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Kia Optima IV problems (2015–2020)

All 2 engines of the Kia Optima IV that we have documented have high or critical severity faults: the 1.7 CRDi and the 2.0 / 2.4 GDI and T-GDI (Theta II). None has a «Buy» verdict; the safest option is the 2.0 / 2.4 GDI and T-GDI (Theta II), with a «With caution» verdict.[1][2][3][4]

Outside the engine: Outside the engine, the Kia Optima IV (JF) has three campaigns documented by the DVSA: the plug-in hybrid's high-voltage battery, the camera software of the emergency braking assist, and the brake servo vacuum pump on 2018 to 2020 units. The British press consulted does not cite general reliability problems for the model.[5][6][7]

Kia Optima IV (2015–2020)
Photo: Rutger van der Maar · CC BY 2.0 · Wikimedia Commons. Reference image for this generation.
02468106.8out of 10

Kia Optima IV rating: acceptable reliability

Calculated using only 10 documented faults and their sources: the most serious and frequent faults weigh more. How it is calculated

  • Engine7.1From 6.2 to 8.0 depending on the engine
  • Gearbox10.0No documented faults
  • Suspension8.2Technical inspection (ITV) only: 0.7 times the defects normal for its age
  • Brakes7.91 fault and ITV (technical inspection)
  • Tyres and wheels10.0No documented faults
  • Steering8.3Technical inspection (ITV) only: 0.7 times the defects normal for its age
  • Electrical system7.91 fault
  • Headlights and lights7.8Technical inspection (ITV) only: 0.9 times the defects normal for its age
  • Electronics and infotainment10.0No documented faults
  • Climate control10.0No documented faults
  • Bodywork and interior7.6Technical inspection (ITV) only: 1.0 times the defects normal for its age
  • Airbags and safety7.91 fault

Ranked 10 of 112 among the saloons with solid evidence. See the ranking

The weak points of the Kia Optima IV

  1. 1High severity: Injectors that lose calibration with mileage1.7 CRDi engine · repair €80–€350
  2. 2High severity: High-pressure fuel pump failure1.7 CRDi engine · repair €650–€2,000
  3. 3High severity: Fault in the high-voltage battery management system of the plug-in hybrid OptimaElectrical system
  4. 4High severity: Emergency braking assist camera that may fail to identify stationary vehiclesAirbags and safety
  5. 5High severity: Brake servo tandem vacuum pump fault due to a blocked mesh filterBrakes

Documented engines, from highest to lowest risk

The first label is the most serious fault affecting that engine in this car; the second, our verdict for the versions it is fitted to. Each engine's risk index is calculated only from the faults that affect this car (how we calculate it). We only show engines we have documented with sources: if yours does not appear, we have not analysed it yet. View all engines

See what to check before buying

Outside the engine

3 recalls and campaigns documented, the latest: Tandem pump mesh filter: risk of vacuum pump failure (R/2023/255). See the campaigns for the Kia Optima IV

12 sourcesHow we work

1.7 CRDi

Hyundai/Kia 1.7 CRDi (familia U, código U2 D4FD) · Diesel

In the Optima IV
2015–2018[8]
Name
1.7 CRDi VGT
Faults that affect it
5 · 2 of high or critical severity
Risk index on this car
38
Moderate risk

Verdict for the version it uses

  • 1.7 CRDi U2 (D4FD, 115-141 hp, sold in Spain 2010-2018)2010–2018 · 115–141 hp · D4FD

    With caution

    An engine with no documented catastrophic failure, but with a specific and persistent cold-weather problem (turbo, diesel filter, glow plugs) and the emissions-system (EGR, DPF) and injection (injectors, high-pressure pump) wear usual in a common rail diesel of its generation; it is worth checking the maintenance history for these items, especially if the car is used in winter or on short urban journeys.[9][10]

Faults that affect the Optima IV

  1. High severityFrequency: OccasionalInjectionInjectors that lose calibration with mileageThe 1.7 CRDi's common rail injectors can lose their factory calibration with mileage or because of poor-quality diesel, causing vibration at idle and black smoke from the exhaust; the unburned fuel that ends up diluting the oil also means oil change intervals need to be shortened.Repair (garage): €80–€350
  2. High severityFrequency: OccasionalFuelHigh-pressure fuel pump failureThe common rail system's high-pressure pump can fail at around 80,000-100,000 km, with hard cold starts, an uneven idle and power loss; if ignored, there is a risk of metal debris contaminating the rest of the injection system.Repair (garage): €650–€2,000Appears at around 80,000 km
  3. Medium severityFrequency: CommonTurboSeized turbo actuator (VGT) and power loss when coldIn cold weather (below 10-15 °C), the 1.7 CRDi can suddenly lose power and even stall; the engine restarts after a few seconds. A documented fault that combines the turbo's variable-geometry actuator with the diesel filter and the glow plugs.Repair (garage): €150–€1,200
  4. Medium severityFrequency: CommonEmissions controlEGR valve clogged with carbon depositsAs in most diesels of its generation, the 1.7 CRDi's EGR valve builds up carbon deposits with urban use and short cold journeys, which causes power loss and an uneven idle and can switch on the engine or emissions warning light.Repair (garage): €60–€350
  5. Medium severityFrequency: CommonEmissions controlParticulate filter (DPF) clogged in urban useIn cars used mainly on short urban journeys (under 15-20 km), the 1.7 CRDi's particulate filter never completes its regeneration cycle and becomes saturated with soot; according to the source consulted, it is the most common problem of this engine in the Hyundai ix35.Repair (garage): €250–€1,200

Optima IV 1.7 CRDi pageAll versions and faults of the 1.7 CRDi

2.0 / 2.4 GDI and T-GDI (Theta II)

Safest option

Hyundai/Kia Theta II 2.0 and 2.4 (MPI, GDI and 2.0 T-GDI; G4KD, G4KE, G4KJ and G4KH) · Petrol

In the Optima IV
2015–2020[2][11]
Names
2.4 GDI · 2.0 T-GDI GT
Faults that affect it
2 · 1 of high or critical severity
Risk index on this car
20
Low risk

Verdict for the versions it uses

  • It shares a family with the engines in the US campaigns, but we have found no European campaign for the 2.4 GDI: the German guide to the Sorento III knows of no cases in Germany, although it does not rule them out, and recommends scrutinising the history closely, especially on US imports. It also has the carbon build-up typical of direct injection.[1][2][3]

  • 2.0 T-GDI (G4KH, 245-280 hp, turbo, from 2016)since 2016 · 245–280 hp · G4KH

    With caution

    We have not located European campaigns or European sources documenting faults specific to this version. It shares a family with the rest of the Theta II and, being direct injection, is exposed to the intake carbon build-up described in the page: check the VIN and the maintenance history.[2][4]

Faults that affect the Optima IV

Only those that affect the versions and years that this car used. The 2.0 / 2.4 GDI and T-GDI (Theta II) has 3 documented faults in total.

  1. Medium severityFrequency: OccasionalIntakeCarbon build-up on the intake valves of direct-injection Theta II enginesAs with any direct injection, petrol does not wash over the intake valves and deposits build up. A German guide to the Sorento XM 2.4 GDI associates them with loss of power and higher consumption and recommends using cleaning additives regularly.
  2. High severityFrequency: RareTimingTiming chain stretchThe chain can stretch if oil changes are stretched out or the car only does short trips. The German guide to the Sorento XM 2.4 describes it as a not widespread problem and the ix35 one finds no cases; if the chain jumps or breaks, the engine is damaged.

Optima IV 2.0 / 2.4 GDI and T-GDI (Theta II) pageAll versions and faults of the 2.0 / 2.4 GDI and T-GDI (Theta II)

Faults of the Kia Optima IV outside the engine

Suspension, brakes, tyres, electronics and the rest of the car. They occur with any engine.

What the MOT inspection finds on the Kia Optima IV

Official Dutch MOT (APK) inspection data: 1,062 inspections of 444 cars registered between 2016 and 2018, compared with cars of the same age.

  • Suspension and axles· counts in the score

    Defects in 1.5% of inspections; in cars of its age, 2.4%.

    Fewer defects than average

  • Brakes· counts in the score

    Defects in 2.3% of inspections; in cars of its age, 2.9%.

    Average

  • Steering· counts in the score

    Defects in 0.4% of inspections; in cars of its age, 1%.

    Fewer defects than average

  • Headlights and lights· counts in the score

    Defects in 10.2% of inspections; in cars of its age, 11.8%.

    Average

  • Rust and bodywork· counts in the score

    Defects in 0.1% of inspections; in cars of its age, 0.1%.

    Average

  • Exhaust and emissions

    Defects in 0.4% of inspections; in cars of its age, 1%.

    Fewer defects than average

  • Fluid leaks

    Defects in 0.5% of inspections; in cars of its age, 0.9%.

    Fewer defects than average

  • Glass, wipers and mirrors

    Defects in 3.1% of inspections; in cars of its age, 3.6%.

    Average

  • Tyres and wheels· depends mostly on maintenance

    Defects in 15.1% of inspections; in cars of its age, 15.4%.

    Average

The inspection measures wear and the defects visible at a periodic check, not engine or electronics failures. Source: RDW Open Data (public domain). How we calculate it · opendata.rdw.nl

Checklist for buying a used Kia Optima IV

Check the advert or the paperwork to see which engine the car has and go through its section. Each point comes from a documented fault; you can tick them off as you inspect.

If it has the 1.7 CRDi (2015–2018)

Injectors that lose calibration with mileage

High severity

High-pressure fuel pump failure

High severity

Seized turbo actuator (VGT) and power loss when cold

Medium severity

EGR valve clogged with carbon deposits

Medium severity

Particulate filter (DPF) clogged in urban use

Medium severity

If it has the 2.0 / 2.4 GDI and T-GDI (Theta II) (2015–2020)

Carbon build-up on the intake valves of direct-injection Theta II engines

Medium severity

Timing chain stretch

High severity

Wear parts for the Kia Optima IV

Brakes, wiper blades, pollen filter and battery, searched for this model. The exact part number depends on the engine and year: confirm it with the registration plate or VIN.

Affiliate links: if you buy from these shops, MotorFiable may receive a commission at no cost to you. Check compatibility against the registration plate or VIN before ordering. Affiliate links

Buying a Kia Optima IV?

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Own a Kia Optima IV? Tell us what faults you have had, at what mileage and how much you paid. Report your fault.

Frequently asked questions

Is the Kia Optima IV reliable?

All 2 engines of the Kia Optima IV that we have documented have high or critical severity faults: the 1.7 CRDi and the 2.0 / 2.4 GDI and T-GDI (Theta II). None has a «Buy» verdict; the safest option is the 2.0 / 2.4 GDI and T-GDI (Theta II), with a «With caution» verdict. Outside the engine, the Kia Optima IV (JF) has three campaigns documented by the DVSA: the plug-in hybrid's high-voltage battery, the camera software of the emergency braking assist, and the brake servo vacuum pump on 2018 to 2020 units. The British press consulted does not cite general reliability problems for the model.

Which Kia Optima IV engine is the most reliable?

Among the 2 engines we have documented, none has a «Buy» verdict; the safest option is the 2.0 / 2.4 GDI and T-GDI (Theta II), with a «With caution» verdict. It shares a family with the engines in the US campaigns, but we have found no European campaign for the 2.4 GDI: the German guide to the Sorento III knows of no cases in Germany, although it does not rule them out, and recommends scrutinising the history closely, especially on US imports. It also has the carbon build-up typical of direct injection.[1][2][3]

What problems does the Kia Optima IV have apart from the engine?

Outside the engine, the Kia Optima IV (JF) has three campaigns documented by the DVSA: the plug-in hybrid's high-voltage battery, the camera software of the emergency braking assist, and the brake servo vacuum pump on 2018 to 2020 units. The British press consulted does not cite general reliability problems for the model. The most important documented faults are: fault in the high-voltage battery management system of the plug-in hybrid Optima (electrical system, high severity), emergency braking assist camera that may fail to identify stationary vehicles (airbags and safety, high severity) and brake servo tandem vacuum pump fault due to a blocked mesh filter (brakes, high severity).[5][6][7]

What faults does the Kia Optima IV have?

The most important by severity and frequency, on the engines we have documented, are: injectors that lose calibration with mileage (1.7 CRDi, high severity), high-pressure fuel pump failure (1.7 CRDi, high severity), seized turbo actuator (VGT) and power loss when cold (1.7 CRDi, medium severity), EGR valve clogged with carbon deposits (1.7 CRDi, medium severity) and particulate filter (DPF) clogged in urban use (1.7 CRDi, medium severity).

What is the best year to buy a Kia Optima IV?

According to our rating by year, the best is 2020 (7.9/10); the worst rated is 2017 (7.1/10). Each year's rating counts only the engines sold that year and the faults that affect those units: open each year to see what changes.

Does the Kia Optima IV have recalls?

Yes: we have documented 3 campaigns for the Kia Optima IV, such as tandem pump mesh filter: risk of vacuum pump failure (R/2023/255) (2023). Check with your VIN at the official service centre whether yours has been done.[5]

Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. Kia Sorento III (2014 – 2020) – Typische Probleme & KrankheitenGebrauchtwagenberater · Buying guide or workshop · published 3 May 2022 · consulted 8 October 2026 · in German
  2. Hyundai Theta engineWikipedia · Encyclopedia · consulted 8 October 2026
  3. Kia Sorento II (2009 – 2014) – Typische Probleme & KrankheitenGebrauchtwagenberater · Buying guide or workshop · published 7 April 2023 · consulted 8 October 2026 · in German
  4. What Parts Of The Engine Are The Most Prone To Carbon Buildup?SlashGear · General press · published 10 May 2026 · consulted 8 October 2026
  5. Check a vehicle recall (recalls dataset since 1992)DVSA (Reino Unido) · Official body · consulted 5 October 2026
  6. Kia Optima (2016-2019) reviewAuto Express · Motoring press · published 12 February 2018 · consulted 5 October 2026
  7. Kia Optima saloon (2016-2019) - Reliability & safetyCarbuyer · Motoring press · published 25 August 2016 · consulted 5 October 2026
  8. Kia OptimaWikipedia · Encyclopedia · consulted 27 September 2026
  9. Kia Sportage 1.7 Crdi Problemas | Fallos y averías más frecuentesTotalRenting · Buying guide or workshop · consulted 27 September 2026 · in Spanish
  10. Hyundai iX35 1.7 Crdi Problemas | Fallos y averías más frecuentesTotalRenting · Buying guide or workshop · consulted 27 September 2026 · in Spanish
  11. Kia OptimaWikipedia (alemán) · Encyclopedia · consulted 8 October 2026 · in German
  12. Hyundai ix35: Zahnriemen oder Steuerkette?repareo.de · Other source · consulted 8 October 2026 · in German