Power Output Range:
Approximately 90 HP to 145 HP (depending on engine and market)
Torque Output Range:
Approximately 130 Nm to 190 Nm (depending on engine)
Fuel Delivery:
Carbureted (Zenith, Solex) for base models, Bosch L-Jetronic Fuel Injection for 'i' models
Fuel Type:
Unleaded gasoline (Premium unleaded recommended)
Spark Plug Type:
Bosch W8AC or equivalent (refer to manual for specific engine)
Engine Oil Capacity:
Approximately 4.25 - 5.0 Liters (4.5 - 5.3 Quarts) (refer to manual for specific engine)
Engine Oil Viscosity:
SAE 20W-50 or 10W-40 (depending on climate and application, consult manual)
Gearbox:
4-speed manual transmission
Gearbox:
5-speed manual transmission, 3-speed automatic transmission (ZF)
Clutch Type:
Single dry plate, hydraulically actuated
Manual Transmission Fluid:
GL-4 Gear Oil (e.g., Castrol EPX 80W-90 or equivalent)
Automatic Transmission Fluid:
Dexron III or equivalent (consult manual for exact specification)
Body Styles:
2-door sedan, 4-door sedan
Wheelbase:
Approx. 2565 mm (100.98 inches)
Curb Weight Range:
Approx. 1100 - 1250 kg (2425 - 2755 lbs) (depending on model and equipment)
Gross Vehicle Weight Rating:
Varies by model, consult manual
Crash Test Data:
Limited official crash test data available for this era, but known for robust construction.
Braking System:
Front ventilated disc brakes, rear drum brakes (later models and higher trims may have rear discs)
Parking Brake:
Mechanical handbrake operating on rear wheels
Seatbelts:
Standard 3-point front seatbelts, lap belts for rear passengers
Steering Column:
Collapsible steering column for improved impact protection
Audio System:
Optional factory radio, typically AM/FM with cassette player. Aftermarket options common.
ABS:
Anti-lock Braking System (ABS) was not standard and was a rare option, typically found on later E21 models or specific performance variants.
Cruise Control:
Optional on some higher-trim models.
Connectivity Features:
None (Era appropriate technology, no modern connectivity features)
Oil Change Interval:
Typically every 5,000 - 10,000 km (3,000 - 6,000 miles) or annually (consult manual for exact recommendation)
Filter Replacement:
Oil filter with every oil change, air filter and fuel filter periodically (e.g., 20,000 - 40,000 km)
Timing Belt Chain:
M10 engines use a timing chain (generally long-lasting), M20 engines use a timing belt (recommend replacement every 60,000 - 80,000 km or 4-5 years).
Coolant Type:
Ethylene glycol based coolant, typically a 50/50 mix with distilled water
Brake Fluid Type:
DOT 3 or DOT 4 brake fluid (consult manual for exact specification)
Common Problems:
Rust (especially wheel arches, rocker panels, strut towers), fuel system leaks (especially with age), vacuum leaks, cooling system component deterioration (hoses, radiator), electrical gremlins (corroded connections), worn suspension bushings.
Carburetor Tuning:
Carburetors may require periodic adjustment and rebuild due to wear and gumming.
Bmw Legacy:
BMW's reputation for sporting sedans and driver engagement established with models like the 02 Series.
Predecessor:
BMW 02 Series (e.g., 1502, 1802, 2002)
Successor:
BMW E30 3 Series
Production Years:
1975 - 1983
Manufacturing Locations:
Munich, Germany; Rosslyn, South Africa
Key Design Features:
Designed by Paul Bracq, distinctive shark-nose front end, MacPherson strut front suspension for improved handling.
Automotive Press:
The E21 was praised for its driving dynamics and build quality, continuing BMW's reputation for sporty sedans.
Consumer Reports:
Often cited for reliability and performance in contemporary reviews, though age-related wear is a factor.
Engineering Standards:
Built to German engineering standards of the era.
