NHTSA complaint #11753365

Owner complaint summary

The engine lost power while driving, and the vehicle entered a reduced-power mode. The check engine light began flashing, and the engine made a loud knocking noise during acceleration. A diagnostic scan showed code P1326 (Knock Sensor Signal Range/Performance). The knock sensor was replaced, and the engine oil was refilled after discovering an oil leak. The vehicle operated normally for a short time, but the same symptoms returned. The vehicle is available for inspection. The vehicle suddenly lost power while traveling approximately 70 mph on the highway, making it difficult to maintain speed and safely keep up with traffic. This created a risk of being struck by other vehicles or causing an accident. The problem has since recurred during normal driving. The problem has been reproduced multiple times. A diagnostic scanner consistently identified code P1326. The knock sensor was replaced and the engine oil was replenished, but the same symptoms returned after several trips. The vehicle has not yet been inspected by a Hyundai dealership. The vehicle has been inspected by the owner and a family mechanic who replaced the knock sensor and identified an engine oil leak. It has not yet been inspected by Hyundai, law enforcement, or an insurance representative. There were no warning lights or messages indicating low engine oil or an oil leak before the failure occurred. I had the engine oil changed approximately one month before the incident. While driving on the highway at approximately 70 mph, the vehicle suddenly lost power, the check engine light began flashing, and the engine started making a loud knocking noise. After inspecting the vehicle, we discovered it had an engine oil leak and the oil level was low. Before the loss of power, there were no warning signs that the engine was losing oil or that there was an oil leak.