BMW M550i
Third-generation hot-V eight-cylinder — electric wastegates, 350 bar injection, forged internals. In Sport mode a rich V8 growl with turbo hiss; in Comfort barely audible. Throttle response noticeably more direct than TU/TU2 thanks to electric wastegates. The most reliable N63 variant, but the hot-V architecture remains: short oil change intervals (max. 8,000 km) with 0W-40 are mandatory, not an optional extra. Valve stem seals and timing chain guides remain as residual risk at high mileage.
M5 for the Sensible — No Bad Thing
462 hp V8 biturbo, hushed rumble in Comfort, clear bark in Sport. A quiet achiever in a sharp suit — understated saloon with M5-grade thrust.
Engine Weaknesses 5
The fundamental design with valve stem seals is retained. At very high mileages (>150,000 km) and aggressive use the seals can suffer thermal wear. Repair costs €3,300–3,800 (approx. 6–8 hours' work, engine removal required).
Symptoms: Increased oil consumption at very high mileages, slight blue smoke on cold start or after extended standstill, oil deposits in the exhaust
The plastic timing chain guide rails are sensitive to degraded engine oil. Extended oil change intervals (BMW Longlife) accelerate degradation. Complete engine removal (~40 labour hours) required; preventive replacement at >150,000 km is advisable.
Symptoms: Rattling on cold start, engine warning light, occasionally loud clattering with heavily degraded oil
The hot-V design also generates residual heat in the turbo oil feed lines after shutdown in the TU3. Immediate shutdown after full-load driving causes carbon deposits in the oil lines. Cases with fully coked lines at 60,000 km have been documented.
Symptoms: Power loss under load, occasional turbo whistling, in extreme cases blue smoke after a motorway run
350-bar direct injection without intake valve flushing — carbon deposits on intake valves are inevitable even in the TU3. Walnut blasting every 60,000–80,000 km is recommended; cost €400–900.
Symptoms: Power loss at part throttle, occasional rough idle, increased fuel consumption
The TU3 generation uses a separate cooling circuit for the turbochargers. Coolant loss documented at 14,000–15,000 km, often without visible leak. Turbo coolant hoses under the covers are a frequent leak point.
Symptoms: Coolant warning light without visible puddle, periodic coolant loss, coolant smell after shutdown
Vehicle Weaknesses 20
BMW recalled several G60 models from 2023–2024 due to faulty cell contacts in the high-voltage battery. A defect can cause discharge and present a fire risk.
BMW recalled the 5 Series G60/G61 because a misrouted cockpit wiring harness can be damaged during pollen filter replacement. A short circuit can cause fire. KBA 16187R.
The AdBlue dosing system crystallises during long standstill or at low temperatures. Fault code 26F500 appears. NOx sensor is a classic wear point. Repair is expensive.
The flex disc (Hardy disc) in the drivetrain often cracks before 100,000 km. BMW sometimes covers it under goodwill. Replacement including prop shaft can cost 2,000 €.
A signal fault in the motor position sensor of the integrated brake system can deactivate the hydraulic brake assist. ABS and DSC fail. BMW replaces the entire IBS free of charge.
The M5 G90 weighs around 2,435 kg as a PHEV — approximately 500 kg more than the F90 predecessor. The extra weight affects dynamics and causes understeer in tight corners. The system is still very new and long-term data is lacking.
Related BMW PHEV models such as the X5 50e show CCU (Combined Charging Unit) failures below 2,000 km. Whether the M5 G90 uses identical components and is affected remains unclear — the model is too new for reliable data.
Traffic sign recognition, TPMS sensors, digital instrument cluster, and lane/parking assistance failures are frequently reported. Usually resolved by software updates.
Various suspension components (top mounts, drop links, control arms) wear out. Air suspension on the G31 Touring is a known weak point. Rear lighting fails due to wiring breaks.
The G30's iDrive system tends to crash and restart sporadically. Navigation, Bluetooth, and CarPlay are intermittently unavailable. Software updates usually only help temporarily.
Especially on M Sport vehicles, the front brakes squeal when braking lightly. BMW acknowledged the issue and released a revised brake system. No safety risk.
Some G60 drivers report occasional messages that recuperation is not working. After software updates BMW also significantly changed the hybrid drivetrain characteristics, leading to owner complaints.
The new BMW OS 9 operating system in the G60 still has various software bugs: voice control fails, assistant systems falsely deactivate, smartphone pairing is unstable.
On the G60 with M Sport suspension, noises occur at full lock or when parking. BMW dealers recommend shock absorber replacement as the fix — whether the top mount or damper is the root cause has not been conclusively determined.
A quiet rattle from the steering wheel area at 30–60 km/h on uneven road. Cause is a loose airbag pot, not the steering itself. Issue appears to be known but no official service bulletin has been issued.
Wireless CarPlay disconnects from the system sporadically; eSIM shows connection error on startup. Digital key sometimes cannot be set up. Issue occurs reproducibly for several i5 owners — often every third journey.
When steering with M Sport suspension, especially on the 520d xDrive, noises come from the steering area. Dealers in isolated cases recommended shock absorber replacement, which didn't reliably resolve the issue.
Several G60 owners report noticeable steering play and imprecise steering feel, resolved by steering rack replacement under warranty.
G60 owners report Spotify connection drops, incorrect navigation position, and driver assistance failures. Software instability with OS9 systems.
The additional weight of around 500 kg compared to the F90 M5 places considerable strain on the G90's braking system. Despite recuperative braking, mechanical brakes need replacing earlier.
Reports & Tests
16 owner complaints filed with NHTSA (2017–2023). Most reported: Seat Belts (4), Airbags (3), Body Structure (2).