What 748 owners told NHTSA about the 2016 Kia Optima

Engine sludge and failure. Engine part failure p0010 began happening within 1 year of Kia engine replacement. It is available for inspection. This creates a problem with acceleration in the vehicle, putting my family's and my safety at risk. This problem has been confirmed by the dealer. The check engine light is one. This part failure and engine sludge (despite consistent maintenance) has caused engine failure again, just 3 years after replacement.

NHTSA ODI 11691181

All window regulators failed before 100K miles. This does not allow for windows to open in case of emergency, This problem has been personally confirmed by dealer and also in service bulletin SA418. This is a common problem in this car make/model/year. This component has been known to the manufacturer for defect. No warning lights, just instant lack of window use.

NHTSA ODI 11691183

I have a 2016 KIA Optima SX Turbo with 33,500 miles that the windows one by one are failing due to a defective regulator drum gear. This very flimsy gear fails and the window will not roll up. I have had 3 out of 4 fail in the last month. The only way to keep the window up is to shimmy them. This creates a huge safety risk in the event of an accident and also can impact the collision safety system including airbags. KIA is aware of this situation as outlined in their Technical Service Bulletin dated March 2021. I believe it's bulletin MC-10189544-0011. I've contacted the dealer who doesn't think there is a recall on this issue. This issue creates a safety issue that after only 33,500 miles should not exist.

NHTSA ODI 11690314

The car is burning oil rapidly causing potential issues with the transmission and engine. The oil burns and does not leak after a few hundred miles and has to be refilled continuously causing alot of money and potential issues with other components of the car. I notice jerking when accelerating and smoke if dont fill every 1 to 2 weeks.

NHTSA ODI 11689950

In 2024 the window regulator went in the drivers side back window costing me $700 and on 9/22/2025 the drivers side front window regulator just went costing me another $700. I see many are having this issue but no recall

NHTSA ODI 11689112

Window regulator assembly failed twice within 20k miles. Attached is the first repair. Dealership only repaired motor but not full assembly and it failed again.

NHTSA ODI 11684762

The headlights and brake lights have been VERY dim for a while. I've had to replace both headlights and brake lights an excessive amount in the last several years. This year alone since December 2024, I've had to replace my headlights 3 separate times. I do not drive more than 10,000 miles per year, or use my vehicle on roads that would lead me to believe the issue is from road conditions.

NHTSA ODI 11684788

Engine Is knocking that happened when I took my car 3 times to emission test and my car didn't pass after that I took it to my mechanic for the diagnostic and he told me you have to take it to kia dealer but I was shocked the way how they treated me and they completely refuse to replace my engine they came up with too many excuses and I have recall repair active I have right to fix my car but they didn't with bad attitude

NHTSA ODI 11682663

Engine began jumping during driving and loss power. No dashboard illumination warning lights and the temperature gage showed normal operating temperature. Car was not accelerating properly. Had to maneuver carefully to prevent being ran over. Engine light illuminated showing misfire. Replaced ignition coil pack and spark plugs. Driving again, car stalled. No dashboard warning lights. No high temperature on gauge. Narrowly missed being hit by a semi as there was absolutely no warning and we were on an Interstate bypass ramp with nowhere to pull over!! Towed car to dealership for diagnosis. Results: engine blown, turbos gone, and the catalytic converter is holding oil. Dealer is stating this is not covered under the extended warranty from Kia as its not connector rod bearing issues and that the piston rings failed. However, they stated the turbos got "too hot" and they failed. The gauges have never shown that the car was running hot. I have a sworn statement from my mechanic stating this is absurd and a valiant attempt to not pay for what would be the second warranty replacement of my engine. The piston rings failed as a result of the connector rod bearing failure. The "too hot" temperature that damaged the turbos was likely caused by the same bearing issue. The heat from the bearings unseated the piston rings and allowed the engine to dump its oil causing the engine to fail. I highly recommend that you open an investigation into these issues. The car not accelerating and losing power at interstate speeds is a very serious and dangerous issue.

NHTSA ODI 11682517

The contact owns a 2016 Kia Optima. The contact stated that while driving approximately 75 MPH and attempting to accelerate to overtake a semi-truck, the vehicle suddenly started losing automotive power and then stalled. The vehicle was towed to the local dealer, who diagnosed that the engine had seized and needed to be replaced. The vehicle was not yet repaired. The contact indicated that prior to the failure, the check engine warning light illuminated and remained illuminated, and the engine experienced excessive oil consumption. The manufacturer was not yet notified of the failure. The failure mileage was 45,000. The VIN was not available.

NHTSA ODI 11682043

Dashboard shows a crack right where the passenger airbag is and Kia Motors wont change it, also the paint is flaking and noticed other Kia models with that same paint scheme that’s peeling off.

NHTSA ODI 11682167

I am filing this complaint to urgently bring attention to a serious safety and mechanical defect with my Kia vehicle's engine and fuel system. My engine is excessively consuming oil, to the point where it poses a significant risk of engine failure, which could result in a loss of power while driving and create a hazardous situation on the road. Details: I consistently have to add 5 quarts of oil approximately every month. During regular oil changes, there is barely any oil recovered from the engine, suggesting the oil is being consumed or burned internally. I took the vehicle to AutoZone for diagnostics, and they confirmed the engine is burning oil. They also mentioned it could be related to a rod or piston ring issue. There are no visible leaks under the vehicle, and the oil is not being expelled externally—it's being consumed by the engine. This issue is not normal wear and tear. It's a systemic engine defect that is causing rapid oil loss and is likely to lead to engine seizure or failure if not addressed. This level of oil consumption is not just expensive—it is dangerous. A sudden loss of engine power could cause an accident, especially at highway speeds. I am deeply concerned for my safety and the safety of others on the road. Urgency: I am requesting the NHTSA to investigate this issue and consider initiating a recall for affected Kia vehicles. I am not the only one facing this problem—online forums and consumer reports are filled with similar complaints from other Kia owners. This is a critical engine/fuel system safety defect that must be addressed immediately before someone is injured or worse due to engine failure while driving. Thank you for your time and attention to this matter. I am available to provide service records, photos, and further documentation upon request. Sincerely, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11681325

The engine is starting to fail causing issues such as being able to accelerate. When driving on the freeway it caused a safety issue it began slowing down on the interstate. The vehicle has been inspected by mechanics. No warnings prior to problem. They appeared day before due for an oil change. The car also burns oil really fast sometimes causing car to smoke. I have a GDI turbo engine and have been told that the engine i have has been recalled a few times on different models cars.

NHTSA ODI 11680441

My 2016 Kia Optima EX (VIN [XXX] , 2.4L I4 DI) suffered sudden engine bearing failure and complete engine seizure after approximately three months of use. After inspection, the Kia Scottsdale dealership confirmed that my vehicle’s VIN was eligible under the engine replacement warranty and submitted a request for assistance.However, Kia America denied the request. This defect is identical in nature to the known dangerous defect covered under Kia Safety Recall SC147 (NHTSA 17V-224) and related recalls for earlier Optima model years, involving connecting rod bearing wear leading to engine seizure. In my case, the defect caused a total loss of motive power, posing a serious crash risk. Kia Motors America has refused to repair or replace the engine, claiming my vehicle is ineligible due to being purchased from an auto auction (Sierra Auction) and having multiple prior owners. This refusal ignores that the defect is a safety-related manufacturing flaw identical to those already acknowledged by Kia and subject to federal recalls. I request NHTSA investigate Kia’s refusal to extend the same safety remedies to my VIN and consider whether the scope of SC147 and related recalls should be expanded to include vehicles with the same defect pattern. Supporting documentation available upon request. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11679734

The contact owns a 2016 Kia Optima. The contact stated that while driving at 45 MPH, there was a misfire coming from the engine, and the vehicle was shaking. There was no warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The vehicle was diagnosed with engine failure due to piston rings failure, causing coolant intrusion into the engine. The contact was informed that the engine needed to be replaced. The contact stated that the ignition coil, cylinder #1, and spark plugs were replaced. The dealer was contacted, but had not diagnosed or repaired the vehicle. The manufacturer was not made aware of the failure. The failure mileage was approximately 100,000.

NHTSA ODI 11679889

I have pictures

NHTSA ODI 11678323

No FireNo Injuries0 Deaths0 I’m experiencing severe oil consumption and spark plug fouling, which are known problems with the GDI engine. This is affecting driveability and may indicate piston ring or valve seal failure. My engine code starts with G4KJ which falls under the current recall, but my vin does not show up. Why isn't my car eligible? I have called Kia and their response was to call my local dealership. Started noticing the issue on [XXX]. Called dealership at that time and they said my car doesn't qualify. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11676566

While driving at approximately 45/50 mph, the right rear window suddenly dropped into the door panel without warning. This unexpected failure startled me and created a distraction while driving, as well as compromised my ability to hear and concentrate safely. My left rear window has also slipped into the door panel and is now being held up by shims and I have now discovered that the issue is due to a failed window regulator. This is a known issue in similar vehicles and poses a potential safety hazard, especially during adverse weather or high-speed driving. The Manufacturer has not issued a recall only a bulletin and the cost that was quoted to me from Hendrick Kia of Concord was over $900 dollars a regulator.

NHTSA ODI 11676220

Complaint Message – 2016 Kia Optima Engine Failure Without Oil Light Warning I am the owner of a 2016 Kia Optima (VIN: [XXX] ). My vehicle suffered complete engine failure due to oil starvation — without any prior oil warning light or indication. The engine died while driving, and it was only afterward that I discovered the engine oil was extremely low. The oil pressure light never illuminated at any point to warn me. I am aware that Kia previously recalled earlier model years (2011–2014) for similar engine issues under Recall SC147 and others, related to the Theta II engine and oil pressure-related failures. Many owners reported the exact same symptom — catastrophic engine failure without oil light warnings — that I am now experiencing in my 2016 Optima. Although my model year is not included in the existing recall, the failure pattern appears identical. I believe this presents a significant safety issue that should be investigated. A critical warning system (oil pressure light) failed to function properly, which directly led to engine damage. I am requesting that this issue be reviewed and investigated by NHTSA and Kia for potential expansion of the recall or warranty coverage to include the 2016 Optima. I have already contacted Kia and am pursuing further review through the dealership and customer support. Please note that other 2016 Optima owners have reported similar complaints online and in forums, and this issue may affect a broader number of vehicles than currently acknowledged. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11675639

I’m experiencing severe oil consumption and spark plug fouling, which are known problems with the GDI engine. This is affecting driveability and may indicate piston ring or valve seal failure.

NHTSA ODI 11675447

Odometer Fraud. The contact purchased a 2016 Kia Optima. The contact stated that while attempting to register the vehicle, it was discovered that there was a mileage discrepancy. The vehicle was a dealer sale. At the time of purchase, the vehicle mileage was 56,276. and at the time of registration, it was discovered that the mileage was 114,000.

NHTSA ODI 11675005

Engine issue, it’s knocking loud and misfires. Engine light flashing and Car went into limp mode , will not go over 60 mph . I have changed the spark plugs, knock sensor, and had an oil change nothing has fixed my issue.

NHTSA ODI 11674420

1) Rear passenger window failed a couple months ago. I believe it was regulator, not 100% sure. Cost me a couple hundred to fix. Now, few months later, the driver side rear window has failed. I rarely use the windows so I believe the failing parts are Kia known manufacturing defect. The dealer acknowledged that it’s a known problem with the vehicles like mine and even suggested the other one is going to fail soon. Now it has. If the dealership is aware then it’s likely a Kia flaw. If it’s a know manufacturing flaw, shouldn’t Kia should be fixing them instead of making customers spend upwards of $1k+ to fix both windows? 2) cruise control cuts off or doesn’t set and menus won’t go back to speedometer. While trying to set cruise control, it gets into the menu and won’t go back to the speedometer. Sometimes I have to pull over and stop to get the cruise control to work again. It gets stuck in the menu and can’t see the speedometer. Might get stuck on the trip screen, or the range. This has been happening since about 75k miles. It also doesn’t work with the pedal to set sometimes. Messing with it while driving can be a real hazard and sometimes I need to have cruise control to work. It’s deforming more than just inconvenient

NHTSA ODI 11673169

I own a 2016 Kia Optima EX with VIN [XXX] . The engine failed at 85,763 miles due to a rod bearing seizure. This matches the known defect in Kia’s 2.4L GDI engines, which has been the subject of recalls and service campaigns in the past. Despite being covered under Kia’s extended engine warranty, Kia America denied my engine replacement claim. They cited "vehicle reconditioning" and "multiple ownership" as reasons — neither of which are valid grounds to void warranty coverage, especially for a known defect. A certified Kia dealership (Mark Kia in Scottsdale, AZ) approved my vehicle for warranty replacement, and submitted the request. Kia corporate denied it. This creates a serious safety concern and shows that Kia may be wrongfully avoiding responsibility for this defect. Please investigate. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11672313

Several safety-critical systems failed on this vehicle. The engine (Theta II 2.4L GDI) failed due to rod bearing wear, causing sudden power loss on the highway. The vehicle entered limp mode, once at 50 mph in 2018 and again at 70 mph in 2025, and had to be pulled over quickly to avoid collision. Additional issues: all four windows failed at different times, leaving them stuck open and creating safety risks in weather or emergencies. The trunk latch failed, causing unsecured cargo risk. ABS, TPMS, and traction control warning lights illuminated repeatedly, indicating possible loss of critical safety systems. A loose wiring harness caused the turn signal bulb to burn out repeatedly, reducing visibility and signaling. The dealership performed the KSDS software update after I reported engine trouble but did not resolve the issue. The engine soon failed completely while driving. Other issues, such as the fuse box blowing fuses from a standard USB charger have also been documented by a Kia dealership but not always fully repaired. The most recent engine failure and electrical defects are being inspected by a Kia dealership, and Kia Consumer Affairs is reviewing the warranty claim. Prior to the engine failure, I smelled burning oil and topped it off monthly due to excessive consumption. The oil level light and check engine light only appeared during limp mode right before the failure. These repeated safety-critical defects, particularly sudden engine failure at highway speed, created a significant safety hazard for myself and others on the road. At the time of this report, I am in the process of seeking warranty coverage for the catastrophic engine failure through Kia. The failure behavior (limp mode, flashing check engine light, and rod knock) is consistent with the safety defect described in the Theta II engine settlement. I am concerned that despite this being a known issue, there may be delays or denials in honoring the safety-related warranty repair.

NHTSA ODI 11672345