Positioning:
The 1991 BMW 750iL (E32) represented the pinnacle of BMW's luxury sedan offerings, competing with other flagship models from Mercedes-Benz (S-Class) and other luxury marques.
Competitors:
Mercedes-Benz W140 S-Class, Lexus LS 400, Jaguar XJ series.
Vehicle Highlights:
V12 engine, long wheelbase (iL designation), sophisticated luxury amenities, advanced (for its time) technology, refined ride quality.
Value:
Provides essential information for owners and technicians to maintain and repair this complex luxury vehicle, preserving its performance and longevity.
Engine:
Detailed troubleshooting, repair, and overhaul for M70 V12 engine, including dual ignition and fuel injection systems.
Transmission:
Repair and maintenance of the 4-speed automatic transmission (e.g., ZF 4HP24).
Drivetrain:
Rear-wheel drive system, driveshaft, differential, axle shafts.
Suspension:
Front and rear suspension components, including struts, control arms, bushings, and potentially self-leveling rear suspension (if applicable to specific 1991 models).
Brakes:
Hydraulic brake system, ABS (Anti-lock Braking System) diagnostics and repair, front/rear brake assembly, parking brake.
Steering:
Power steering system, steering gear, steering column, wheel alignment specifications.
Electrical:
Complete wiring diagrams, fuse box locations, battery, alternator, starter, lighting systems, power accessories, instrument cluster, onboard diagnostics (OBD I).
Body:
Body shell repair, doors, windows, locks, body hardware, interior trim, exterior trim, paint specifications, rust prevention.
HVAC:
Climate control system, A/C compressor, refrigerant, heater core, blower motor, controls.
Fuel System:
Fuel tank, fuel pump, fuel lines, fuel injectors, fuel pressure regulator, emission control systems.
Cooling System:
Radiator, coolant, water pump, thermostat, cooling fan, hoses.
Exhaust System:
Exhaust manifolds, catalytic converters, mufflers, pipes.
Maintenance:
Routine maintenance checks, oil changes, filter replacements, spark plug replacement, fluid checks and top-offs.
Troubleshooting:
Diagnostic procedures for common and uncommon issues, fault codes interpretation (OBD I).
Repair:
Step-by-step repair instructions for all major vehicle systems.
Overhaul:
Complete engine and transmission overhaul procedures, including component specifications and tolerances.
Diagnostics:
Detailed diagnostic flowcharts and procedures for electrical and mechanical systems.
Installation:
Procedures for installing replacement parts and accessories.
Depth:
Comprehensive: Covers everything from basic maintenance to complete engine and transmission rebuilds, electrical diagnostics, and bodywork.
Engine Configuration:
V12, 60-degree bank angle
Displacement:
4.988 liters (304.4 cu in)
Horsepower SAE Net:
296 hp @ 5200 rpm
Torque SAE Net:
332 lb-ft @ 3900 rpm
Fuel Delivery:
Electronic multi-point fuel injection (Bosch Motronic DME)
Fuel Type:
Premium Unleaded Gasoline (91 octane or higher)
Ignition Type:
Dual ignition system (two spark plugs per cylinder)
Bore X Stroke:
84.0 mm x 90.0 mm
Cooling Capacity:
Approx. 14.0 liters (14.8 quarts)
Audio System:
Premium Hi-Fi audio system, often with Nakamichi branding, cassette player.
Navigation:
Optional early GPS navigation system available on some models.
Traction Control:
Automatic Stability Control (ASC) available on some models.
Phone:
Optional integrated car phone system.
Onboard Diagnostics:
OBD I (On-Board Diagnostics I) system with proprietary BMW diagnostic connectors and procedures.
Oil Change:
Refer to manual for specific interval, typically every 7,500 - 10,000 miles or annually, depending on driving conditions. Use synthetic oil.
Spark Plugs:
Inspect at 30,000 miles, replace as needed. Dual plugs per cylinder require specific Bosch plugs.
Coolant Flush:
Every 2 years or 30,000 miles.
Engine Oil:
SAE 5W-30 or 10W-30 Synthetic (refer to manual for exact BMW approval).
Coolant:
BMW Blue Antifreeze/Coolant (or equivalent ethylene glycol-based coolant with corrosion inhibitors).
Brake Fluid:
DOT 4 Low Viscosity (LV) brake fluid.
Power Steering Fluid:
BMW Power Steering Fluid (Pentosin CHF 11 S or compatible).
Engine M70:
Coil pack failure (due to dual ignition), idle control issues, sensor failures (e.g., MAF), oil leaks, specific harness issues. The manual addresses diagnostics for these.
E32 Common:
ABS/ASC errors, climate control module faults, headliner sagging, door seal degradation, central locking issues, wear on suspension bushings.
Part Notes:
Specialized V12 parts may be scarce; manual helps identify correct part numbers for sourcing.