Here's a list I found for 850i maintenance items. Hope it helps someone.
BMW 850I Maintenance Issues
Built 1991 to 1997
Approx. 2,000 cars per year for all of North America
Options
Automatic Transmission (4 speed originally; became 5 speed)
6 Speed standard transmission
Models: I became Csi
Wheels: forged 17 inch available (cast 16 inch base)
Concerns
Mileage—lower miles help reduce risk of high cost repairs
Warranty—reduces cost of ownership
Service—ask for service records to ensure car has been well maintained
Winter use—salt exposure plus chance of accidents
What goes wrong|? Clues
clutch fails due to engine torque & driver’s use
coils fail and can take out computer LHM
engine management computer fails with coil; limp-home-mode (LHM)
D-K Motors (throttle-by-wire) LHM
intake manifold gaskets cold idle is very rough; heat + expansion: idle smooths out
valve train banjo bolt
EDC active shocks leak; replacement cost is high
6 Speed Transmission hard to shift (vague) changed later to Getrag
front shock bushings fail with 17 inch rims
rear shock mounts fail “ “ “ “
engine rebuild expensive! US$15,000 +
oxygen sensors in exhaust LHM
overheating in hot environment pop hood to vent heat; later cars electric fan
seats get out of sync; rub on console
sunroof gets out of sync; missing paint?
change box (driver’s door) fails
window switch lights burn out (switches in door)
Recommendations
get service records (has regular service been done?)
check VIN to determine real mileage; ask about extended warranty
check condition of exhaust, clutch, coils, D-K motors (original or replaced?)
4 wheel alignment; check for chassis damage
replace ignition coils at 50K-60K miles to prevent damage to computers
D-K motors have been disassembled, cleaned and repaired by mechanics
Dave L
BMW 850I Maintenance Issues
Built 1991 to 1997
Approx. 2,000 cars per year for all of North America
Options
Automatic Transmission (4 speed originally; became 5 speed)
6 Speed standard transmission
Models: I became Csi
Wheels: forged 17 inch available (cast 16 inch base)
Concerns
Mileage—lower miles help reduce risk of high cost repairs
Warranty—reduces cost of ownership
Service—ask for service records to ensure car has been well maintained
Winter use—salt exposure plus chance of accidents
What goes wrong|? Clues
clutch fails due to engine torque & driver’s use
coils fail and can take out computer LHM
engine management computer fails with coil; limp-home-mode (LHM)
D-K Motors (throttle-by-wire) LHM
intake manifold gaskets cold idle is very rough; heat + expansion: idle smooths out
valve train banjo bolt
EDC active shocks leak; replacement cost is high
6 Speed Transmission hard to shift (vague) changed later to Getrag
front shock bushings fail with 17 inch rims
rear shock mounts fail “ “ “ “
engine rebuild expensive! US$15,000 +
oxygen sensors in exhaust LHM
overheating in hot environment pop hood to vent heat; later cars electric fan
seats get out of sync; rub on console
sunroof gets out of sync; missing paint?
change box (driver’s door) fails
window switch lights burn out (switches in door)
Recommendations
get service records (has regular service been done?)
check VIN to determine real mileage; ask about extended warranty
check condition of exhaust, clutch, coils, D-K motors (original or replaced?)
4 wheel alignment; check for chassis damage
replace ignition coils at 50K-60K miles to prevent damage to computers
D-K motors have been disassembled, cleaned and repaired by mechanics
Dave L