2016 Hyundai Sonata

The contact owns a 2016 Hyundai Sonata. The contact stated that while getting an oil change, the contact was informed that the oil pan was empty. The contact could not recall seeing leaks or making changes to the oil change routine. An independent mechanic informed the contact of an engine recall regarding excessive oil consumption. The contact was referred to the dealer. The contact had the oil inspected twice more and was informed of low oil levels on each occasion, but there were no leaks or burning oil odors. The vehicle was taken to the dealer, where it was confirmed that no open recall was associated with the VIN. The dealer replaced several sensors; however, the contact was unable to specify which sensors were replaced. The dealer stated that the vehicle needed to be driven until the next oil service, at which point the oil would be changed and the engine sealed. The contact was referred to the NHTSA hotline to file a safety complaint. The manufacturer was notified of the issue, and a case was escalated. The failure mileage was approximately 70,000.

The contact owns a 2016 Hyundai Sonata. While the contact's daughter was driving 55 MPH, the engine seized. The contact stated that the failure had occurred while the contact's two minor grandchildren were inside the vehicle during the failure. The vehicle was towed to an independent mechanic. The vehicle was later towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The manufacturer was contacted, and a case was filed. The contact was informed about the eligibility for the extended warranty under Campaign 953. The contact was informed that the repair was not covered under the extended warranty because the Campaign 953 was not completed. The failure mileage was approximately 60,436.

While driving on the freeway, the check engine light started flashing and the gas pedal became useless. This put the driver and the passenger of the car in massive danger as they could no longer accelerate on the freeway. Luckily, they were able to get off the freeway without causing an accident. Upon reading the code at an auto shop, they discovered that it was P1326 or a knock sensor issue. This malfunction caused the car to go into limp mode and put the passengers in serious danger. Several calls to the Hyundai Service Center were made yesterday (Saturday, October 3rd). However, not one was ever answered. They hope to be able to get the car to the dealership's service center as soon as possible, but the earliest appointment online is multiple weeks away. This same car was recently at the dealership service center for an internal engine oil consumption problem and thoroughly inspected. The car is up to date on all software and recalls. Even though a valve cover replacement fixed the oil consumption issue, the owners are now having even worse issues. This is the only car for a married couple who are both working and going to college full-time. This issue has been a severe complication to their scheduling, and they were put in harm's way on the freeway.

Backup vision system failed. Couldn't see vision because screen was blank. Radio didn't work either. Went to dealership with the problem they said it was not covered by the warranty. Paid to have it fixed.

The vehicle experienced a Theta II engine failure at under 57,830 miles while driving on northbound [XXX] near the [XXX] Parkway U-turn in [XXX]. The engine made a loud noise and lost power. I was able to coast to the far right side of the U-turn under the bridge. I called HERO (Austin's emergency roadside assistance). They responded, determined it was not a battery issue, and pushed the vehicle to the Southern Leisure Spa parking lot on the southbound side of the road. The vehicle was then towed. The vehicle is equipped with the KSDS (Knock Sensor Detection System) software update, installed as part of Hyundai's remedy for this known defect. Despite KSDS being installed, the engine failed due to connecting rod bearing wear, consistent with the documented Theta II defect. A Hyundai dealership confirmed KSDS was installed but denied the warranty claim, citing maintenance records. The vehicle is available for inspection upon request. The Theta II engine defect has been the subject of prior NHTSA investigations and Hyundai recalls. This complaint is filed to document another failure of the same defect in a vehicle with the manufacturer's remedy installed. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I am concerned that the engine may seize or stall without warning while driving, creating a risk of crash, injury, or death. The Theta II engine defect is known to cause engine seizure, stalling, and fire. Hyundai has denied warranty coverage based on mileage and second-owner status — both of which are explicitly prohibited as denial grounds under the Settlement — leaving me driving an unsafe vehicle.

The car died while going 70 on a highway with no warning signs. The car completely shut off and will not turn over or move at all.

Component & Inspection: Vehicle engine suffered connecting rod bearing failure and entered restricted P1326 "Limp Home Mode" (max 2,000 RPM). The vehicle is grounded and available for inspection at Bud Clary Hyundai in [XXX].Safety Risk: Sudden, unexpected loss of power occurred while driving, placing me and other drivers at immediate risk on public roads due to the vehicle's inability to maintain normal traffic speed or safely accelerate.Dealer & Corporate Confirmation: Active P1326 engine code is confirmed. Car has been held for 14 days. The franchise is violating federal settlement rules by explicitly refusing to execute the mandatory, free mechanical Bearing Clearance Test (BCT) unless I pay out-of-pocket fees.Inspection & Corporate Compliance Failure: Car was brought to the dealer on XXX. The service manager admitted in writing that they are withholding safety diagnostics to protect shop labor hours due to an automated computer flag regarding a clerical title brand discrepancy. Hyundai Corporate is actively enabling this violation; my case manager refuses to issue a manual compliance override for the safety test and is violating federal settlement terms by withholding my contractually mandated alternative transportation.Warning Lamps & Symptoms: Flashing Check Engine Light and limp home mode triggered instantly and unexpectedly on XXX. There were zero warning symptoms, messages, or abnormal noises prior to that date INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My Sonata 2016 suddenly lit up the Check Engine icon, which was blinking. It is available for inspection request, as it's in the shop right now. Added 2 qts of oil just to be safe. Was hoping the light would go away in the morning. It didn't. The car was sputtering and jerking while I was attempting to get where I was going, so I drove a little slower so it wouldn't stall out, which would have caused someone behind me to crash into me if it stopped suddenly. My mechanic said it was engine failure, possibly due to oil burning. Hyundai Dealer told me there is no recall for this issue, but my mechanic said there had been. I was never notified of such, and when I called them, they said that there was no recall, and she acted like she had never heard of the problem. I find that amazing, since on your website, there are some 717 claims of the same problem.

My 2016 Hyundai Sonata (VIN: [XXX]) has a serious safety issue involving excessive engine oil consumption. The vehicle loses oil rapidly between changes and requires frequent top‑offs to avoid engine damage. This creates a risk of sudden engine failure while driving. The dealership, South Charlotte Hyundai (10518 Cadillac Street, Pineville, NC 28134), refused to perform Hyundai’s official oil‑consumption test. Instead, they told me to pay $750 for a combustion cleaning and stated it would not fix the underlying problem. They would not document the refusal or provide any testing. I contacted Hyundai Corporate multiple times: • May 21, 2026 – Executive Office complaint submitted • June 3, 2026 – Follow‑up sent • June 29, 2026 – Regional escalation sent My Hyundai case number is XXX. As of XXX Hyundai has not responded to any of my Executive Office or Regional escalations. Only Customer Care replied with a template denial and no investigation. I have been waiting over two months with no action from Hyundai Corporate. I am reporting this because the manufacturer has not addressed a safety‑related defect, the dealership refused required testing, and the vehicle continues to consume oil abnormally. I am requesting NHTSA’s assistance in documenting this defect and Hyundai’s lack of response. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Cylinder 3 misfire code and rough idle/driving car tries to stall out, engine is consuming a quart of oil every 500 miles and has 30psi compression in cylinder 3. Car only has 129k miles

My 2016 Hyundai Sonata 2.4L suffered an in-transit engine failure and entered emergency limp mode with an active P1326 rod bearing defect code, which is a recognized fire and safety hazard under NHTSA mandates. Service Campaign 953 was successfully completed on August 12, 2019, qualifying the vehicle for a lifetime settlement engine replacement. Walser Hyundai Brooklyn Park (RO #257457) has issued an administrative denial based solely on a prior-salvage title flag from a cosmetic theft recovery. The manufacturer is actively stalling a court-ordered federal safety recall remedy based on an administrative title brand, despite the engine compartment being structurally original and undamaged. Hyundai Corporate Case #42869828 is open but unresolved.

The contact owns a 2016 Hyundai Sonata. The contact stated that while driving approximately 60 MPH, the vehicle suddenly shut off with the message "HEV System Failure" displayed. The driver safely pulled over to the side of the road and restarted the vehicle. A towing truck arrived on the scene and reset the diagnostic codes before towing the vehicle. The vehicle was towed to the local dealer. The dealer retrieved several diagnostic trouble codes; however, the dealer was unable to determine the cause of the failure. The vehicle was test-driven but the failure was not duplicated. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 149,000.

After the emissions 9c2 recall car hesitant when changing an Hyundai has knowledgement of the problem but don’t have a fix

I was driving at night and my passenger headlights went out. About 2 years prior the same thing happened but it was the driver side headlight that went out. It was $1100 to get the driver side replaced and now here i am having to pay the same amount to replace the passenger side headlights. It was not a simple replacing the bulb. Something inside went broke causing the dealership to have to install a whole new headlight set.

Went from 65 and dropped down to 40 going up grades on the freeway. Started shaking, check engine light went on and electric battery disappeared from dash. Got to top of grade, went back to normal. Problem repeated on next grades. Car had just left dealership lot an hour prior where it was safety inspected and they said all was fine. Took back to dealership for inspection and they said that there were no codes showing for what happened and all was well with the vehicle, when obviously it was not.

The following mandatory software update was performed on my vehicle: ECU SOFTWARE UPDATE FOR THETA II EMISSIONS IMPROVEMENT (SERVICE CAMPAIGN 9C2). After this update my vehicle drivetrain is quite erratic. In particular when the engine is cold it appears to jerk even when in Parking gear position. When cold the drivetrain experiences erratic gear shifts. This provides little confidence when driving and could result in safety issues when merging into traffic. Once the engine has reached its normal operating temperature it still makes occasional gear shift that are jerky and probably not good for the transmission. This vehicle had a very smooth transmission prior to the ECU software update, now I am hesitant when I need to merge into traffic, since I am not sure it will select the correct gear when accelerating. I have reported this to the dealership and Hyundai corporate service center and both indicate that when the engine is cold that the drivetrain can act strange, but once it is up to temperature it should be smooth. I have looked on the web and noticed multiple Hyundai owners with similar engines reporting the same issue after this software update. Hyundai may have satisfied the EPA requirements with this software, but they may have a created a safety issue for the vehicle operator and their passengers.

Car just stated making g noise went into lp.mode now saying k ock sensor

After completion of Hyundai Service Campaign 9C2, my 2016 Hyundai Sonata SE is very difficult to drive at low RPMs. Cold start its sluggish and jerks and driving uphill feels like transmission slipping but is not. An additional update to the ECM needs to be conducted ASAP.

My 2016 Hyundai Sonata is experiencing severe oil consumption due to a known Hyundai engine defect. The engine burns oil rapidly and loses more than a quart between oil changes. This creates a safety hazard because the engine can stall, seize, or fail while driving. The Hyundai dealership did NOT perform the official Hyundai oil-consumption test. They only checked the dipstick, noted the oil was low, and submitted a request for a paid combustion cleaning. Hyundai declined to pay for the cleaning, and the dealership is refusing to perform the required oil-consumption test unless I pay $750.00. Hyundai Corporate also refused to authorize the test, stating the vehicle is out of warranty, even though this is a known engine defect affecting many Hyundai vehicles. Without the official test, Hyundai will not review the engine defect or consider a goodwill engine replacement. This is a safety issue because the engine can fail without warning. The dealership and Hyundai are refusing to perform the required diagnostic test unless I pay $750, and refusing to review the defect without that test.