IsItAGoodCar
Reliability Guide

Common Problems with the
2018 Hyundai Ioniq (Hybrid/PHEV)

We've identified 3 known issues that can affect the 2018 Hyundai Ioniq (Hybrid/PHEV). 1 of these are serious faults that could be expensive to repair.

3
Known Issues
1
Serious
2
Moderate
0
Minor

All Known Issues

Clutch Actuator Fluid Leak

SeriousGearbox & Transmission

An internal leak in the hydraulic clutch actuator can lead to an electrical short and is a known fire risk. Most affected cars were recalled.

Est. Repair Cost: £0–£1,200
Warning Signs:

Hybrid system warning light, Jerky gear changes, Fluid visible under the car

What to Inspect:
  • Check recall status for "Clutch Actuator"
  • Inspect the actuator area for oily residue
Verified by IsItAGoodCar Research Team

12V Battery Drain & Deep Sleep Bugs

ModerateElectrics & Electronics

The auxiliary 12V battery can drain if the car is left for several days. On earlier models, this was often due to the car failing to enter a "deep sleep" mode, sometimes exacerbated by frequent Bluelink app pings or third-party tracking apps.

Est. Repair Cost: £120–£200
Warning Signs:

Car completely unresponsive, Remote locking fails, Clock resets, 12V battery dies if HV battery is below 20%

What to Inspect:
  • Age and health of the 12V battery
  • Presence of a "Battery Reset" button (on newer models)
  • Software version of the BMC
Verified by IsItAGoodCar Research Team

DCT Hesitation & Shudder

ModerateGearbox & Transmission

The 6-speed DCT can feel hesitant or "shudder" when pulling away, particularly in cold weather or stop-start traffic.

Est. Repair Cost: £300–£1,500
Warning Signs:

Delay when pressing the accelerator, Jerky behavior at low speed, Unpleasant vibration during take-up

What to Inspect:
  • Perform several low-speed starts from cold
  • Check for gearbox software updates in the service history
Verified by IsItAGoodCar Research Team

Buying Tips for 2018 Hyundai Ioniq (Hybrid/PHEV)

  • ✓Check for the "Battery Reset" button on 2019+ facelift models, which allows self-jump-starting from the hybrid battery
  • ✓Verify all recalls (Main Power Relay and Clutch Actuator) have been completed by a dealer
  • ✓Test the DCT for smoothness at low speeds; it should be more direct than a Prius CVT but can be jerky if cold
  • ✓Inspect the boot for dampness, which can affect the 12V battery or hybrid modules
Check a 2018 Hyundai Ioniq (Hybrid/PHEV) by Registration