Cooling system problems
Often reportedFrequent leaks or failures are reported in cooling system components such as water pump, thermostat, or expansion tank.
Cooling
When buying a used BMW 5 Series 520i 2020 (G30 / G31 / F90), the most frequently mentioned issue is cooling system problems. Oil leaks and consumption are also commonly reported.
Engine varies by trim; verify the engine code on the listing.
Listed from most frequently reported, each with its source.
Frequent leaks or failures are reported in cooling system components such as water pump, thermostat, or expansion tank.
Cooling
Oil leaks from gaskets are commonly reported on B48 engines, requiring frequent oil top-ups. The most cited areas are the oil filter housing, valve cover gasket, and oil pan; if unresolved, it can lead to critically low oil levels and engine damage.
Engine Internal
In some B48 engine examples, startup noises or rattling from the timing system may be heard, indicating wear or failure of the belt/chain tensioner. If neglected, it can lead to chain stretch and timing slip risk.
Timing chain
Injector failure or clogging, and less commonly high-pressure pump issues, are reported; this can cause hard starting, rough idle, power loss, and increased fuel consumption.
Fuel System
Some B48 units report turbocharger anomalies: wastegate rattle, loss of boost pressure, or premature wear. Typical symptoms include power loss, noise at idle or acceleration, and in severe cases, turbo replacement may be required.
Turbo
Same trim, different year
We only publish claims we can verify. Cards come from Difetti fault records matched to this vehicle on brand, fuel, engine and generation.