Hyundai Tucson knocking problems

Filed Oct 27, 2026 · Engine · MN

My name is [XXX]. My husband, [XXX], and I purchased a 2017 Hyundai Tucson (VIN: [XXX]) from a Hyundai dealership in 2023 with 53,920 miles for our daughter to commute to school. The vehicle now has approximately 77,940 miles, and she is still attending school. Since purchasing the vehicle, we have consistently returned to the same Hyundai dealership for regular maintenance, trusting its professionals to keep the vehicle safe and reliable. While driving on the freeway, our daughter suddenly lost engine power. The vehicle slowed down and would no longer accelerate. Thankfully, she managed to exit the highway before it stopped completely. Highway patrol assisted her in moving the vehicle to the roadside. The Check Engine Light and oil-pressure warning light came on, the engine made a pronounced knocking sound, and it would no longer run. We believe these symptoms closely resemble the engine defect described in Hyundai's Recall 209 (the federal safety agency 21V‑727), involving connecting-rod-bearing failure in certain 2017 Tucson vehicles. Hyundai Motor America denied our request for assistance, stating that our VIN is not included in the recall and that no warranty coverage applies. We respectfully question whether vehicles experiencing the same or substantially similar defect may have been excluded from the recall. We request a technical investigation into why our vehicle was excluded and whether its engine failure is related to the recalled defect. This was a serious safety concern, not merely a repair expense. Our daughter could have suffered a serious accident had she been unable to exit the freeway safely. We are grateful she escaped without injury. We respectfully request that Hyundai reconsider its decision, review the vehicle's maintenance and diagnostic records, and investigate the engine failure. If the failure is related to the recalled defect, we ask Hyundai to cover the cost of engine repair or replacement. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 14, 2026 · Engine · FL

While driving on the highway 65 mph in our 2019 Hyundai Tucson AWD, the vehicle suddenly experienced a severe power loss, loud engine knocking, engine light flashing, and the car in limp mode. This caused a terrifying hazard. We exited to safety, the car was towed and is at a Hyundai dealership. It pulled a diagnostic engine trouble code P1326 (Knock Sensor Detection System). The dealership confirmed the code, but is refusing to replace the engine under the Hyundai Engine II Class Action Settlement without an out-of-pocket 'combustion cleaning' fee, which, as seniors, we cannot afford on a fixed income. The dealership service manager told us that he requested Goodwill from Hyundai Corporate for the combustion engine cleaning. And because of a past denial, corporate denied it a 2nd time. So, we contacted our Hyundai Corporate case manager, who said our request for “the engine replacement” was still pending and in review by their team. She saw no denials, except for a loaner, which would be approved, upon repair approval. We added the dealership service manager on this call to discuss confusion about goodwill be denied by Corporate for the “combustion cleaning”. He said this case manager would not see the combustion cleaning requirement, because it was instructed by another department. His then pivoted the topic & said we received an estimate for combustion cleaning. My response “we never received an estimate & have no estimate in my email”. His response “I hate to use this word, but you’re a liar”. My husband then took the call saying “we did not receive an estimate in writing, although we had asked the tech for an estimate but nothing was final.” The service manager cut him off and said “we are done come pick up your car” & hung up. This dealership phone interaction needed to be included in this incident because now we are being put in grave danger as he is expecting us to pick up our un-drivable, unsafe & hazardous car with no concern for safety.

Filed Oct 7, 2026 · Acceleration, Electrical · VA

While going down the highway at around 72 mph , my car went into limp mode. I was unable to accelerate, the brake and wheel locked. And then the engine light began flashing. The limp mode , non acceleration, and flashing engine light have happened twice before this instance. The first two times the pulled the P1326 knock sensor code and replaced it. Did the update, and sent me on my way saying it was fine. Now this most recent time (the 3rd time), the engine has failed. A CARFAX report says my car already had the engine replaced at 52k miles, meaning there’s 1 something internally wrong and 2 it’s still well within mileage warranty for another engine replacement. This car is extremely dangerous as it can literally stop in the middle of the highway. I went from 72 to about 15 mph in seconds, I was unable to get over or accelerate. It was terrifying. Now dealing with Hyundai - they don’t want to take fault.

Filed Oct 7, 2026 · Engine, Fuel system · NH

The new 2019 Hyundai Tucson equipped with the Nu2.0L GDI engine, I purchased in 1/2020 as the original owner to this day has been diagnosed with a burnt exhaust valve due to heavy oil consumption that has been an uncorrected documented manufacturer’s defect within Hyundai motor corporation. The excessive engine oil consumption has poisoned and destroyed the first catalytic converter, has fouled the combustion chamber which has consequently choked and burnt the exhaust valve with the excess oil ash and carbon buildup. The car was approved for a second catalytic converter install last week which my car currently sits at 125,000 miles and the dealership through the authority of approval with Hyundai motor America has replaced under warranty however subsequently running the excess consumption test, the car now has a burnt exhaust valve which Hyundai motor America is extending a “good faith” proposal which they are willing to replace 60% of the burnt valve and I’m responsible for the 40% even though I have complied fully with the dealership’s recommended preventive maintenance schedule which has been solely performed at the same dealership since the day I bought the car and drove off the lot up until the 100K mile warranty. And now discovering my particular motor has been extended to the 15/150,000 warranty due to the lawsuit settlement. I have continued with my diligence with keeping up with the oil, instead of ignoring the issue that the car burns excessive oil to potentially has the engine fail while driving to be fully covered on the rod bearing failure settlement. Help in my concerns would be greatly appreciated through the federal safety agency.

Filed Oct 4, 2026 · Engine · NC

Unknown believe it engine was replaced due to engine knock

Filed Sep 30, 2026 · Engine · MD

Failed Component: Engine assembly / internal powertrain (specifically, a connecting rod bearing failure in cylinder #2 causing severe engine knocking and risk of mechanical seizure). The vehicle is available for inspection, the complete vehicle and affected engine assembly are intact and available for inspection upon request at CMA's Hyundai of Lexington Park: [XXX] Safety Risk: A rod bearing failure causes violent engine knocking, severe loss of engine power, and eventual engine seizure or stalling while driving. Losing propulsion unexpectedly—especially at highway speeds or in heavy traffic—creates an immediate collision risk for the vehicle occupants and surrounding traffic due to sudden loss of power, power steering, and power brake assistance. The issue was formally diagnosed and confirmed by an authorized Hyundai dealership service department. The technician performed a physical diagnostic evaluation and officially documented a knocking condition resulting from a connecting rod bearing failure in cylinder #2. Symptoms & Timeline: Initial engine knocking noises first appeared on XXX. The vehicle was previously updated with Hyundai's Knock Sensor Detection System (KSDS) Product Improvement Campaign, which is intended to detect excessive vibration from rod bearing wear prior to catastrophic failure. No check engine light illumination occurred or and type of indication from the vehicle there was something wrong other than the knocking noises. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 25, 2026 · Engine · CA

On XXX, while driving at freeway speed in [XXX] with my [XXX] son in the back seat, the engine of my 2020 Hyundai Tucson (2.4L Theta II GDI, approx. 99,108 miles) seized suddenly and without warning. I lost all motive power in moving traffic and coasted to the shoulder, where my son and I sat stranded for 30 minutes with smoke and a burning smell coming from the engine while waiting for a tow. No warning lamps or messages appeared before the failure. COMPONENT FAILED: Engine. Tustin Hyundai ([XXX]) diagnosed the failure on RO XXX: engine seized; connecting rod pierced through the bottom of the engine block due to internal catastrophic failure at the crankshaft/bearings; starter had a burnt smell. The dealer recommends full long block replacement. The vehicle remains at Tustin Hyundai and is available for inspection upon request. CONFIRMED BY: Hyundai dealership technician (diagnosis on RO XXX) and an insurance adjuster (National General/Allstate claim XXX, Estimate of Record on file). A goodwill request was submitted to Hyundai Motor America and denied. RELEVANT DEFECT HISTORY: This is the same connecting rod bearing failure mode for which Hyundai extended a Limited Lifetime Warranty on 2018-2019 Tucson vehicles with the same Theta II 2.4L GDI engine (TSB 22-EM-001H-1/TXXI). Hyundai Service Campaign 9C2 (Theta II ECU software update, issued XXX) was open and incomplete on my VIN at the time of failure and was performed only at the post-failure service visit. Oil consumption without external leaks, a documented characteristic of this engine defect, was present before the failure. SAFETY RISK: Sudden total loss of motive power at highway speed in traffic with a child aboard created a serious risk of collision, and the 30-minute roadside wait exposed us to passing traffic. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 21, 2026 · Engine · MN

I am reporting a suspected safety defect involving my daughter's 2017 Hyundai Tucson, VIN [XXX], with approximately 77,940 miles. The vehicle experienced an engine failure beginning with the illumination of the oil-pressure warning light and Check Engine Light, followed by a pronounced engine knocking noise. The vehicle subsequently could not continue running. The vehicle was inspected by a Hyundai dealership, which diagnosed an engine failure. I am aware of Hyundai Safety Recall 209 / the federal safety agency Recall 21V‑727 involving certain 2017 Hyundai Tucson vehicles equipped with the 2.0-liter Nu GDI engine. Hyundai's recall documentation identifies premature connecting-rod-bearing wear and specifically identifies abnormal engine knocking and illumination of the oil-pressure warning light as symptoms that can precede engine damage and stalling. My daughter's vehicle experienced these same symptoms. Hyundai has informed us that this particular VIN is not included in Recall 209 and Hyundai Motor America has denied our request for assistance. I am therefore asking the federal safety agency to review this complaint as a potential safety defect and determine whether there may be additional 2017 Tucson vehicles outside the current Recall 209 population experiencing the same or substantially similar engine failure. I am not claiming that the vehicle is definitively covered by Recall 209. Rather, I am asking the federal safety agency to investigate whether the exclusion of this vehicle is appropriate given the similarity between the actual failure symptoms and the defect identified in Recall 209. I can provide the dealership's diagnostic documentation, Hyundai Motor America's denial, photographs, maintenance records, and other supporting information upon request. Vehicle: 2017 Hyundai Tucson, VIN: [XXX], Mileage: Approximately 77,940 miles Failure: Engine knocking, oil-pressure warning light, Check Engine Light, engine failure/stalling Related Recall: Hyundai Recall 209 / the federal safety agency 21V‑727. I INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 5

Filed Sep 14, 2026 · Brakes, Engine · 164,000 miles · FL

The contact owns a 2018 Hyundai Tucson. The contact stated that while driving approximately 65 MPH, there was a knocking sound coming from the engine compartment, and the vehicle started shaking aggressively. The brake pedal was depressed; however, the vehicle failed to respond as needed, and the vehicle lost power steering functionality. The vehicle was coasted to the side of the road, and the parking brake was engaged. The vehicle stalled and was towed to the nearest gas station. The vehicle failed to start and was towed to the residence. The failure mileage was approximately 164,000.

Filed Aug 29, 2026 · Engine · NY

OnXXX my car experienced sudden knocking in the engine. I pulled over to the service station on the [XXX] and had my car towed to Empire Hyundai in [XXX]. I had just changed oil on XXXand upon inspection oil level was fine. Problem is the theta 2 engine and though the car is under extended warranty Hyundai is requesting maintenance records before repairing this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)