Engine Mechanical:
Detailed diagnostics, overhaul procedures, timing, valve adjustments, cooling system, lubrication
Fuel System:
Fuel injection systems (Bosch Motronic), fuel pumps, injectors, pressure regulators, emissions control
Ignition System:
Ignition timing, coil, distributor, spark plugs, electronic control modules
Transmission Manual:
Clutch, gearbox overhaul, shift linkages, fluid specifications
Transmission Automatic:
Automatic transmission servicing, adjustments, hydraulic systems, fluid types
Drivetrain Rear Axle:
Differential, driveshafts, U-joints, axle seals, lubrication
Suspension Front:
Struts, control arms, ball joints, bushings, alignment specifications
Suspension Rear:
Trailing arms, shock absorbers, springs, bushings, alignment specifications
Steering:
Steering rack, power steering pump, hoses, tie rods, steering column
Brakes Front:
Disc brake calipers, rotors, pads, brake lines, ABS system components
Brakes Rear:
Disc brake calipers, rotors, pads, parking brake mechanism, ABS system components
Electrical System Charging:
Alternator, voltage regulator, battery testing and replacement
Electrical System Starting:
Starter motor, ignition switch, wiring diagrams
Lighting System:
Headlights, taillights, interior lights, fuse box diagrams
Comfort Controls:
HVAC system, heater core, blower motor, A/C system servicing
Body And Chassis:
Body panel removal and installation, door mechanisms, window regulators, seals
Body And Chassis Rust Proofing:
Corrosion protection procedures and recommendations
Routine Maintenance:
Oil changes, filter replacements, spark plug service, fluid checks and top-offs
Troubleshooting Diagnostics:
Systematic diagnostic flowcharts for common and complex issues
Component Overhaul:
Engine rebuild, transmission rebuild, differential overhaul
Special Tools:
Identification and usage of necessary special tools for specific repairs
Wiring Diagrams:
Detailed electrical schematics for all vehicle systems
Depth:
Comprehensive, covering everything from basic preventative maintenance to complex engine and transmission rebuilds. This is a factory-level technical guide.
Oil Change Interval:
Typically every 7,500-10,000 miles or 12 months, depending on driving conditions (refer to manual for specifics)
Spark Plug Replacement:
Varies by plug type (e.g., copper vs. platinum), often 30,000-60,000 miles
Timing Belt Replacement:
M40 engines have timing belts; M20/S14 engines use chains. Belts typically 40,000-60,000 miles or 4-5 years.
Engine Oil:
Refer to manual for specific viscosity grades (e.g., 10W-40, 15W-50) and API service classifications
Coolant:
BMW Blue or compatible Ethylene Glycol based coolant, typically 50/50 mix with distilled water
Transmission Fluid Manual:
API GL-4 or GL-5 gear oil (specific weight varies, e.g., 75W-90)
Transmission Fluid Automatic:
ATF Dexron II or equivalent
Differential Fluid:
API GL-5 gear oil (e.g., 75W-90). LSD requires specific friction modifier additive.
Rear Subframe Mounts:
Cracking or failure of rear subframe mounting points
Heater Core Leaks:
Common failure leading to coolant smell and fogging windows
Fuel Injector Seals:
Degradation of O-rings causing fuel leaks or rough running
Window Regulator Failure:
Plastic components breaking, preventing window operation
Oil Pan Gasket Leaks:
Common on higher mileage M20 engines
