Market Segment:
Compact executive sports sedan
Target Audience:
Enthusiasts, DIY mechanics, owners seeking to maintain and repair their classic BMW
Key Competitors:
Mercedes-Benz W123 (240D, 230E), Audi 80/Fox, Alfa Romeo Alfetta, Ford Sierra
Vehicle Philosophy:
Driver-focused, balanced handling, quality engineering
Manual Value Proposition:
Provides detailed, expert guidance for maintaining and repairing the iconic E21 3 Series
Engine:
M10 engine family, including M10B20 (2.0L inline-4)
Fuel System:
Bosch L-Jetronic fuel injection system, fuel pump, injectors, lines, tank
Ignition System:
Electronic ignition, distributor, coil, spark plugs, wiring
Transmission:
4-speed and 5-speed manual transmissions, clutch system, driveshafts
Suspension:
Front MacPherson struts, rear semi-trailing arms, springs, dampers, bushings
Brakes:
Front disc brakes, rear drum brakes, hydraulic system, parking brake
Steering:
Recirculating ball steering system, steering column, linkages
Electrical System:
12V system, alternator, starter motor, battery, lighting, fuses, relays, wiring diagrams
Cooling System:
Radiator, fan, thermostat, water pump, coolant passages
Exhaust System:
Exhaust manifold, catalytic converter (later models), muffler, pipes
Body And Chassis:
Unibody construction, body panels, doors, hood, trunk, interior trim
HVAC:
Heater core, ventilation system, controls
Maintenance:
Oil changes, filter replacements, spark plug checks, fluid checks and changes
Troubleshooting:
Diagnostic procedures for engine performance, electrical faults, and mechanical issues
Repair:
Step-by-step instructions for component replacement and repair across all systems
Overhaul:
Engine and transmission overhaul procedures
Adjustment:
Valve clearance adjustment, ignition timing adjustment, carburetor/fuel injection tuning
Specifications:
Torque specifications for critical fasteners, clearances, fluid capacities, and wear limits
Depth:
Comprehensive, covering routine maintenance to complete engine and transmission rebuilds
Engine Type:
Inline 4-cylinder, SOHC
Displacement:
1990 cc (2.0 Liters)
Horsepower:
115 PS (113 hp) at 5800 rpm (approximate, varies by market/emission standards)
Torque:
165 Nm (122 lb-ft) at 3500 rpm (approximate)
Fuel Delivery:
Bosch L-Jetronic Electronic Fuel Injection
Fuel Type:
Unleaded gasoline (minimum 91 RON recommended)
Engine Control Unit:
Bosch Motronic (integrated ignition and fuel management in later versions)
Type:
5-speed Manual, 3-speed ZF Automatic (optional)
Clutch Type:
Single dry plate diaphragm spring clutch
Gear Ratios:
Specific gear ratios provided in manual for each transmission type
Manual Transmission Fluid:
API GL-4, SAE 75W-90 or 80W-90 (check manual for exact BMW specification)
Automatic Transmission Fluid:
Dexron II or equivalent (for automatic models)
Crash Test Ratings:
N/A (No standardized ratings available for this era)
Brakes:
Front ventilated disc brakes, rear drum brakes
Steering:
Recirculating ball steering (non-power assisted standard, power assisted optional on later models)
Seatbelts:
Three-point front seatbelts, two-point rear seatbelts (three-point rear optional/market dependent)
Body Structure:
Reinforced passenger cell, crumple zones
Oil Change Interval:
Every 5,000-7,500 miles (8,000-12,000 km) or annually (refer to manual for specific recommendation)
Filter Replacement Interval:
Oil filter with every oil change; air filter and fuel filter every 15,000-30,000 miles (24,000-48,000 km)
Timing Belt Chain:
M10 engines use a timing chain, which is generally maintenance-free but requires inspection for wear/stretch.
Engine Oil Type:
API SG/SH, SAE 15W-40 or 10W-40 (check manual for specific BMW recommendation, synthetic blends are beneficial)
Coolant Type:
Ethylene glycol based antifreeze, mixed 50/50 with distilled water
Power Steering Fluid:
ATF Dexron II (if equipped with power steering)
Engine Mounts:
Wear and degradation leading to vibration and noise.
Rust:
Common on wheel arches, sills, door bottoms, and trunk floor.
Fuel Lines:
Degradation of rubber fuel lines and fittings over time.
Electrical Connections:
Corrosion and loose connections in wiring harnesses and grounds.
Cooling System:
Leaking hoses, cracked radiator end tanks, failing water pump.
Bmw Heritage:
BMW's commitment to sporting sedans and driver engagement
E21 Introduction:
Introduced in 1975 as the successor to the BMW 02 Series, setting the foundation for the 3 Series legacy.
E21 Design:
Iconic 'Hofmeister kink', driver-oriented dashboard, distinctive kidney grille.
Manufacturing Locations:
Mainly Munich, Germany; also Dingolfing, Germany and Rosslyn, South Africa.
Total Production E21:
Approx. 1.36 million units
