BMW 740e G11 Reliability - Problems & Costs

The first plug-in hybrid 7 Series, pairing a 2.0 B48 turbo four with an electric motor and 9.2 kWh battery. Considered a tax-efficient flagship in many EU markets between 2016 and 2019, when it was replaced by the inline-six 745e. Combines limousine luxury with PHEV complexity.· more· less

Lower tax than V8 in many EU markets B48 engine is reasonably solid

Four-cylinder feels small for a 7 Hybrid + air suspension repair costs

Buy if: You want a luxury flagship with low company-car tax and full BMW dealer history with verified hybrid battery health.

Avoid if: You expect six-cylinder smoothness or cannot budget for hybrid module, air suspension, or electronics repairs.

Maintenance costs

€1,350 - €2,400/year

15,000 km/year

Fixed costs

€850-1,400

Risk buffer

€500-1,000

Common Problems

High-voltage battery degradation

€4,000 - 12,0001 of 6

9.2 kWh pack loses capacity, reducing electric range and forcing reliance on the petrol engine · more· less

The 9.2 kWh lithium-ion battery (around 6.9 kWh usable) degrades over time and use. Real-world electric range was modest from new (around 30-40 km) and many older 740e examples now manage 20-25 km. Cell-level repair by specialists runs roughly €4,000-6,000. Full pack replacement at a BMW dealer can exceed €10,000-12,000 once labor and certification are included. Always have the battery health (SOH) read on diagnostics before purchase. Check that charge/discharge cycles complete without faults.

SME / EME hybrid module faults

€2,500 - 7,0002 of 6

Battery safety module or electric motor electronics throw faults, sometimes opening HV contactors · more· less

The SME (Battery Safety Module, inside the HV battery) and EME (Electric Motor Electronics) communicate with each other; if either errors, the contactors may open and the car cannot use or charge the HV battery. Owners report the 12V battery then drains because there is no alternator (the electric motor acts as the generator). Diagnostics are dealer-specific. Module replacement plus programming typically lands between €2,500 and €7,000 depending on which unit is at fault.

Air suspension leaks and compressor wear

€1,200 - 4,0003 of 6

Rear air springs leak overnight; compressor overworks and fails, typically after 100,000-150,000 km · more· less

Self-leveling rear air suspension is standard on the 740e. Springs perish, valve blocks leak, and the compressor wears as it tries to keep up. A single air spring runs €500-900 fitted; compressor replacement (often a Wabco unit) is around €1,000-1,500. If multiple components go at once, bills of €3,000+ are realistic. Listen for the car sitting low overnight and check for level errors in iDrive.

12V battery drain and electronics quirks

€300 - 1,2004 of 6

12V battery dies more easily on a PHEV with no traditional alternator; many electronic gremlins · more· less

Because the 740e has no conventional alternator, the 12V battery is recharged via the high-voltage system. Faults anywhere in that chain (SME, EME, DC-DC converter) leave the 12V depleted, triggering a cascade of warning lights and locking issues. AGM 12V batteries typically last 4-6 years and must be coded to the car when replaced. Budget €300-500 for a properly registered battery; more if the underlying cause is a module fault.

B48 plastic coolant components

€400 - 1,5005 of 6

Plastic thermostat housing and coolant pipes weep, typically after 80,000-130,000 km · more· less

The B48 four-cylinder is one of BMW's more reliable modern petrol engines but suffers from age-related coolant leaks at plastic peripherals: thermostat housing, water pump, and coolant manifold. Symptoms are slow coolant loss and minor weeping rather than catastrophic failure. Replacement is straightforward at an independent BMW specialist for €400-800; dealer prices climb toward €1,500 once OEM parts and labor are included.

Charging port and onboard charger faults

€500 - 2,5006 of 6

Charge port lock actuator sticks and the 3.7 kW onboard charger occasionally fails · more· less

Owners report sporadic charging faults: the port lock fails to release, charging aborts partway, or the onboard charger triggers an error code. Port lock replacement is typically €500-900; the onboard charger (KLE) is more involved, often €1,500-2,500 with coding. Issues are not universal but worth testing on every cable type the seller has access to.

Flagship comfort with PHEV repair exposure

The B48 engine itself holds up reasonably well, but the 740e adds layers of risk: the high-voltage battery, hybrid electronics (SME/EME), air suspension, and the cascade effects of a PHEV with no traditional alternator. Verify dealer history, a recent diagnostic scan, and SOH (state of health) of the HV battery before committing.

Pre-Purchase Inspection Checklist

General checks

Service history
Complete BMW dealer or specialist records essential, with attention to hybrid system inspections.
Tires
Check tread depth, age, and uneven wear. Heavy car wears tires quickly.
Cold start
Start engine completely cold. Listen for unusual sounds from the engine bay.
Test drive
Minimum 30 minutes mixing electric, hybrid, and motorway driving to load all systems.

Specific for this vehicle

Diagnostic scan with SOH readout
Insist on a BMW-tool scan that reports HV battery state of health and any stored SME/EME codes.
Full charge cycle on Type 2 cable
Plug in and verify the car completes a charge without error. Test that the port unlocks normally.
Air suspension level overnight
Check if the car sits level after being parked for several hours. Sagging on one corner indicates a leak.

+ 3 more checksShow less

EV-only drive segment
Drive 10-15 km in pure EV mode. Verify range remaining matches indicated SOH and engine does not start unprompted.
Check coolant level and condition
Inspect both engine and hybrid system coolant reservoirs. Look for weeping at plastic housings.
12V battery age and coding
Ask when the AGM 12V was last replaced and whether it was registered to the car.

Recalls and Technical Service Bulletins

High-voltage battery cell fault risk (selected 2017-2018 build dates) Verify completed

Takata airbag inflator Verify completed

Contact BMW with the VIN to verify all recalls have been completed, especially any related to the high-voltage battery.

Warranty Status

Factory warranty (2 years) Expired on all 740e G11

HV battery warranty (8 years / 100,000 km) Expired or near expiry on most cars

Rust perforation (12 years) Active on most cars

Most 740e G11 examples are now outside the original 8-year hybrid battery warranty. Confirm any remaining coverage with BMW using the VIN before purchase.

Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.

This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.

BMW 740e G11

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