Engine Mechanical:
All engine variants (M10, M20, M30, M40, M42, S14), including disassembly, reassembly, overhaul, diagnostics, and specifications.
Fuel System:
Fuel injection (Bosch L-Jetronic, Motronic), carburetors (early models), fuel pumps, lines, filters, evaporative emissions control.
Ignition System:
Distributor ignition, electronic ignition, coil, spark plugs, ignition timing, diagnostics.
Cooling System:
Radiator, fan, water pump, thermostat, hoses, coolant specifications, flushing, bleeding procedures.
Exhaust System:
Exhaust manifold, catalytic converter (where applicable), mufflers, pipes, heat shields, oxygen sensors.
Transmission Manual:
Manual gearboxes (Getrag 260, 240), clutch system, driveshafts, differentials, fluid specifications, repair, and overhaul.
Transmission Automatic:
Automatic transmissions (ZF 4HP22 EH), hydraulic control, torque converter, fluid specifications, repair, and overhaul.
Suspension Front:
MacPherson struts, control arms, sway bars, bushings, wheel bearings, steering linkage.
Suspension Rear:
Semi-trailing arms, shock absorbers, springs, bushings, wheel bearings, trailing arm bearings.
Brakes Front:
Ventilated disc brakes, calipers, pads, rotors, fluid specifications, bleeding procedures.
Brakes Rear:
Solid disc brakes (most models), calipers, pads, rotors, handbrake mechanism, fluid specifications.
Steering System:
Recirculating ball steering, power steering system (pump, rack, hoses), steering column, U-joints, alignment specifications.
Electrical System Charging:
Alternator, voltage regulator, battery, wiring diagrams for charging circuit.
Electrical System Starting:
Starter motor, ignition switch, starter solenoid, wiring diagrams for starting circuit.
Electrical System Lighting:
Headlights, taillights, turn signals, interior lighting, bulb types, wiring diagrams.
Electrical System Instruments:
Dashboard instruments (speedometer, tachometer, fuel gauge, temp gauge), warning lights, wiring.
Electrical System Accessories:
Wipers, washers, power windows, power locks, sunroof, horn, radio, HVAC blower motor, fuse box.
Body Exterior:
Body panels, doors, hood, trunk, bumpers, glass, trim, corrosion protection.
Body Interior:
Seats, dashboard, door panels, carpeting, headliner, climate controls, interior trim.
HVAC System:
Heating, ventilation, and air conditioning (HVAC) system, blower motor, heater core, evaporator, refrigerant, control modules.
Routine Maintenance:
Oil changes, filter replacements, spark plug replacement, fluid checks and changes, belt inspections and replacement.
Troubleshooting:
Diagnostic flowcharts, symptom-based troubleshooting for all major systems, fault code interpretation (where applicable).
Engine Repair:
Cylinder head removal/installation, piston/ring replacement, crankshaft main bearing replacement, camshaft timing.
Transmission Repair:
Clutch replacement, transmission disassembly/reassembly, torque converter replacement, shift linkage adjustment.
Brake System Repair:
Brake pad/rotor replacement, caliper rebuilding, brake line replacement, brake bleeding, ABS diagnostics (where applicable).
Suspension Repair:
Control arm bushing replacement, ball joint replacement, strut/shock absorber replacement, wheel bearing replacement.
Electrical Diagnostics:
Wiring harness repair, component testing, fuse and relay troubleshooting, diagnosing electrical faults.
Bodywork Repair:
Panel alignment, rust repair, welding procedures, glass replacement, door mechanism repair.
HVAC Repair:
Evacuating and recharging A/C system, heater core replacement, blower motor replacement, control panel repair.
Diagnostic Capabilities:
In-depth diagnostic procedures, including common failure points and advanced troubleshooting techniques.
Rebuild Procedures:
Comprehensive instructions for overhauling major components like engines, transmissions, and differentials.
Specifications:
Torque specifications for all fasteners, engine timing marks, valve clearances, electrical resistance values, diagnostic parameters.
Wiring Diagrams:
Detailed, system-specific wiring diagrams for all electrical components and circuits.
Exploded Views:
Numerous exploded-view diagrams illustrating component assembly and disassembly.
Oil Change Interval:
Typically every 5,000-7,500 miles or 6-12 months, depending on driving conditions. Consult manual for specific engine recommendations.
Timing Belt Interval:
For M10 and M20 engines: Replace every 40,000-60,000 miles or 4-5 years. For M42/S14: Timing chain, typically requires inspection, not periodic replacement.
Brake Fluid Flush:
Every 2 years or 30,000 miles is recommended.
Coolant Flush:
Every 2-3 years or 30,000-50,000 miles.
Engine Oil:
API SG or higher, SAE 10W-40 or 15W-50 depending on climate. BMW recommends Castrol. Specific viscosity varies by engine. (e.g., 5W-30 for M42).
Transmission Fluid Manual:
BMW ATF Dexron II or equivalent for 5-speed gearboxes. Check manual for specific GL-4 or GL-5 gear oil for older units.
Transmission Fluid Automatic:
BMW ATF Dexron II or Dexron III. Capacity typically 5-7 liters.
Coolant:
Ethylene glycol-based coolant with corrosion inhibitors, typically a 50/50 mix with distilled water. BMW blue coolant or equivalent.
Brake Fluid:
DOT 3 or DOT 4 brake fluid. Always use fresh fluid.
Cooling System Weaknesses:
Plastic coolant expansion tanks can become brittle and crack; water pumps can leak; thermostat housing seals can fail.
Rear Axle Bushings:
Trapezoidal bushings (RTABs) and trailing arm bushings are common wear items that can affect handling and cause clunking noises.
Rust:
Common rust areas include fender wells, rocker panels, battery tray, and rear window surround. Thorough inspection is crucial.
Window Seals:
Door and window seals can degrade, leading to water leaks into the cabin, especially with convertibles.
Idle Control Valve:
Can become clogged on some fuel-injected models, leading to rough idle or stalling.
Fuel Injector Seals:
O-rings can harden and leak on fuel-injected models, causing vacuum leaks and performance issues.