IsItAGoodCar
Reliability Guide

Common Problems with the
2018 BMW i3 (I01)

We've identified 2 known issues that can affect the 2018 BMW i3 (I01). None are considered critical, but they're worth knowing about before you buy.

2
Known Issues
0
Serious
1
Moderate
1
Minor

All Known Issues

REx Engine Corrosion & Misfires

ModerateEngine

The Range Extender (a 650cc scooter engine) can suffer from internal corrosion or stale fuel if not used regularly. It is sensitive to spark plug and oil condition.

Est. Repair Cost: £500–£1,500
Warning Signs:

REx engine refusing to start, Rough running or "Drivetrain" error when the REx is active, Strong smell of petrol or oil

What to Inspect:
  • Request a manual start of the REx (Maintenance Mode) during the test drive
  • Check the oil and spark plug service history
  • Look for fuel pressure sensor recall completion
Verified by IsItAGoodCar Research Team

12V Auxiliary Battery Failure

MinorElectrics & Electronics

The small 12v battery powers the car's computers. When it fails, the car throws dozens of unrelated error codes and may refuse to engage the high-voltage system.

Est. Repair Cost: £150–£250
Warning Signs:

Random "High Voltage System" errors, Car won't "Ready" or unlock, Screen glitches

What to Inspect:
  • Check the date code on the 12v battery (should be replaced every 4-5 years)
  • If original, budget for immediate replacement
Verified by IsItAGoodCar Research Team

Buying Tips for 2018 BMW i3 (I01)

  • ✓On REx models, ensure the petrol engine starts and runs smoothly; many are never used and can seize or corrode internally
  • ✓Check the custom narrow Bridgestone Ecopia tyres for wear; they are expensive and can wear quickly on the rear
  • ✓Inspect the CFRP door sills and the plastic body panels for any cracks or structural damage
  • ✓Verify the high-voltage battery capacity via the hidden service menu to ensure it hasn't degraded excessively
20172019–2022
Check a 2018 BMW i3 (I01) by Registration