NHTSA Complaint #11693683 — 2018 HYUNDAI SONATA

In December 2024, my 2018 Hyundai Sonata went into limp mode after the knock sensor was triggered. This happened when my son was driving home from school. I took it to my local mechanic and he said the car was low on oil. We put more oil in it and reset the sensor. In March, the knock sensor was triggered and it again went into limp mode while my son was driving back to school. We took it into a shop and it was again low on oil. Oil was added and then the sensor was reset. The sensor went off again later in March and our mechanic told us to take it to Hyundai and have it checked for the rod bearing issue common with this model and year of Hyundai. He cleared the error and when I contacted the dealer, they said they needed the warning lights on to do a diagnosis. The car was driven for 4 months and the knock sensor went off again. I took it to the dealer and they checked the bearing clearance and it passed the test. The oil was also low and the dealer recommended doing a combustion chamber clean. I spent $564 to get the combustion chamber cleaned. Less than three weeks later, the knock sensor went off again. I took it to the dealer and they measured the bearing clearances and they came back as "passed". I elevated the complaint to Hyundai and they responded that they will defer to the dealer technicians' recommendations and findings and did not offer to do anything to help. The dealer the drove the car to see if they could trigger the knock sensor which was unsuccessful. After expressing my disappointment and dissatisfaction, the dealer said there was nothing else they could do and the car was returned to me. I am concerned with the safety of this vehicle as entering Limp Mode on a highway represents a safety issue that Hyundai does not seem to be concerned about.