Positioning:
BMW's flagship luxury grand tourer, targeting high-performance enthusiasts and the luxury market.
Competitors:
Ferrari 412, Porsche 928, Mercedes-Benz SL-Class (R129)
Design Philosophy:
Aerodynamic coupe styling, luxurious interior, powerful V12 engine, advanced technology for its era.
Manual Purpose:
To provide professional-level diagnostic, repair, and maintenance guidance for the BMW 850CSi (E31).
Engine Coverage:
V12 (M70B50, S70B56)
Transmission Coverage:
6-speed manual, 4-speed automatic (limited)
Chassis And Body:
Frame, suspension, steering, brakes, body panels, interior trim
Electrical System:
Wiring diagrams, ECU diagnostics, lighting, power accessories, sensors
Estimated Page Count:
1500+
Manual Type:
Service Repair Workshop Manual
Engine Mechanical:
Complete engine teardown, rebuild, component specifications, timing, cooling system
Engine Management:
Fuel injection (DME), ignition system, sensor diagnostics, ECU troubleshooting
Transmission And Drivetrain:
Manual gearbox overhaul, automatic transmission servicing, driveshafts, differential
Brakes And Suspension:
ABS system diagnostics, brake pad/rotor replacement, shock absorber/strut service, alignment procedures
Steering And Wheel Alignment:
Power steering system, steering rack repair, wheel alignment specifications
Climate Control System:
HVAC system diagnosis and repair, refrigerant handling
Body And Interior:
Panel removal/installation, door mechanisms, convertible top (if applicable), interior trim components
Safety Systems:
Airbag system diagnosis (SRS)
Routine Maintenance:
Oil changes, filter replacements, spark plug service, fluid checks and top-offs
Diagnostic Troubleshooting:
Step-by-step fault finding for all major systems, symptom-based diagnostics
Component Replacement:
Detailed instructions for replacing all major and minor components
Engine Rebuild:
Complete engine teardown, measurement, and reassembly procedures
Electrical Diagnostics:
Wiring diagram interpretation, component testing, troubleshooting electrical faults
Wheel Alignment:
Specific alignment angles and adjustment procedures
Brake System Overhaul:
Calipers, rotors, lines, and ABS unit service
Depth:
Comprehensive (from basic maintenance to complete engine/transmission rebuilds and advanced diagnostics)
Diagnostic Codes:
Includes specific OBD-I diagnostic codes and interpretation for the E31 platform
Torque Specifications:
Detailed torque values for all fasteners
Clearances And Tolerances:
Precise measurements for engine and drivetrain components
Searchable:
Yes (text-searchable)
Scalability:
High (suitable for printing specific sections or the entire manual)
Binding Recommendation:
Comb binding or three-hole punch for workshop use
Recommended Paper:
Durable, heavy-weight paper for workshop environments
Completeness Level:
Full workshop manual coverage, not excerpted chapters
Engine Code:
M70B50 (initially), S70B56 (850CSi)
Displacement:
5.0L (M70B50) / 5.6L (S70B56)
Horsepower:
300 hp (M70B50) / 375 hp (S70B56)
Torque:
332 lb-ft (M70B50) / 406 lb-ft (S70B56)
Induction:
Multi-point fuel injection (Bosch Motronic DME)
Fuel Type:
Premium Unleaded Gasoline (91+ octane)
Ignition System:
Distributorless ignition (2 coils per cylinder bank)
Cooling Medium:
BMW Blue Antifreeze/Coolant (G48 ethylene glycol based)
Type:
6-speed manual (Getrag 420G)
Type:
4-speed automatic (ZF 4HP24)
Manual Clutch:
Hydraulically operated, dual-mass flywheel
Manual Gearbox Fluid:
API GL-4 or GL-5, viscosity 75W-90
Automatic Gearbox Fluid:
Dexron III (or equivalent approved fluid)
Crash Test Results:
Not officially rated by NHTSA or IIHS under modern standards, but built to high BMW safety standards of the era.
Traction Control:
ASC+T (Automatic Stability Control and Traction)
Anti Lock Brakes:
ABS (Anti-lock Braking System) with Electronic Brake Force Distribution (EBD)
Stability Control:
Included as part of ASC+T
Airbags:
Driver and front passenger airbags
Seatbelts:
Three-point inertia-reel seatbelts with pretensioners
Body Construction:
Reinforced chassis and safety cell structure
Audio System:
BMW Bavaria C Business or Professional CD/Cassette system, optional premium sound systems (e.g., Harman Kardon)
Navigation:
Optional BMW Navigation System (early GPS technology)
Cruise Control:
Standard electronic cruise control
Parking Assistance:
Optional rear parking sensors (Park Distance Control)
Telephone:
Optional integrated car phone
Headlights:
Pop-up / Hidden Xenon headlights
Windows:
Electric windows with one-touch up/down function
Oil Change Interval:
Every 10,000 miles or 12 months, whichever comes first (synthetic oil recommended)
Spark Plug Replacement:
Typically at 60,000 miles (depending on plug type)
Coolant Flush:
Every 2 years or 30,000 miles
Engine Oil Capacity:
Approx. 7.5 liters (8.0 US quarts) with filter
Engine Oil Viscosity:
SAE 5W-30 or 5W-40 Synthetic recommended
Power Steering Fluid:
Pentosin CHF 11S or equivalent hydraulic fluid
Common Electrical Problems:
Door module failures, wiring harness degradation, ABS/ASC sensor issues, alternator failure
Common Mechanical Problems:
Coolant leaks (especially hoses and thermostat housing), rear main seal leaks, starter motor issues, VANOS unit (on later M70/S70 variants)
Common Fuel System Issues:
Fuel pump failure, clogged fuel injectors (especially on S70B56)
Bmw Heritage:
BMW, known for 'The Ultimate Driving Machine', has a long history of producing sophisticated and performance-oriented vehicles.
E31 Introduction:
The E31 8 Series was introduced in 1989 as a successor to the E24 6 Series coupe, representing BMW's foray into the high-end luxury sports coupe segment.
850Csi Development:
The 850CSi, launched in 1992, was the most potent version, featuring an enlarged 5.6L V12 engine and significant chassis upgrades, developed by BMW M GmbH.
Production Period:
1989-1999 (8 Series overall), 1992-1996 (850CSi specifically)
Production Volume Csi:
Approximately 1,510 units worldwide
Automotive Design:
Widely praised for its timeless and aerodynamic design, considered a modern classic.
Engineering Excellence:
Recognized for its complex V12 engine and sophisticated chassis engineering.
Owner Satisfaction:
While specific ratings are dated, owners often praise its build quality, performance, and luxury.
