IsItAGoodCar
Reliability Guide

Common Problems with the
2020 Subaru Impreza Mk5 (GT/GK)

Mid-cycle models benefit from improved software and build quality but still carry the same infotainment and cooling system weaknesses. These are often the best value examples on the used market.

What changed for 2020

  • •Updated infotainment system
  • •Revised safety equipment options
  • •Improved hybrid system integration

Common MOT watch-outs

  • !Thermo control valve failure becoming more common
  • !CVT fluid degradation on high-mileage cars
  • !Infotainment glitches requiring dealer updates
4
Known Issues
0
Serious
4
Moderate
0
Minor

All Known Issues

Thermo Control Valve Failure

ModerateCooling System

Later Mk5 cars can suffer thermo control valve faults, bringing up dashboard warning lights and poor heater performance without an obvious external coolant leak. Lamps and electrical faults are the most common MOT failure area on the Impreza.

Est. Repair Cost: £400–£900
Warning Signs:

Engine warning light, Cabin heater stays lukewarm, Cooling fans running oddly

What to Inspect:
  • Check heater performance from cold
  • Ask whether the valve has already been replaced
  • Scan the car for stored cooling-related fault codes
Verified by IsItAGoodCar Research TeamUpdated

Infotainment Touchscreen Freezing or Delamination

ModerateElectrics & Electronics

The Starlink-era head unit can become slow, glitchy or develop screen faults such as freezing and ghost touches. Dashboard warning lights and electrical faults dominate the Impreza's MOT failure record, so any persistent electrical warning should be investigated.

Est. Repair Cost: £0–£900
Warning Signs:

Frozen display, Ghost touches, Bluetooth or camera dropout

What to Inspect:
  • Try navigation, media and phone pairing
  • Watch for delayed reverse camera loading
  • Check whether the head unit has already been updated or replaced
Verified by IsItAGoodCar Research TeamUpdated

Suspension Knocking (Top Mounts, Bushes, Drop Links)

ModerateSuspension & Chassis

A long-running owner complaint on Impreza forums is a knock or clunk from the front end on bumps or when turning lock to lock, usually traced to worn strut top mounts, anti-roll bar drop links or wishbone bushes. Suspension is a leading MOT failure category on this model.

Est. Repair Cost: £200–£600
Warning Signs:

Knock or clunk from the front over bumps, Clunking when turning lock to lock, Worn strut top mounts or drop links

What to Inspect:
  • Bounce each front corner listening for knocks
  • Turn the steering lock to lock and listen underneath
  • Ask whether strut mounts or drop links have been replaced
Verified by IsItAGoodCar Research TeamUpdated

Exhaust System Corrosion and Leaks

ModerateExhaust & Emissions

The Impreza's exhaust can corrode under UK winter salt, causing blowing or rattling noises and an MOT failure on exhaust, emissions and leaks. This failure area is well represented in the Impreza's MOT record, especially on higher-mileage cars.

Est. Repair Cost: £250–£600
Warning Signs:

Loud exhaust roar or hissing, Rattling from underneath the car, Failed MOT on exhaust, emissions or leaks

What to Inspect:
  • Listen for an exhaust blow with the engine cold
  • Inspect the silencer and pipes for rust holes
  • Check MOT history for repeated exhaust advisories
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 2020 Subaru Impreza Mk5 (GT/GK)

  • Check if the thermo control valve has been replaced
  • Ask for evidence of CVT fluid servicing
  • Test all safety systems including EyeSight