KNOWN FAULTS · BMW

BMW Serie 8 (G14/G15/G16) 840i / M850i common problems.

2018–2026 · Petrol

Sources are not verified in real time and no entry confirms that your car is affected.

2 known faults with sources

Applies if: Only if fitted with the automatic gearbox described in the record.

ZF 8HP oil level, leaks and harsh shiftsAutomatic gearbox

Engine / equipment: ZF 8HP automatic gearbox in rear-wheel-drive BMWs from 2009 (1 to 8 Series and X: F20, F30, F10, G20, G30, X3, X5…)
Period mentioned: 2009–2026
Symptoms: Harsh shifts (especially engaging D and 1st to 2nd), slipping or jerking; oil leaks from the pan, the mechatronic connector sleeve or the seals.
Possible cause described: BMW's diagnostic guide says an incorrect oil level is a frequent cause of shift complaints and asks for it to be checked every time, even with no visible leaks; the pan can be damaged by impacts. The sealing sleeve between gearbox and mechatronic lets oil through to the connector. The oil, sold as lifetime, degrades.
Check for the garage: Check the oil level with the official procedure (correct temperature and engine running), look for leaks at the pan, connector sleeve and seals, inspect the pan for impact damage and review adaptation values with ISTA.
Cost cited in the source: Oil change with pan and filter: maintenance; sleeve or seals: minor repair; mechatronic: expensive repairA rough figure from the original database, not an up-to-date quote.

Applies if: US bulletin (SIB 11 04 26) for BMWs with the B58 or XB1 engine built between 2018 and 2021; in Europe, ask the dealer.

The electronic oil level measurement from inside the car does not work or freezes (BMW with B58 or XB1, 2019–2021)Engine

Engine / equipment: BMW with the B58 3.0 six-cylinder and the XB1 plug-in hybrids (X3 M40i, X4 M40i, X5/X6 40i, X5 45e, X7 40i, 740i, 745e and 840i)
Period mentioned: 2019–2021 (US model years)
Symptoms: When the oil level measurement is started from the car menu (usually after an oil change), it does not work or freezes between 15% and 30% and returns to the start screen. Oil pressure monitoring and the continuous oil level check while driving still work.
Possible cause described: A software fault in the engine computer (DME). BMW fixes it by programming the car to I-level S18A-26-07-518 or later (SIB 11 04 26).
Check for the garage: Ask the BMW workshop to check the software level (I-level) and update it if it is older than S18A-26-07-518.
Cost cited in the source: No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.