What 748 owners told NHTSA about the 2016 Kia Optima

Engine brocked the pistones brock stock engine and pay for new engine

NHTSA ODI 11707061

The contact owns a 2016 Kia Optima. The contact stated that while driving approximately 40 MPH, a knocking sound coming from the engine compartment was heard, and the check engine warning light illuminated. The contact further stated that while driving at approximately 80 MPH, with the cruise control mode engaged, the vehicle started to stall and failed to exceed 30 MPH. The contact stated that the cruise control became inoperable, and the check engine warning was flashing. The vehicle was restarted; however, the vehicle continued to hesitate and failed to exceed 30 MPH while driving. The dealer was contacted, but the vehicle was not diagnosed or repaired. The contact was referred to the NHTSA hotline for further assistance. The manufacturer was not made aware of the failure. The approximate failure mileage was 70,000.

NHTSA ODI 11705384

My 2016 Kia Optima is experiencing severe internal engine oil consumption that matches known issues Kia has recalled and extended warranties for. The vehicle loses 1–3 quarts of oil every few days with no external leaks. A repair shop found a P0304 cylinder 4 misfire, P0010 cam actuator code, and spark plug damage caused by oil entering the combustion chamber. They confirmed internal engine damage and abnormal oil consumption. The Kia dealership refused to assist due to mileage, even though this issue matches the engine defects covered under Kia’s litigation settlement and warranty extensions. The excessive oil consumption creates a dangerous safety risk, including engine stalling, loss of power, and potential engine seizure while driving. I am requesting NHTSA review because the vehicle’s condition is unsafe and part of a widespread engine defect.

NHTSA ODI 11704086

The engine lost cylinder 3, piston came loose and broke the spark plug. This happened because the rod bearing came loose which has been a known issue with Kia. There’s already been a class action law suit, and recall with warranty. Now the Kia dealership in Lynchburg has refused to honor this warranty. Stating they can’t do the required rod bearing clearance test because the engine doesn’t have compression. The engine has no compression because the rod bearings came loose and shoved the piston into the head.

NHTSA ODI 11702141

While driving, the vehicle suddenly developed a loud knocking noise from the engine. Within one block the vehicle began smoking heavily from under the hood. I pulled over, opened the hood, and flames were visible. This is a 2016 Kia Optima with the 2.4L Theta II engine. Approximately one year ago the original engine seized and was replaced by a Kia dealer under the Theta II engine recall (SC172/SC147) and class-action settlement. This is the second catastrophic failure of a Theta II engine in this vehicle. The replacement engine has now failed in the exact same manner as the thousands of other documented cases — rod bearing failure leading to knocking, overheating, and engine compartment fire. The dealership (Fowler Kia of Windsor, CO) inspected the vehicle and quoted over $6,000 in repairs (melted engine wiring harness, ECM connector, battery cables, airbox, intake boot, etc.) while claiming the fire was “unknown cause/not the engine,” despite the clear knocking immediately preceding the fire. Kia Consumer Affairs has an open case but has not yet resolved coverage. This is a known, ongoing safety defect covered under multiple NHTSA investigations (PE21004, EA22002) and Kia recalls. I no longer feel safe in this vehicle and am requesting immediate investigation and inclusion in any expanded recall or remedy.

NHTSA ODI 11700454

Vehicle: 2016 Kia Optima LX Turbo – Approx. 114,155 miles** This complaint concerns ongoing systemic defects affecting the electrical, braking, and engine management systems of the referenced vehicle. Despite multiple documented repair attempts, the failures persist, creating continuous and significant safety hazards. The vehicle has experienced repeated electrical system malfunctions, including multiple battery failures (three replacements within one year), sustained low-voltage conditions, and intermittent lighting loss. Notably, the headlights and exterior lighting have shut off unexpectedly during extended highway operation. The brake control system is also compromised. The electronic emergency brake has engaged spontaneously while the vehicle was in motion, causing abrupt deceleration without driver input. Additionally, the vehicle exhibits continuous fuel vapor and engine performance defects. The purge valve has been replaced four times, yet the failure recurs. The vehicle frequently hesitates upon acceleration, exhibits delayed throttle response, and jerks during takeoff, creating hazardous conditions when merging into traffic or crossing intersections. Given the repeated nature of these defects and the lack of resolution through standard repairs, I believe the vehicle may contain inherent design or manufacturing defects affecting the electrical charging system, ECU, fuel vapor management components, and electronic braking controls. I request that NHTSA conduct an investigation into these safety-related defects.

NHTSA ODI 11699731

My engine blew up and started smoking while driving

NHTSA ODI 11698745

Car stop accelerating when I went to get my oil change the shop reported my engine eating up my oil found out kia have a recall on engine

NHTSA ODI 11697872

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

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

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

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

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

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

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

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

The vehicle went into limp power mode while driving

NHTSA ODI 11670036

A month in after purchasing the check engine light came on. My car did not want to accelerate, started shaking and having jerking movement while driving on the freeway with my newborn and 3 other children in the car with me. Got stranded 3 hours away from home. Car has been in the shop going on 30 days. Spark plugs changed, coolant thermostat changed and now the engine was reported that it has failed. Still in the shop currently.

NHTSA ODI 11665959

Engine failed at 52.350 miles due to excessive oil consumption confirmed by a Kia dealership. Car was driving fine on 5/1/25, on 5/2/25, car started to stall with loud clicking noise, and wouldn't move fast, which then activated the check engine light.

NHTSA ODI 11661791

I went to the Garden Grove Kia to get my new 2016 kia optima repaired for their knock sensor settlement repair. By their own terms of the agreement all original and subsequent ow ers can get vehicles repaired. They took my vehicle information, I gave them all details of my ownership of the vehicle and they said they would fix it. The next day I rented a trailer to take the vehicle to get repaired (vehicle still runs but don't think it's safe to drive like that) and upon arriving, a worker comes out and tells me that they will not repir the vehicle because I just purchased the vehicle. Craig, the manager, also refused to see ownership documents but gave me 2 things; legal advice saying that I should sue where I bought the vehicle from and a paper that said they will not fix cars owned by dealers and auctions. I am neither am neither nor. Craig, also stated that Kia wont cover the repairs.

NHTSA ODI 11661385