2017 Hyundai Sonata: sudden loss of power

Filed Jun 30, 2026 · Engine · MD

Driving home from work on [XXX] (not a safe location)when my car lost power and engine light began to flash. I pulled off to the side of road and called my dad. He came with a code reader and said there was a code P1326. He cleared the code and car drove normally again. 2 days later it began to run rough. I was told about the engine recall so I called Hyundai corporate and told them this same story. I was advised to take to dealership and have the “rod bearings inspected” and shouldn’t matter that my dad cleared the code. The dealership(Massey Hyundai MD) said it had a burnt valve and not part of warranty. But never checked rod bearings. When I called corporate. They said nothing they could do. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 31, 2026 · Electrical, Engine · UT

Supplemental Information to Existing the federal safety agency Complaint involving a 2017 Hyundai Sonata Plug-in Hybrid (VIN: [XXX] ) While traveling at approximately 70 MPH on a heavily traveled highway, the vehicle suddenly and completely lost propulsion without warning. The vehicle rapidly decelerated in traffic, creating a significant safety hazard for my family and surrounding motorists and requiring emergency maneuvering to reach the shoulder. The vehicle was towed to an authorized Hyundai dealership, where diagnostic testing identified multiple high-voltage battery system fault codes: • P0B68 • P0B6D • P0B72 The dealership diagnosed a high-voltage battery system failure requiring battery replacement. The vehicle is currently non-drivable. During my research, I found multiple owner reports involving Hyundai Sonata Hybrid and Plug-in Hybrid vehicles experiencing loss of power, hybrid system failures, limp mode conditions, and propulsion-related incidents. I also learned that Hyundai previously issued Recall 18V166000 involving 2016–2018 Sonata Plug-in Hybrid vehicles due to battery management system and voltage protection device concerns that could result in loss of power while driving. Dealer says does appply for my car. Although my vehicle’s fault codes may differ from those addressed in the recall, both involve battery-related failures capable of affecting propulsion and creating a highway safety risk. My concern extends beyond my individual vehicle. A high-voltage battery or battery management system failure that can cause a complete loss of propulsion at highway speed without warning presents a potentially serious safety risk. I respectfully request that the federal safety agency evaluate whether similar incidents involving Hyundai Sonata Hybrid and Plug-in Hybrid vehicles indicate a broader safety concern warranting further review. I can provide dealership diagnostic reports, repair estimates, towing records, photos, and videos upon request. Thank you for your consideration, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATI

Filed May 28, 2026 · Engine · MD

I am writing to report a serious, premature failure of a primary emissions and safety-related component (the catalytic converter) that has occurred as a direct consequence of a known, unaddressed manufacturing defect in Hyundai's Theta II engine. My vehicle has a documented history of excessive engine oil consumption. This inherent manufacturing flaw causes the engine to burn motor oil at an extreme rate, forcing unburned oil directly into the exhaust system. Over time, this oil has fouled and destroyed the catalytic converter substrate, triggering trouble code P0420 and causing a complete component failure. A dealership inspection at Heritage Hyundai Towson (RO #XXX) confirmed "excessive wear" and failure of the catalytic converter. Because the catalytic converter is failing prematurely due to a liquid defect (excessive oil burning) rather than standard wear and tear, it poses an environmental hazard, compromises vehicle emissions control, and can lead to sudden engine stalling or reduced power while driving, presenting an active safety risk. Hyundai Motor America (Case #XXX) has formally denied assistance to rectify this consequential damage, despite full awareness of the underlying engine defect. I request that the federal safety agency investigate how Hyundai’s ongoing oil consumption manufacturing issues are causing cascading safety and emissions component failures in these vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 13, 2026 · Engine · SC

The vehicle experienced repeated engine-related failures associated with the P1326 error code, which indicates a potential engine defect. The issue first occurred around February 2023 at approximately 51,500 miles, when a warning light appeared. The problem has recurred multiple times despite inspections and service attempts. In January 2024, a dealership performed a software update related to the P1326 code. Shortly after this update, the engine began consuming excessive oil (approximately 2 liters per 1,000 miles). The condition worsened over time, and the vehicle failed an oil consumption test conducted by a dealership. The issue was confirmed by an authorized dealership, which ultimately diagnosed the engine as failed and requiring replacement in May 2026 at approximately 99,000 miles. The problem has been reproducible, with the P1326 warning code appearing multiple times over the life of the vehicle. This condition creates a significant safety risk because the engine may lose power, misfire, or stall unexpectedly while driving, increasing the risk of a crash, especially at highway speeds or in traffic. The vehicle has already experienced engine misfire and severe performance issues. Warning indicators included the P1326 error code and check engine light, which first appeared in 2023 and recurred multiple times thereafter. The engine oil consumption issue developed after the 2024 service and continued to worsen. The failed engine is currently available for inspection upon request.

Filed May 7, 2026 · Engine · FL

Engine experienced severe metallic knocking and loss of power. A certified Hyundai technician confirmed a FAILED Bearing Clearance Test (RO #354331). Hyundai Motor America is refusing to honor the Engine II Class Action Settlement warranty, citing internal code A99 because the vehicle was purchased at an auction, even though the title is CLEAN. This pose a safety risk of engine seizure and potential fire.

Filed Apr 30, 2026 · Engine · TX

The failed component is the engine assembly in my 2017 Hyundai Sonata SE with the 2.4L Theta II GDI engine. The failure involves excessive oil consumption and internal engine failure, specifically suspected piston ring deterioration allowing oil to pass into the combustion chambers. The vehicle is available for inspection upon request. Safety was put at risk because the engine was losing oil rapidly. If the oil level drops too low, the engine can seize, stall, or lose power while driving. Sudden engine failure at road or highway speeds could increase the risk of a crash. The issue required constant oil monitoring and made the vehicle unsafe to rely on. The problem was confirmed by both an independent repair shop and a Hyundai dealership. At about 99,813 miles, an independent shop diagnosed oil burning from the tailpipe. I then paid for major repairs, including cylinder head and valve work, but the oil consumption continued. A later independent inspection found internal oil consumption consistent with failed piston rings and oil bypassing into the combustion chambers. The Hyundai dealership performed Hyundai’s oil consumption testing process, including combustion chamber cleaning and rechecking oil level. The vehicle failed and engine replacement was approved. The dealer quoted $11,400-$12,000 for replacement. The vehicle has been inspected by an independent repair facility, a Hyundai dealership, and reviewed by Hyundai Motor America Customer Care under case number 42489659. Hyundai denied assistance, stating the vehicle is outside warranty due to time and mileage. Symptoms first appeared around 99,813 miles and included excessive oil consumption, burning oil from the tailpipe, reduced power/dragging, abnormal rattle/noise during low-speed acceleration, and poor fuel economy. After repairs, the oil level still dropped below minimum quickly. I am filing this complaint because this condition may cause sudden engine damage, stalling, or loss of power while driving.

Filed Feb 14, 2026 · Steering · CA

While driving around 45 mph, the steering wheel locked up and car came to a hard stop. Luckily cars swerved to avoid me. This was the second time it happened. The first time I was in a parking garage and the steering wheel locked up. After restarting the vehicle, the steering wheel worked again. The dash showed no fault codes or engine light. I found out there is a service bulletin and took it in to the dealer. Once there, the confirmed it was the power steering and is covered by the service bulletin and extended warranty. However, because the bulletin requires the dealer to clear code to try and reproduce it, I have to pick up vehicle because they could not reproduce the fault code. So now I have to drive the vehicle knowing their is a service bulletin for the problem and have it happen again before it is fixed. There is an extremely high likelihood of injury considering you lose all power at wheel and car continues to move.

Filed Feb 8, 2026 · Engine · FL

My 2017 Hyundai Sonata Hybrid has a permanent and recurring DTC P1326 (Knock signal range/performance) from the Knock Sensor Detection System (KSDS), indicating potential connecting rod bearing wear in the Nu 2.0L engine. The vehicle enters limp mode (reduced power, limited acceleration/speed) on the highway under load, with hard engine vibration, tinkling/knocking noise from under hood, and significantly reduced MPG. These symptoms create a serious safety risk: sudden loss of power at highway speeds (e.g., 50+ mph) makes it difficult to maintain speed, merge, or avoid hazards, increasing crash risk or stranding in traffic. In rare cases, bearing wear can lead to engine seizure or failure. The problem first appeared summer 2024 at approximately 115,000 miles. The Check Engine Light illuminates (cristmass tree), and limp mode triggers during highway driving. I have an OBD scan showing confirmed, pending, and permanent P1326, plus related hybrid communication codes (U0293, U1004) likely secondary to the protection mode. The vehicle has been inspected multiple times (four visits) by a Hyundai dealer. Each time they scanned the code, performed basic checks, but stated “engine is working normal, no road vibration, nothing” and did not resolve the issue. The code returns immediately after clearing. I replaced the knock sensor, engine mounts, spark plugs, ignition coils myself—did not fix it. Dealers did not perform the full bearing clearance test or follow TSB 22-01-023H (Service Campaign T6G) procedure as required for this known issue (related to Recall 209 and Campaign 966). The component (engine/connecting rod bearings) is still in the vehicle and available for inspection. No police, insurance, or other parties have inspected it beyond the dealer. This matches a widespread known defect in 2011–2019 Sonata Hybrids (bearing wear triggering P1326/limp mode).

Filed Nov 29, 2025 · Electrical, Engine · TX

e vehicle is burning approximately 2 quarts of oil every month with no external leaks. This indicates severe internal oil consumption, which is a known defect in Hyundai’s Theta II 2.4 GDI engines. I discovered oil inside the VVT solenoid electrical connector and on other wiring, which shows oil is traveling through the engine harness. This causes hesitation, rough running, and the risk of sudden engine power loss. The vehicle feels unsafe to drive because the oil level drops quickly, and the engine could seize or stall while driving. Hyundai vehicles of this generation have a history of excessive oil consumption, piston ring failures, and engine fires, and I believe my vehicle is experiencing the same defect. This is a serious safety concern.

Filed Nov 10, 2025 · Steering · FL

While driving my vehicle I have lost power steering twice completely. The first time I was in a five-story parking garage turning into a parking space, when power steering went out. The second time I was pulling into my driveway and the power steering went completely out. At other times my car would pull to the right just a little at one point or maybe even harder at other points. I never know when I'm going to have a problem sometimes I don't have a problem, car drives normal this problem has existed for the last 3 weeks. Like power steering sometimes is harder to turn to the left around a curve are a corner. When the steering goes out warning lights do come on one like a hazard sign one like engine light and others. I take really good care of my car my personal mechanic has called Hyundai so he could get information on how to fix my vehicle they have informed him that I have to bring it into them and would not tell my mechanic what the problem was. I would say the problem exists 20% of the time 80% of the time the card drives great no problems but while driving these things change.

Filed Oct 5, 2025 · Engine · MA

Purchased the vehicle and immediately noticed a drip in the driveway. I was concerned so I started checking the dip stick. I booked a diagnostic appointment with a Hyundai Service Center. I wanted to be sure I purchased a quality vehicle. Upon what i thought was a complete diagnostic, a cracked oil pan was discovered. I agreed to purchase and pay out of pocket, everything else had checked out. I was told I could drive while I waited for the pan to come in, service was scheduled. The car never made it back. I continued to check the dipstick but while driving on a very busy interstate, the engine light went on and lost power. I barely managed to get to the breakdown lane. A complete safety hazard. I was towed to the closest garage where the owner suggested he see’s 3-4 of these a week. He would not touch it, have it towed to Hyundai. I paid for another diagnostic and now a flat bed tow. Key Hyundai of Salem NH accepted the vehicle. I paid another $498 to have an “engine tear-down” send a detailed finding report to Corporate. I called Corporate and filled my own case number. I was denied by Corporate, I was told I was a subsequent owner. The dealership didn’t match, I’m denied because the engine didn’t seize because of Rod issue. Well Hyundai is praying upon consumers. They knowingly initiated the KDS Recall and installed sensors to place a vehicle in “Limp Mode” so the rod isn’t the issue and they deny coverage. I paid a private mechanic verify cylinder 3 has low compression. Had the car not gone into “Limp Mode” the rod bearings would have failed.

Filed Sep 18, 2025 · Engine · VA

My 2017 Hyundai Sonata SE is experiencing symptoms consistent with connecting rod bearing failure covered under Hyundai’s KSDS extended warranty program. June 22, 2019: KSDS software (Campaign 953) installed, qualifying the vehicle for Hyundai’s 15-year/150,000-mile warranty coverage for bearing failures. August 2022: Campaign 208 engine recall performed. Hyundai’s record shows Aug 15, 2022, while Wright Way Hyundai’s service history shows Aug 13, 2022 (discrepancy unresolved). March 2025 (100,238 miles): Vehicle went into limp mode with tailpipe smoke and loss of power. It was towed to Wright Way Hyundai, which kept it for several days but returned it with “no issue found.” The smoke continued. June 5, 2025 (103,996 miles): Oil change performed. August 27, 2025: Oil light illuminated, dipstick showed no oil. Vehicle now exhibits severe drivability issues consistent with bearing damage. Hyundai has incorrectly tried to reframe this as an oil-consumption issue and directed me to pay $600 for a combustion chamber cleaning. My issue is not oil consumption — it is a bearing-related failure already covered by warranty. Hyundai’s obligations include a no-cost inspection/diagnosis for connecting rod bearing failure, yet I have been denied that process. Despite repeated written requests, Hyundai continues to attempt phone communication instead of email, even addressing me by the wrong name in correspondence, which suggests reliance on standardized or generic responses. I have exclusively maintained the vehicle at Wright Way Hyundai, following Hyundai’s service schedule. I am resorting to filing this complaint because after weeks of email correspondence, Hyundai’s corporate agent refuses to help and the manager insists on only calling by phone — which I will not answer out of concern they will attempt to mischaracterize or dismiss my complaint verbally. This failure poses a safety risk because the vehicle has lost power suddenly and requiring restart.