Used car guide

2015 Kia RIO diesel: common problems and MOT failures

What MOT testers find on the diesel Kia RIO first registered in 2015 (diesel cars only): we looked at the 6,164 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

6,164MOTs of 2015 diesel cars, done in 2023–2025
69%pass first time (all 2015 cars: 74%)
8,000typical miles a year
1.6×the usual rate for brake discs

What goes wrong more than usual on a 2015 Kia RIO diesel?

Parts flagged at MOT more often on the 2015 Kia RIO diesel than on all cars registered in 2015.

  • Brake discs1.6× usual
    Kia RIO
    19.8% All 2015 cars
    12.5%

    Failed outright at MOT: 2.1%, against 0.9% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £150–£350 our estimate

    At the viewing: Look through the wheel at the brake disc: a deep lip at the edge or heavy scoring means they're worn. Feel for judder when braking.

  • Rigid brake pipes2.8× usual
    Kia RIO
    5.6% All 2015 cars
    2%

    Failed outright at MOT: 0.8%, against 0.3% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £100–£400 our estimate

    At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.

  • Braking performance2× usual
    Kia RIO
    6.1% All 2015 cars
    3%

    Failed outright at MOT: 1.9%, against 1.1% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £100–£350 our estimate

    At the viewing: On a quiet road, brake firmly from about 30mph. The car should stop straight without pulling.

  • Engine oil leaks2× usual
    Kia RIO
    5.1% All 2015 cars
    2.5%

    Failed outright at MOT: 0%, against 0.1% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £80–£600 our estimate

    At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

  • Engine warning light2.5× usual
    Kia RIO
    3.7% All 2015 cars
    1.5%

    Failed outright at MOT: 3.7%, against 1.5% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

Better than most

Coil springs: 0.4% here, against 4.3% of all 2015 cars. Shock absorbers: 0.9% here, against 4.6% of all 2015 cars.

Common 2015 Kia RIO diesel MOT failures and advisories

The share of 2015 Kia RIO diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    36% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Brakes
    33% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Suspension
    20% of testsRough price £120–£400

    At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

  • Lights and electrics
    15% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Wipers, windscreen and mirrors
    8% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

  • Oil and fluid leaks
    6% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

Known faults on the 2015 Kia RIO diesel

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

  • Dashboard rattles

    All engines

    Dashboard rattles can be bad, and fixing them can mean taking the dashboard out.

    At the viewing: Drive on a rough road and listen.

    Source: Auto Express: used Kia Rio (Mk3, 2011-2016) review

  • Stop-start, hill hold and ESP faults

    All engines

    The stop-start can work erratically, and some owners have had problems with hill hold and ESP.

    At the viewing: Watch stop-start at junctions, and check that hill hold holds on a slope.

    Source: Auto Express: used Kia Rio (Mk3, 2011-2016) review

Questions to ask the seller before buying a 2015 Kia RIO diesel

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Any recent work on the brake discs? (Flagged at MOT 1.6× as often on the 2015 Kia RIO diesel as on other cars the same age.)
  2. Any recent work on the rigid brake pipes? (Flagged at MOT 2.8× as often on the 2015 Kia RIO diesel as on other cars the same age.)
  3. Any recent work on the braking performance? (Flagged at MOT 2× as often on the 2015 Kia RIO diesel as on other cars the same age.)
  4. Can I see the service history and receipts for any big jobs?

Looking at a Kia RIO?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Kia RIO compared

YearMOT testsMost flagged
2023199Tyres 8%
20224,885Tyres 15%
20217,219Tyres 20%
202010,019Tyres 22%
201914,358Tyres 25%
201816,943Tyres 29%
201723,978Tyres 31%
201626,231Tyres 32%
201432,699Tyres 33%
201329,473Brakes 34%
201226,746Brakes 35%
201120,317Suspension 50%
201017,923Suspension 54%
200914,107Suspension 54%
20085,967Suspension 59%
20073,499Suspension 57%
20062,776Suspension 56%
20051,507Suspension 53%
2004860Lights and electrics 50%
2003486Lights and electrics 52%
2002280Brakes 57%
2001–Too few tests

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Kia RIO cars first registered in 2015. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score