Used BMW M850

What to know before buying: BMW M850

From 1 forum thread and 2 press tests · updated 11/10/2026

What the reviews say

• Forum participants describe the 1991 850Ci as an impressive car, but several consider it very expensive to maintain.[1]one source
• Forum advice cautions against using a 1991 850Ci as the sole daily car and also notes its very low ground clearance.[1]one source
• The source shows only one drivetrain complaint for the 2020 M850i xDrive, so it cannot establish how widespread the issue is.[3]one source

Typical faults

• One complaint for the 2020 M850i xDrive reports severe drivetrain shudder under acceleration.[3]one source

  2020–2020

• A forum post mentions electronics problems on the 1991 850Ci but gives no affected components, symptoms, or frequency.[1]one source

  1991–1991

• An M8 repair source says ordinary 8 Series door locks can wear over time and produce a metallic rattle without impairing door closure.[2]one source

Which engine and version to take

• The sources do not support recommending any M850 engine; the engine in the forum's 1991 850Ci is not identified.[1][3]

What to avoid

• Do not automatically apply the M8's S63B44 problems to the M850; the source covers an M8 engine, not an M850 engine.[2]one source

What to check at the inspection

• During a 2020 M850i xDrive test drive, accelerate progressively and check for severe drivetrain shudder.[3]one source
• On a 1991 850Ci, test all electrical equipment; the source mentions electronics problems without identifying specific components.[1]one source
• Check the 8 Series door locks by opening and closing every door and listening for a characteristic metallic rattle.[2]one source

Verdict

Sources

1. [1]forum.zr.ru — BMW 850. Брать - не брать? - ВЫБОР АВТО - Форум · forum
2. [2]bmw-e.ru — Основные неисправности BMW M8 серии · press
3. [3]carcomplaints.com — drivetrain problems - 2020 BMW M850i Xdrive · press

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