Market Segment:
Full-size luxury sedan
Target Audience:
Owners seeking to perform their own maintenance and repairs, independent repair shops specializing in BMWs.
Competitors:
Mercedes-Benz S-Class (W126/W140), Jaguar XJ, Lexus LS 400 (from 1989).
Vehicle Key Selling Points:
V12 engine, luxurious interior, advanced technology for its era, comfortable ride, exceptional build quality.
Manual Value Proposition:
Provides essential, in-depth technical information for maintaining and repairing a complex luxury vehicle, saving on dealership service costs.
Engine:
M70 V12 engine: diagnostics, repair, overhaul, cooling system, fuel system, ignition system, lubrication, exhaust system.
Transmission:
Automatic transmission (e.g., ZF 4HP24): operation, diagnostics, repair, fluid specifications, adjustments.
Drivetrain:
Rear-wheel drive, differential, driveshafts, CV joints: inspection, repair, lubrication.
Suspension:
Front and rear suspension systems: shock absorbers, springs, control arms, bushings, steering linkage, alignment procedures.
Brakes:
Hydraulic system, ABS (Anti-lock Braking System), brake discs, pads, calipers, lines, fluid specifications, bleeding procedures.
Steering:
Power steering system, steering rack, linkages, adjustments, fluid types.
Electrical System:
12V electrical system, battery, alternator, starter, lighting, ignition, ECUs, wiring diagrams, troubleshooting guide.
Climate Control:
Automatic climate control, A/C system, heating system, blower motor, refrigerant, diagnostic procedures.
Bodywork:
Exterior panels, doors, hood, trunk, glass, interior trim, body repair, corrosion prevention.
Chassis:
Frame construction, structural components, rust prevention, body mounting.
Maintenance:
Scheduled maintenance, oil changes, filter replacements, fluid checks and top-offs, tune-ups.
Diagnostics:
Troubleshooting common problems, diagnostic trouble codes (DTCs), systematic fault finding.
Repair:
Step-by-step repair instructions for all major vehicle systems, component replacement, adjustments.
Overhaul:
Detailed procedures for engine and transmission overhauls.
Wiring Diagrams:
Comprehensive electrical wiring schematics for all vehicle systems.
Depth:
Comprehensive. Covers basic maintenance to full engine/transmission rebuilds and advanced electrical diagnostics.
Engine Configuration:
V12 (12-cylinder, 60-degree bank angle)
Displacement:
5.0 liters (4988 cc)
Bore X Stroke:
84.0 mm x 75.0 mm
Horsepower:
295-300 hp (217-221 kW) @ 5200 rpm (depending on market regulations)
Torque:
332 lb-ft (450 Nm) @ 4100 rpm
Fuel Delivery:
Bosch Motronic M1.2 Electronic Fuel Injection (EFI) with two injectors per cylinder.
Fuel Type:
Premium Unleaded Gasoline (91+ octane recommended)
Engine Control Unit:
Dual Engine Control Units (ECUs), one for each bank of cylinders.
Gear Ratios:
Typical: 1st: 2.48, 2nd: 1.48, 3rd: 1.00, 4th: 0.727, Reverse: 2.08
Fluid Type:
BMW ATF LT 71141 or equivalent (e.g., Pentosin ATF1, Mobil ATF 220/3309)
Fluid Capacity:
Approximately 9.5 liters (dry fill), check manual for service fill amount.
Crash Test Results:
No comprehensive official crash test data from agencies like NHTSA or IIHS is readily available for this specific model and era, but BMW's passive safety systems were generally advanced for the time.
ABS:
Standard Anti-lock Braking System (ABS)
Traction Control:
Optional ASC (Automatic Stability Control) on later models.
Airbags:
Driver's side airbag standard from 1990 onwards; passenger airbag optional.
Seatbelts:
3-point inertia-reel seatbelts with pretensioners for front occupants.
Body Structure:
Reinforced passenger cell, crumple zones, side impact protection beams.
Audio System:
BMW Bavaria C Business/Professional radio, optional CD player, cassette player.
Display:
Digital check control display for vehicle status and warnings.
Cruise Control:
Standard electronic cruise control.
Parking Assistance:
Optional rear parking sensors (early generation).
Telematics:
Optional BMW On-Board Computer, cellular phone integration (early systems).
Seats:
Power-adjustable front seats with memory, optional heated seats, rear climate control, rear power seats (on some models).
Oil Change Interval:
Typically every 7,500-10,000 miles (12,000-15,000 km) or 12 months, depending on driving conditions. Check manual for specific interval based on oil condition monitoring (if equipped).
Air Filter Replacement:
Every 15,000-30,000 miles (24,000-48,000 km) or as needed.
Spark Plug Replacement:
Iridium spark plugs often have intervals of 60,000-100,000 miles (96,000-160,000 km). Platinum or copper plugs will have shorter intervals. Refer to manual for specific plug type and interval.
Transmission Fluid Change:
Recommended every 50,000-60,000 miles (80,000-96,000 km), or sooner under severe conditions. Note: Some sources suggest sealed transmissions, but fluid changes are still advisable.
Engine Oil:
SAE 5W-30 or 5W-40 synthetic or semi-synthetic oil meeting BMW LL-01 or API SN/CF specifications (check manual for precise specification).
Coolant:
BMW Blue Coolant (G48 ethylene glycol based) or compatible coolant, mixed 50/50 with distilled water.
Brake Fluid:
DOT 4 low-viscosity (LF) brake fluid
Common Problems:
V12 complexity (expensive to repair), fuel injector issues (common on M70), cooling system leaks (plastic components), ABS sensor failures, electrical gremlins, headliner sag, strut mount wear, throttle body issues (two per bank).
M70 Specific Issues:
The dual ignition and dual injection systems, while advanced, require specialized knowledge and can be costly to maintain. Oil leaks from V-banks are also common.
Bmw Philosophy:
BMW's reputation for 'The Ultimate Driving Machine,' blending performance, luxury, and engineering excellence.
E32 Introduction:
The E32 generation (1986-1994) replaced the E23 7 Series, introducing a more aerodynamic and sophisticated design, and significantly updated technology. The 750iL, introduced in 1987, was the flagship model featuring the new V12 engine.
750Il Significance:
The 750iL was BMW's first production V12 engine, directly challenging Mercedes-Benz's long-standing dominance in the V12 luxury sedan segment. It represented the pinnacle of automotive engineering from BMW at the time.
Production Period:
1988-1994
Manufacturing Location:
Dingolfing, Germany
