What 748 owners told NHTSA about the 2016 Kia Optima

My 2016 Kia Optima equipped with the 2.4L DOHC I4 GDI engine began to experience progressive and severe oil consumption during the latter part of my ownership. The oil warning light began activating repeatedly, even after shortly getting the oil changed. Several certified mechanics and oil change service stations told me this was an ongoing issue with this car and engine and that there was nothing I could do but monitor it and keep it filled. At their instruction, I monitored and had it changed more frequently, often topping it off at the oil change station and at home when needed. Approximately 2 weeks after an oil change upon putting the car in reverse it started to shake uncontrollably. The car was towed to a mechanic who stated I needed an engine. I then towed it to an authorized Kia franchise dealership where the technician documented the oil consumption complaint, confirmed a Cylinder 2 misfire code, performed a borescope inspection, and found the Cylinder 2 exhaust valve burnt with a chunk missing. Engine replacement was recommended by the Kia dealership technician. Prior to my purchase, the engine had already been replaced at approximately 80,000 miles under recall-related circumstances. The replacement engine installed by a Kia dealership subsequently failed, exhibiting symptoms consistent with the documented widespread defect affecting the 2.4L DOHC I4 GDI engine in 2016 Kia Optima vehicles, including severe oil consumption, cylinder misfire, and catastrophic internal engine damage confirmed via borescope at a Kia franchise dealership. Kia America denied the claim based solely on mileage despite the damage being confirmed by their franchise technician. My vehicle became unsafe to drive due to this engine instability shortly after starting before becoming fully inoperable. My vehicle has been non-operational for approximately 5 months. Kia has not provided a substantive written determination despite a formal written demand submitted in March 2026.

NHTSA ODI 11744531

The car returned P1326 and had multiple misfires and audible knocking, the dealers will indeed fight the already existing class action warranties. Was sent home and told to “drive the fuck out of it”, to which the car did not make it home and blew gasoline into my cabin while driving on the highway. Almost passed out, and am still fighting Kia to actually address the defective rod bearings. I personally would fight tooth and nail over a 5 dollar problem, but this is something they do nationwide and can cause serious injury or death. If it weren’t a 200 LB man driving the gasoline shooting into the cabin would absolutely cause a knockout. To the time of this report they are still trying to disregard the rod bearing issue and send me home with fixes to problems caused consequentially.

NHTSA ODI 11742694

Car is not holding oil it acts like it's gonna cut off while driving and it jerking was diagnosed with colitic converter p0604

NHTSA ODI 11727436

The contact owns a 2016 Kia Optima. The contact stated that while driving at 60 MPH, the vehicle stalled with the check engine light illuminated. The brake pedal was depressed, and the steering wheel seized. The contact was able to pull over to the side of the highway and contacted the Highway Patrol for assistance. The contact associated NHTSA Campaign Number: 18V907000 (FUEL SYSTEM, GASOLINE, ENGINE); with the failure; however, the VIN was not included in the recall. The vehicle was towed to the residence. The dealer was not notified. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 105,000.

NHTSA ODI 11718486

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

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

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

Driving down the road trying to accelerate. My rpm's wouldn't go over 2000. The engine started fluttering and the accelerator stopped working. Went to take to local repair shop and they stated it was an issue with the engine. problem listed after a scan: OBD P1326 Recall NUMBER: PI1802W/X (Rev 2, 01/28/2019) With this stated. My vehicle under the same Year, Model, Engine, and Production Date are all calling for a recall but my VIN doesn't have a recall. So I am wanting to enquire why my vehicle doesn't have this recall.

NHTSA ODI 11635964

Engine burns over 2 quarts of oil every 500 miles due to carbon build up in engine resulting in engine ceasing up.

NHTSA ODI 11626623

While driving the car will not accelerate past 49mph in turbo mode and 61mph in regular mode and rpm will not go above 1800. And it jerks and studders. Blinking check engine light and consumes a ridiculous amount of oil even though regular maintenance performed. I have read several engine issues with this model and cannot find recall info

NHTSA ODI 11617291

The contact owns a 2016 Kia Optima. The contact stated while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The driver was able to pull over to the shoulder of the roadway, where the vehicle failed to restart. The check engine warning light was illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the fuel pipe and determined that the fuel pipe was leaking into the engine. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 18V907000 (Fuel System, Gasoline, Engine); but the VIN was not included. The manufacturer was not notified of the failure. The failure mileage was 68,000.

NHTSA ODI 11609766

The car had engine failure. The same issue that 1000s of the same make and model had a lawsuit for. Apparently my VIN isn’t one of them covered even though the exact issues stated in the engine failure lawsuit are the same issues I had. It’s under 80,000 miles I get synthetic oil and all other maintenance done when recommended. I was driving one day and the car started jerking and the engine would just stall out there was also a lot of smoke and very loud noises. I have tried contacting Kia and they say that it’s not one of the VIN numbers covered. If it’s the same issue how could they know if it was going to happen to my specific VIN or not. This is a huge safety issue because I am concerned the engine will blow up or catch on fire. I have had a mechanic come look and he started the engine and said to immediately turn it off. This is clearly a safety issue that’s not being handled well at all.

NHTSA ODI 11607159

The contact owns a 2016 Kia Optima. The contact stated while driving at various speeds on several occasions, the vehicle was shuddering with a knocking sound coming from the engine compartment. The vehicle was taken to a dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was repaired; however, the failure persisted. The contact stated that a message "Do not drive - Tow to Dealer" was displayed, and the check engine warning light was illuminated. The vehicle was towed to the dealer where it was diagnosed that a loosened turbo hose needed to be tightened. The vehicle was repaired but the failure persisted. The vehicle was towed to another dealer where it was diagnosed that the high-pressure fuel pump needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 112,000.

NHTSA ODI 11603774

In May of 2023, as I entered an intersection, my 2016 Hybrid Kia Optima suddenly did not feel right and gave me a hybrid system warning error. I pulled to the side of the road and shut it down. I restarted the car. The error light remained on, but the car seemed to drive okay. I finished my short distance into work, and shut it down. I called the dealer and was asked to restart it to see if the hybrid warning light came back on. I restarted it after lunch, and no warning lights came on. The dealer had me bring it in to the service department. They had it for a week or two but could not repeat the problem. They updated the software and thought that might fix the issue. The car worked fine until September 2023 when it suddenly cut out on me as I was turning a corner in my development with the same hybrid system warning error. I was able to glide to the shoulder. I restarted it and drove home with the error warning light. This time the dealer had the car towed into their shop. They had the car for a few weeks but could not diagnose the issue and gave the car back to me with a “trigger” system to monitor for codes. In about a week, the same warning light popped on my wife who pulled over and shut it off. She restarted the car and drove the remaining short distance to work with the hybrid system warning light on. Later that day, it restarted without the hybrid warning light coming on, and I drove it the short distance to the dealer. It took about another month until mid-November to diagnose the problem as a defective hybrid battery and order the under-warranty replacement. Here it is in mid-June 2024 and I am still waiting for a replacement hybrid battery. I no longer trust the car or Kia Corporate, and I haven't been able to get Kia Corporate to respond to me in over a month. Hopefully, no one else is involved in an accident due to this model car cutting out on them.

NHTSA ODI 11594685

Car was at about 70,000 upon purchase. Once driving it regularly, I immediately noticed a faint knocking noise upon acceleration. Also, when coasting the speed adjusted on its own intermittently, both up & down, not by much but enough that I felt it on the gas pedal. Other times it fails to accelerate when pushing on the gas pedal. I have to release the pedal & try again, sometimes more than once before it finally accelerates. Despite doing regular oil changes, my engine burns through oil long before next oil change is due, so I have to add 1 - 2 quarts of oil in-between changes. I was barely at 80,000 miles when engine started seizing & the following day the check engine light came on. It had to be towed to be serviced. They said the fuel injector or pump (not sure which) was allowing fuel to flood my engine which caused its damage. Even with what the warranty covered I had to pay $500 out of pocket so there were a lot of repairs. I can get a detailed print out of service if needed. When I do oil changes there's oil under the oil pan somehow, but its not leaking because there is no oil where I park. As of lately, even though all fluids are good, when the car is idle with a/c on, the temperature starts to go up until the car is in motion again, then the temperature goes back down quickly. It has only overheated once, which was the first time I noticed the problem because I was parked at a gas station on a hot day checking my phone & the a/c started blowing warm & dash said, "engine overheated". Only happen the one time because I have been cautious about watching the temperature to avoid it happening again. I recently passed emissions & had AutoZone do code reader check & nothing came back. In order to figure out problem I'd have to get diagnostics test that requires I leave the car for at least 2 days so it hasn't been something I can manage yet. My car is available for inspection if needed & I'm happy to provide detailed print out of repairs if requested.

NHTSA ODI 11593271

I was told that my engine had a recall on it so I had an upcoming appointment with Kia in like 2 weeks for them to check my engine but the car didn’t make it. I was driving my car on interstate 20 my car had began to have a bad chemical smell and started smoking so I pulled over on the interstate and my car was in flames. Me and my daughter was in the car we could have lost our lives thank God we were able to make it out just in time. The fire department came and made a report on the incident. It wasn’t any engine light on at the time. I have contacted Kia about the tragedy that has happened but nothing has been resolved yet.

NHTSA ODI 11587870

Heavy oil consumption , unintended acceleration , car jerks . Back window occasionally won’t roll down .

NHTSA ODI 11574378

I’m having oil consumption problems. I had this car since 2022 every time I get an oil change and drive 1000 or less miles my oil light comes on when braking or turning vehicle. As well as a knocking sound and the car runs very rough. I put more oil in every time even getting oil change done before I’m supposed to spending extra money and time just to ride in this car. I took it to serval shops no leak was spotted in fact they said my drain plug may need to be replaced. I changed the drain plug twice as that’s not the issue but I’m still having a low to no oil in vehicle. I also was told that i have a cloud of smoke coming out of the exhaust pipe when I hit the gas another problem. More recently after an oil change I’ve noticed a small oil leak spots on the ground. This should be a recall as a lot of Kia owners are dealing with this issue. Help

NHTSA ODI 11569900

My Kia Optima randomly stops working while driving. I get a notice that says, "HEV: Check Hybrid System. Stop Vehicle and Turn Off Engine." Also the gas pedal stops working, leaving me to try to coast to safety. The car essentially stops working in the middle of driving, without warning. Once this happened and blew out the spark plug, requiring a new one. Then, a day or two later, the car returns to normal. The Kia dealership could not reproduce the problem, nor could my service center. They say it's fine. I took my car in for previous recalls, and it is currently "up to date." This appears to be the same electrical issue as a recent recall for electrical failure, but the dealership told me the spark plug was fine and that I should change the battery. I did and this still happened. I do not feel safe driving this car, and Kia won't help me find the problem.

NHTSA ODI 11564189

When accelerating the car will randomly loose all power from the engine. The electrical systems will stay on but the car RPMs will drop to zero. The accelerator will not provide acceleration when being pressed. The car has to be turned off and then turned back on for power to be restored. The check engine light, the oil light and another warning light will come on.

NHTSA ODI 11556705

It started shaking really bad out of no where , then wasn’t going faster than 80 then down to 65 but wouldn’t go more than 80 with my foot all the way on the gas. As soon as I made it to work tonight the car cut off. I got a jump the car was still shaking & wouldn’t stay on if I let my foot off of the gas. I started it again without the cables but it cut right back off. I saw on cars.com it’s a recall for the similar thing, number Sc172. I have been having fuel leaks for a while and had my knock sensor replaced from a previous recall. Now I have no way home.

NHTSA ODI 11552770

I have a 2016kia optima EX and I had a problem with it. I used to take it to the Kia dealership for oil change and services. So recently I have done the transmission fluid and oil change.! After that I have weird transmission problems like it finding hard to accelerate and even when I am changing the gear from park to drive or reverse it makes weird noise like clutching. I spoke with the dealership and they say we have changed the transmission fluid then it shouldn’t be the problem.! They don’t even find the exact problem.! I have been spending a lot on my car . Kia is messing up with the recalls.!

NHTSA ODI 11547644

The fuel gasoline hose line was leaking, so I changed it. Because of that I changed the high pressure pump twice

NHTSA ODI 11547549

The engine was has blown twice the first day 95000 miles and again at under 6000 miles. And there is still a bad knock and major vibration and ticking noise coming from the car. We told the car we no longer have faith in this car and didn't want it no more and all he did was see if he could get us another loan to trade it in. We're now scared to really ride in to and can't get no one to help us on this my man is about to lose his job over this car

NHTSA ODI 11545756

After purchasing the car, the first time I went to fill up the car with fuel I set the fuel nozzle to auto stop. When it clicked off, I pulled the handle out and quite a bit fuel gurgled back out of the fuel tank, like it was over full. I took the car back to the dealership and they checked lines and said it was fine. I took one of the people from KIA with me to show them what it does, and sure enough, did it again. They still say nothing is wrong with the fuel system. It is still a problem, I just am unable to fill up my car all the way.

NHTSA ODI 11543236