IsItAGoodCar
Reliability Guide

Common Problems with the
2014–2020 BMW i8 (I12)

We've identified 3 known issues that can affect the 2014–2020 BMW i8 (I12). None are considered critical, but they're worth knowing about before you buy.

3
Known Issues
0
Serious
3
Moderate
0
Minor

All Known Issues

Door Strut Failure

ModerateBodywork & Rust

The lightweight carbon-fibre and aluminium dihedral butterfly doors rely on high-pressure gas damper struts hidden within the front wings. Over time, gas pressure escapes, causing the doors to drop unexpectedly or feel excessively heavy to lift.

Est. Repair Cost: £200–£400
Warning Signs:

Door drops shut or fails to stay locked at its highest open detent, Noticeably heavy effort required to lift door upwards, Creaking or groaning sound from wing strut cavity during door movement

What to Inspect:
  • Open both doors on level ground and confirm they remain fully upright without sagging
  • Check gas struts inside front wing aperture for oil misting or leakage
Verified by IsItAGoodCar Research Team

REx Fuel Pressure Sensor

ModerateFuel System

The petrol fuel tank is pressurized and sealed to prevent petrol vapour emissions during pure EV driving. The electronic fuel tank pressure relief sensor or tank vent solenoid valve can fail, causing the iDrive system to lock the fuel filler flap closed.

Est. Repair Cost: £300–£600
Warning Signs:

"Preparing for refuelling: please wait" message hangs continuously on dash, Fuel filler flap remains locked and will not pop open at petrol stations, Check engine warning light with EVAP fuel tank pressure sensor fault codes

What to Inspect:
  • Press fuel flap release button next to driver footwell and verify flap pops open within 5 seconds
  • Check boot emergency pull cord release mechanism for fuel flap
Verified by IsItAGoodCar Research Team

Steering Rack Knock

ModerateSteering

The lightweight electromechanical steering rack mounted to the front carbon-aluminium subframe develops internal clearance play between the steering rack bar and thrust piece, producing hollow metallic knocking over minor road imperfections.

Est. Repair Cost: £1,000–£2,000
Warning Signs:

Rattling or clunking feedback felt through steering wheel over cobbles and low-speed road ruts, Vague or loose on-centre steering response, Metallic knocking when rocking steering wheel side to side with engine off

What to Inspect:
  • Test drive over speed bumps and coarse asphalt listening for front-end hollow knocking
  • Inspect front steering tie rods and check if revised steering rack thrust piece bush has been fitted
Verified by IsItAGoodCar Research Team

Buying Tips for 2014–2020 BMW i8 (I12)

  • Check the high-voltage battery health using the iDrive hidden menu to see the 'Max Kappa' reading, indicating degradation.
  • Inspect the spectacular dihedral 'butterfly' doors; ensure the gas struts hold them up securely, as they weaken over time.
  • Test the air conditioning to ensure it blows ice cold; the A/C compressor also cools the high-voltage battery, and a failure can be catastrophic.
  • Look for any cracks or damage to the CFRP (carbon fibre) body shell or sills, as repairs require highly specialized, expensive composite work.
  • Verify the petrol engine starts seamlessly when the battery is depleted or when switching to 'Sport' mode.
  • Check the condition of the incredibly narrow, bespoke 'eco' tyres; they offer little kerb protection for the large alloy wheels.
Check a 2014–2020 BMW i8 (I12) by Registration