Positioning:
The BMW 8 Series (E31) was BMW's flagship grand tourer, representing the pinnacle of BMW engineering and luxury for its era. It competed with high-end coupes and GT cars from marques like Mercedes-Benz (SL-Class), Porsche (928), and Aston Martin.
Key Competitors:
Mercedes-Benz R129 SL, Porsche 928, Jaguar XJS, Aston Martin DB7 (later in production)
Design Philosophy:
Aerodynamic styling, advanced technology (for its time), powerful V12 engine, luxurious interior, and superior driving dynamics.
Manual Value Proposition:
This manual provides the essential technical knowledge for maintaining and repairing a complex, high-performance luxury vehicle. It is crucial for preserving the integrity and performance of the iconic 850i.
Primary Coverage:
Workshop Service and Repair
Target Audience:
Mechanical Technicians, DIY Enthusiasts
Estimated Pages:
Estimates vary by specific BMW editions, but typically comprehensive workshop manuals for this era are between 1000-2000+ pages.
Type:
Workshop Service Manual
Language:
English (Primary), German (Original)
Format:
PDF (Digital Download)
Powertrain:
Engine (M70 V12), Fuel System, Exhaust System, Engine Management (DME), Transmission (Automatic - 4HP24 / 5HP30 variations), Driveline, Differential
Chassis:
Suspension (Front and Rear, including self-leveling rear suspension), Steering System, Brakes (ABS, Disc Brakes), Wheels and Tires
Electrical:
Complete Electrical System, Wiring Diagrams, Engine Control Unit (ECU), Lighting, Instruments and Gauges, Body Control Modules, Power Accessories, Ignition System, Battery and Charging System
Body:
Body Structure, Exterior Panels, Doors, Hood, Trunk, Bumpers, Glass, Interior Trim, Seating, Convertible Top (if applicable for later models, though 850i was coupe/convertible), HVAC System
Maintenance:
Scheduled Maintenance, Oil Changes, Filter Replacements, Fluid Checks and Changes, Spark Plug Service, Belt Replacement
Repair:
Engine Overhaul and Rebuild, Transmission Service and Repair, Brake System Repair, Suspension Component Replacement, Steering Rack Rebuild, Electrical Component Diagnosis and Replacement, Body Panel Repair and Replacement
Diagnostics:
Troubleshooting Guides, Fault Code Interpretation (where applicable for the era), Diagnostic Connector Identification, Step-by-Step Diagnostic Procedures for Common Issues
Specifications:
Torque Specifications, Fluid Capacities, Electrical Schematics, Component Dimensions, Tolerances
Depth:
Comprehensive, covering from basic adjustments and fluid changes to complete engine and transmission rebuilds, detailed electrical system diagnostics, and bodywork procedures. Includes detailed exploded views and component diagrams.
Engine Type:
Naturally Aspirated V12
Displacement:
4.988 L (304.4 cu in)
Bore X Stroke:
84.0 mm x 90.0 mm (3.31 in x 3.54 in)
Valve Train:
SOHC, 2 valves per cylinder (48 valves total)
Horsepower:
300 hp (221 kW) @ 5200 rpm
Torque:
332 lb-ft (450 Nm) @ 4100 rpm
Fuel Delivery:
Bosch Motronic DME (Digital Motor Electronics) with Electronic Fuel Injection (EFI)
Fuel Type:
Premium Unleaded Gasoline (91+ Octane)
ECU:
Dual DME control units (one for each bank of cylinders)
Transmission Type:
4-speed Automatic (ZF 4HP24)
Manual Transmission:
Available in some markets (e.g., Europe) as a 6-speed manual (Getrag Type D), but the 850i typically refers to the V12 with automatic.
Traction Control:
ASC (Automatic Stability Control)
Transmission Fluid Type:
BMW ATF LT71141 or equivalent Dexron III/Mercon (check manual for precise recommendation based on VIN)
Automatic Transmission Fluid Capacity:
Approximately 9.5 liters (10.0 US quarts) for a complete fill, but check manual for dry fill vs. service fill.
Crash Test Data:
As this vehicle predates widespread mandatory crash testing and standardized ratings (like NHTSA 5-star), specific official ratings are scarce. However, BMW vehicles of this era were known for robust construction. The manual would detail passive safety features and structural integrity.
Braking System:
Four-wheel Anti-lock Braking System (ABS), Ventilated Disc Brakes front and rear.
Stability Control:
ASC (Automatic Stability Control) was available, especially on later models.
Airbags:
Driver and Passenger Front Airbags (standard from 1993 onwards, optional earlier).
Seatbelts:
Pre-tensioned front seatbelts, three-point rear seatbelts.
Body Structure:
Reinforced A and B pillars, energy-absorbing crumple zones.
Audio System:
Premium sound systems from brands like Bavaria C or Harman Kardon were available, featuring cassette decks and CD changers (optional). The manual covers basic audio system operation and troubleshooting.
Navigation:
Early BMW navigation systems (e.g., on-board computer with navigation function) were available, often featuring a monochrome display. The manual details its operation.
Cruise Control:
Electronic cruise control was standard.
Telecommunications:
Early integrated mobile phone options might have been available in some markets, but not 'connectivity' as understood today.
Climate Control:
Dual-zone automatic climate control.
Memory Seats:
Power-adjustable front seats with driver's memory function were standard or optional.
Oil Change Interval:
Typically every 10,000-15,000 miles (16,000-24,000 km) or 12 months, though the onboard computer (CC-ID codes) would manage specific service intervals based on driving conditions.
Transmission Fluid Interval:
Recommended every 60,000-100,000 miles (96,000-160,000 km), or as indicated by service history. The manual will detail the correct procedure for checking and changing.
Spark Plug Replacement:
Platinum spark plugs typically rated for 60,000-100,000 miles. Specific type (e.g., Bosch FGR7KQE0) will be in the manual.
Engine Oil Type:
BMW Longlife-98 or Longlife-01 compliant synthetic oil, typically 5W-30 or 5W-40. Specific viscosity and BMW approval number should be confirmed from the manual.
Coolant Type:
BMW Blue Antifreeze/Coolant (G48) or equivalent ethylene glycol-based coolant mixed 50/50 with distilled water.
Engine Oil Capacity:
Approximately 7.5 liters (7.9 US quarts) with filter change.
Common Problems And Fixes:
Engine: Coil pack failures, oil leaks from valve cover gaskets, VANOS issues (later models had it), cooling system component degradation (hoses, water pump). Transmission: Torque converter issues, transmission control unit problems. Electrical: Window regulators, central locking issues, ABS/ASC sensor failures, headlight motor failures, wiring harness degradation (especially in the engine bay). Body: Pop-up headlight mechanism issues, window seal leaks. This manual is essential for diagnosing and repairing these.
Bmw Legacy:
BMW has a long history of producing high-performance luxury automobiles, renowned for their engineering, driving dynamics, and premium build quality. The 8 Series continued this legacy.
E31 Development:
The E31 8 Series was BMW's first completely new platform since the E30 3 Series. It was a radical departure from previous BMW designs, featuring a sleek, wedge-shaped body with pop-up headlights and frameless windows. It was designed as a flagship GT to showcase BMW's technological capabilities.
Engine Development:
The M70 V12 engine was a significant engineering feat, becoming the first mass-produced V12 in BMW history. It was designed to rival the Mercedes-Benz M120 V12 and provide effortless power.
Production Period:
1989-1999
Production Locations:
Dingolfing Plant, Germany
Total Units Produced:
Approximately 30,600 units across all variants (including 840Ci, 850CSi).
Design Awards:
While specific awards for the 850i are not widely documented in the same way as modern cars, its design was critically acclaimed and influential, often cited for its aerodynamic efficiency and timeless elegance. It was a recipient of BMW's design philosophy of 'form follows function'.
Automotive Press Reviews:
Contemporary reviews praised its effortless V12 power, refined ride, and luxurious interior, though criticisms sometimes focused on its size, weight, and the complexity of its systems for the average mechanic.
