What got replaced
Owners who name the part that was replaced mention the sensor (10 reports), the spark plugs (8 reports), the ignition coils (5 reports) and the catalytic converter (5 reports).
Recalls and investigations
One recall on the engine covers the 2020 model year. A recall on the same system isn't always the same failure, so read the defect text.
21V-259Apr 13, 2021
Engine
Kia Motors America (Kia) is recalling certain 2020-2021 Soul, and 2021 Seltos vehicles equipped with 2.0L Nu MPI engines. The piston oil rings may not have been properly heat-treated, which may result in engine damage.
Risk and remedy
Risk: A damaged engine may stall, increasing the risk of a crash. In addition, oil may leak onto hot exhaust components, increasing the risk of a fire.
Remedy: Kia will notify owners, and dealers will inspect and, if necessary, replace the engine, free of charge. In addition, Kia will deploy Piston Ring Noise Sensing System (PNSS) software. The recall began June 11, 2021. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC209.
NHTSA investigations into the engine on the Soul
AQ25-001opened Aug 6, 2025
Engine And Engine Cooling · model years 2021 to 2023
Kia 25v099 piston oil ring recall effectiveness. Closed dec 18, 2025.
NHTSA summary
On August 6, 2025, the Office of Defect Investigation (ODI) opened Audit Query (AQ) 25001 to assess the implementation of Kia America, Inc.âs (Kia) remedy program for Safety Recall 25V099, involving incorrectly manufactured piston oil rings which may damage the engine causing a loss of motive power or fire. This AQ was opened in response to consumer complaints alleging of an ineffective remedy, inconsistent inspection results to determine whether an engine replacement was needed, and the unavailability of recall remedies. On August 11, 2025, an Information Request (IR) was issued to Kia requesting: 1) why the inspection test was revised from requiring a âcoldâ engine to a âwarmâ engine; 2) why the recall remedy was suspended from April 30, 2025 to May 7, 2025; 3) how Kia notified customers of the recall remedy suspension and the need to re-test engines that failed the âcoldâ engine test; 4) the number of post-recall remedy complaints alleging engine or other engine related failures; and 5) the warranty coverage Kia is offering to vehicles that passed either inspection tests. On September 10, 2025, Kia responded to NHTSAâs IR: Kia reported the change in temperature from âcoldâ to âwarmâ engine testing was done to increase accuracy. The inspection test uses diagnostic tools that detects abnormal engine vibrations to identify damaged engines. From the initial launch of the Technical Service Bulletin (TSB) on April 4, 2025 through April 28, 2025, âcoldâ
DP22-003opened Sep 12, 2022
Engine · model years 2012 to 2020
Loss of motive power. Closed dec 12, 2023.
NHTSA summary
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints indicating that the subject vehicles were experiencing rapid loss of engine oil due to oil drain plug back outs, resulting in loss of motive power and/or catastrophic engine damage. Additional complaints were provided which alleged that the oil drain pans lack sufficient structural integrity and are susceptible to cracking. The petition itself can be reviewed at NHTSA.gov under ODI number 11481745. On September 12, 2022, the Office of Defects Investigation (ODI) opened Defect Petition (DP22-003) to evaluate the Petitionersâ request. The Petitioners have provided additional complaints within four supplemental letters dated January 31, 2023, March 21, 2023, May 23, 2023, and August 4, 2023. ODIâs evaluation included the review and analysis of the complaints and supporting information submitted by the Petitioners, as well as additional complaints submitted directly to NHTSA which referenced either the oil drain plug or a crack in the oil pan. After reviewing the available data, ODI has not identified evidence that would support opening a defect investigation into the oil drain pan as
EA21-003opened Dec 22, 2021
Engine · model years 2012 to 2016
Engine fires. Closed feb 5, 2024, led to recall 23V-877.
NHTSA summary
On March 29, 2019, the Office of Defects Investigation (ODI) opened two Preliminary Evaluations (PE19-003 on Hyundai and PE19-004 on Kia) to broadly investigate incidents of non-crash fires (regardless of origin or operational status of the vehicle) on various model year Hyundai and Kia vehicles. During the PE investigations, Hyundai and Kia issued several recalls to address vehicle fires, including those due to engine failures involving various engine types. The remedies for the engine failure recalls typically involve engine inspection (to detect existing damage), and if necessary, engine replacement. Additionally, both manufacturers have been installing an engine control software modification known as Knock Sensor Detection Software (KSDS) which is intended to detect impending engine failure, alert the driver, and limit engine power (to lessen likelihood of engine failure).KSDS is being installed under recalls and non-safety field actions, and both companies have extended limited engine warranties (see recall files). On December 22, 2021, ODI upgraded PE19-003 and PE19-004 to this Engineering Analysis (EA21-003, covering both Hyundai and Kia) to evaluate the scope of the prior recalls related to engine failures/fires and the efficacy of the recall remedies for the recalls, as well as the long-term viability of related programs and non-safety field actions being conducted by Hyundai and Kia. The former issue involved approximately 550,000 MY 2013 Hyundai Elantra, MY
PE19-004opened Mar 29, 2019
Electrical · model years 2010 to 2015
Non-crash vehicle fires. Closed dec 22, 2021, led to recall 20V-088.
NHTSA summary
During this Preliminary Evaluation (PE), the Office of Defects Investigation (ODI) assessed the scope, frequency and potential safety-related consequences of non-crash vehicle fires caused by both engine failures and failures of other vehicle systems/components in model year (MY) 2011-2014 Kia Optima, MY 2011-2014 Kia Sorento and MY 2010-2015 Kia Soul vehicles equipped with Theta II, Gamma, Nu and Lambda II engines (approximately 1.7 million vehicles). ODI also reviewed field and other data on other Kia vehicles (approximately 3.6 million additional vehicles) equipped with the same engines used in the above-mentioned vehicles.As a result of this PE, Kia has issued NHTSA Recalls 20V-750 and 21V-844 to address potential engine failures and fires in certain Kia vehicles equipped with various engine types.Additional information on these and other related recall actions is available in the downloadable version of this resume available at NHTSA.gov.In addition, ODI has upgraded this PE to an Engineering Analysis (EA) 21-003 which will focus on potential recall scope concerns and recall remedy concerns related to the engine failure-related recalls mentioned above and conducted previously.See the EA21-003 Opening Resume available at NHTSA.gov for more information.Also available in the downloadable version of this resume is a list of the reference numbers for the 444 ODI reports, or Vehicle Owner Questionnaires (VOQs), cited above which ODI received through mid-November 2021.Note that
DP18-003opened Aug 21, 2018
Electrical · model years 2010 to 2015
Non-crash vehicle fires. Closed may 10, 2019, led to recall 18V-907.
NHTSA summary
In a letter dated June 11, 2018, the Center for Auto Safety (CAS) petitioned the National Highway Traffic Safety Administration (NHTSA) to initiate a safety defect investigation into non-collision related fires on model year (MY) 2011-2014 Kia Optima and Sorento, and Hyundai Sonata and Santa Fe vehicles. In a letter dated July 24, 2018, CAS requested that MY 2010-2015 Kia Soul vehicles be added to the petition. CAS stated that there is a higher number of complaints to NHTSA regarding non-crash fires on these vehicles compared to other similar vehicles. The Office of Defects Investigation (ODI) had already opened Recall Queries (RQ17-003 and RQ17-004) on all Kia and Hyundai vehicles equipped with Theta II engines for engine failures that may cause stalling and fires.The queries cover most of the petition subject Optima, Sorento, Sonata, and Santa Fe vehicles but not any of the subject Soul vehicles.On August 21, 2018, ODI opened a Defect Petition (DP18-003) to evaluate whether to grant or deny the CAS petition. ODI sent Information Request letters to Kia and Hyundai (September and October 2018) requesting information on all engine and non-engine related fires in the petition vehicles.ODI performed extensive analysis on the information obtained from Kia and Hyundai. During the DP18-003 analysis, Kia and Hyundai each initiated three additional safety recalls related to engine compartment fires on certain petitioned and non-petitioned vehicles (nearly 740,000 total vehicles: Reca
What owners paid
12 of the 75 reports quote a price. Each dot is one quote. The middle half runs $315 to $5,000.
$0k$2k$4k$6k$8k
When it happens
The middle half of failures fell between 21,700 and 94,815 miles, from the 45 reports that gave a mileage.
220
621
1022
523
1324
2725
1226