"Is the 7 Serisi 730i reliable, and what should you check?"
When buying a used BMW 7 Series 730i 2021 (G11/G12 facelift), the most frequently mentioned issue is cooling system failures. Oil consumption and leaks are also commonly reported.
Engine: B48
B48B20 · 730i · Used in this car from 2019-2022
Known engine issues
Cooling systemEarly versions of this engine were equipped with short-lived cooling system pipes that often burst, but later plastic was replaced with rubber and the problem went away. Also on the forum they often complain about the short-lived water pump, radiators and coolant expansion tank cap.
Oil consumptionCompared to its predecessors, B48 units are not as prone to oil consumption, but closer to 100,000 km the valve stem seals usually harden and consumption appears. Also worth noting are regular leaks from the oil filter housing, it needs to be monitored.
Floating idleFloating idle speed or regular appearance of lean mixture errors indicate failure of the fuel tank ventilation valve. But it is inexpensive.
+2 more issues on the engine detail page
Known issues and risks
Listed from most frequently reported, each with its source.
Cooling system failures
Often reported
Reported issues with cooling circuit components (electric water pump, thermostat, connections) often cause intermittent overheating or temperature warning messages at higher mileage.
Cooling
Oil consumption and leaks
Often reported
Commonly reported on BMW 2.0 engines (B48): both above-average oil consumption and local leaks (gaskets, oil pan, oil filter housing, valve cover) may occur. These issues can lead to frequent oil level drops between services and oil stains under the vehicle.
Engine Internal
VANOS / Injectors and power loss
Often reported
On the B48 engine, clogged VANOS solenoids or valves are reported to cause irregular variable valve timing, resulting in power gaps, idle fluctuation, or check engine light; some users also note dirty/clogged injectors leading to misfires.
Engine Internal
Timing chain / tensioner noise
Often reported
Some users report rattling or tapping noises from the timing area on cold start. This may relate to tensioners, timing chain, or guides. While more prominent on N20 engines, similar reports exist on B48 versions, especially early models.
Timing chain
Turbo / boost issues
Often reported
Failures reported in turbocharger or wastegate actuators, causing power loss, whistling/grinding noise, and boost pressure fault codes.
Turbo
BMW 7 Serisi 730i technical specs
BMW 7 Serisi 730i (2021): boot 515 L; fuel use 7 l/100 km (urban 8,4 l/100 km · extra-urban 6,2 l/100 km); 0–100 in 6.2 s.
Boot capacity
515 L
Fuel consumption
7 l/100 km (urban 8,4 l/100 km · extra-urban 6,2 l/100 km)
What to look for when buying a BMW 7 Series 730i?+
When buying a 2021 730i, check service history, test drive, and look for engine/transmission warnings. Most reported issues: cooling system failures; oil consumption and leaks; VANOS/injectors and power loss.
What are the common problems of BMW 7 Series 730i?+
Most reported issues: cooling system failures; oil consumption and leaks; VANOS/injectors and power loss.
Is the BMW 7 Series 730i reliable?+
Rather than a simple yes/no, it's best to weigh the proven pros and cons together. This page lists 5 verified findings.
How does Carbeak collect data?+
The cards on this page are derived from Difetti fault database records; brand, fuel, engine, and generation compatibility between source and target vehicle are verified. Topics with insufficient evidence are not shown.