BMW 520d
Modular four-cylinder diesel, successor to the N47. Timing chain now at the front of the engine — the N47's biggest problem is eliminated. EGR and DPF remain wear items.
Reliable Diesel
Modern four-cylinder diesel — frugal and long-lived, but not a driver's engine.
Engine Weaknesses 6
Early B47 engines (2014–2016) are prone to premature chain elongation. The tensioner can no longer compensate. Rattling on cold start is the typical warning sign before chain snap and engine damage.
Symptoms: Metallic rattling or clattering on cold start; subsides after warm-up; in advanced cases audible during driving; MIL may illuminate
Overheating and leaking EGR coolers can vaporise glycol and trigger self-ignition. BMW recalled affected vehicles. If coolant enters the combustion chamber, hydraulic lock and engine damage are possible.
Symptoms: Coolant level drops without visible leak; whitish smoke from exhaust; rough idle; MIL; limp mode; rarely smoke from engine bay
With frequent short-trip use the DPF never reaches sufficient regeneration temperature. Soot accumulation blocks the filter and the engine enters limp mode. Long-term, oil level rises due to fuel intrusion.
Symptoms: MIL with message 'Particulate filter fault'; severe power loss; increased fuel consumption; black exhaust smoke on cold start; oil level rising
Common-rail injectors operate at up to 2,500 bar and wear at higher mileages. Knocking noise on cold start and misfires on individual cylinders. Replacement is complex and expensive.
Symptoms: Knocking noise on cold start; fault code 'injection quantity out of tolerance' or 'cylinder X misfire'; stumbling; increased consumption
From about 150,000 km onwards, failures of the electronic thermostat and electric water pump become more frequent. Overheating without early warning is possible. Replacing both parts simultaneously is recommended.
Symptoms: Coolant temperature rises unusually quickly or too high; heater blows cold; fault codes relating to the water pump; rarely a sudden failure
Primarily urban short-trip use causes the EGR valve to coke up. Power loss and increased emissions.
Symptoms: Power loss, rough running, engine check light, black smoke
Vehicle Weaknesses 21
On the G31 Touring with optional air suspension, leaking rear bellows are reported. Car sags after several days of standing, compressor runs continuously. Repair cost around 1,600 € per unit.
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.