Kia 25V099 Piston Oil Ring Recall Effectiveness
Opened Aug 6, 2025
Closed Dec 18, 2025
On August 6, 2025, the Office of Defect Investigation (ODI) opened Audit Query (AQ) 25001 to assess the implementation of Kia America, Inc.’s (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 ‘cold’ engine to a ‘warm’ 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 ‘cold’ 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 NHTSA’s IR: Kia reported the change in temperature from ‘cold’ to ‘warm’ 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, ‘cold’ engine testing resulted in a higher-than-expected failure rate when compared to the pre-recall warranty claim rate. This discrepancy led Kia to re-evaluate its inspection test and found that performing the inspection on a ‘cold’ engine can result in imprecise test results due to normal cold-start vibrations. Kia revised the inspection to ‘warm’ engine testing to minimize vibration interference. Kia sampled the field and performed a comparative analysis between ‘cold’ and ‘warm’ engine testing, and validated that ‘warm’ engine testing was more accurate in identifying damaged engines. Kia also reported the suspension of the recall remedy was due to a software error in the diagnostic tool, which was introduced in concert with the April 29, 2025 launch of the TSB that revised the inspection from ‘cold’ to ‘warm’ engine testing. The software error resulted in all inspection tests reporting false positives for a damaged engine. On April 30, 2025, Kia suspended the remedy until May 7, 2025, which was when the software error was corrected with the release of the latest TSB and software update. The recall remedy remains available to eligible customers. Kia reported owners were not mailed letters concerning the suspension to the recall remedy. Kia reasoned since it resolved the issue faster than it would have taken to draft and mail letters, Kia did not want to create unnecessary customer confusion involving an issue that would have already been addressed upon receipt of a letter. Kia also determined that mailing letters about re-testing engines was unnecessary since those vehicles were already at the dealer awaiting engine replacement. In most instances, Kia Customer Care agents would respond to customer inquiries related to the recall, including remedy availability, dealer issues, and questions about differing test results. Kia provided ODI a review of engine related consumer complaints received on post recall-remedied vehicles. Kia did not find any common patterns or trends related to those complaints following completion of the recall, as the complaints included issues that were unrelated to the subject defect. To aid in the diagnosis of whether a complaint is related to the recall, the remedy includes the installation of a software program, the Piston-ring Noise Sensing System (PNSS), that monitors the engine for unusual noise patterns (an indicator of potential damage to the piston oil rings), and alerts the customer by flashing the check engine light and setting Diagnostic Trouble Code (DTC) P1327. Kia confirmed that it is not offering any specific warranty coverage for this recall. Instead, Kia has instructed dealers to replace the engine, at no cost to the customer, with no time or mileage limitation, following the installation of the PNSS software and the presence of DTC P1327. On September 4, 2025, Kia issued Subsequent Repair Action (SRA) # SC336YZ, which provided engine diagnosis and replacement instructions for vehicles with a potentially related complaint following completion of the recall. Under this SRA, customers whose vehicles set DTC P1327 will have their engine replaced. If DTC P1327 is not set and it is unclear whether the issue is related to the recall, dealers are instructed to contact Kia's Technical Assistance Center to ensure the issue is appropriately handled. Kia notes that any issues determined to be unrelated to the recall are subject to the 10-year / 100,000-mile Powertrain warranty for original purchasers and a 5-year / 60,000-mile Limited Basic Warranty for subsequent purchasers. In summary, Kia identified the insufficiencies of its initial inspection test that led to a pause to its recall campaign, explained why it did not mail letters to affected customers about the paused campaign or revised inspection test, reviewed existing consumer complaints that did not identify any potential trends related to the recall, and identified its warranty coverage for any vehicles exhibiting qualifying engine symptoms. After review of Kia’s response to the IR, ODI has determined that no further action from Kia is necessary at this time, and ODI will close this AQ investigation accordingly. The Agency reserves the right to take additional action if warranted by future circumstances. To review the ODI reports cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.
ENGINE AND ENGINE COOLING:ENGINE:HARD PARTS INTERNAL/MECHANICAL