KNOWN FAULTS · BMW

Known faults for the BMW Serie 8 (G14/G15/G16).

2018–2026 · Diesel / Petrol

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

3 known faults with sources

Engines: 840d (B57) (Diesel)

B-engine coolant leaks and EGR coolerCooling / EGR

Engine / equipment: B47 and B57 diesel and B48 and B58 petrol modular engines (BMW from 2014–2015 and MINI from 2014)
Period mentioned: 2014–2026
Symptoms: Coolant loss with a low-level warning, coolant or oil residue at the rear of the engine; on diesels, internal coolant loss with no visible leak (EGR cooler).
Possible cause described: On the B48 and B58 the water pump leaks (from its weep hole) and the oil filter housing with heat exchanger can crack; on 2017–2021 B58s the crankcase ventilation valve also fails. On the diesels the EGR cooler can leak internally and mix coolant with soot: BMW issued a recall over the risk of the intake manifold catching fire.
Check for the garage: Check the coolant level, look for leaks under the water pump and at the oil filter housing, and on diesels confirm by VIN whether the EGR cooler campaign was done.
Cost cited in the source: Water pump: relatively cheap to replace; oil filter housing: more labour-intensive; EGR cooler: free if covered by the campaignA rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: 80,000–195,000 km. This is not a maintenance interval and does not predict a failure.

Engines: 840d (B57) (Diesel) · 840i / M850i (Petrol) · M8 (S63, 4.4 V8) (Petrol)

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.

Engines: M8 (S63, 4.4 V8) (Petrol)

N63 / S63 oil consumption and chainEngine (lubrication / timing)

Engine / equipment: N63 4.4 V8 twin-turbo (550i, 650i, 750i, X5/X6 50i, M550i) and its M version, the S63 (M5, M6, M8, X5 M, X6 M)
Period mentioned: 2008–2026 (most cases on 2008–2013 N63)
Symptoms: High oil consumption, blue or white smoke on start-up, misfires, chain rattle and a battery that drains.
Possible cause described: The turbos sit inside the engine's V and the heat hardens valve stem seals, hoses and plastic chain guides. In 2014 BMW launched the N63 “Customer Care Package” (injectors, chain, seals, battery). The 2012 N63TU reduced oil consumption without eliminating it. On the S63, rod bearings are also worth monitoring.
Check for the garage: Oil consumption test, confirm by VIN that the Customer Care Package was done and listen for the chain on a cold start.
Cost cited in the source: Valve stem seals: approx. €6,500–8,300 (converted from dollars); chain: several thousand eurosA rough figure from the original database, not an up-to-date quote.