2018 Kia Optima Problems

See attached document for complaint.

I’ve had my 2018 kia optima for round about two years.I only got this car because they refused to replace my previous engine on my 2015 Kia optima,even though I had a warranty but that’s another story(Kia on the Blvd).This car have given me problems from the start.Going through oil in less than a month,which they can never find a leak,not being able to go over a certain speed before I start to hear noises.Ive complained about noises,they act like they can’t hear,and said nothing is wrong with the engine when previously checked.My check engine light has came on twice and both times the car was malfunctioning on the highway resulting in me have to get a tow.First it was plugs replacement now I need a whole new engine.I really don’t know what to do at this point.I believe they sold me a faulty car

I am submitting this complaint regarding ongoing and persistent mechanical issues with my vehicle since the time of purchase. The vehicle has repeatedly shut off unexpectedly, creating a serious safety concern. Initially, I suspected the issue might be related to the battery, and I have replaced the battery twice within the past 4 years. However, the problem has continued. In January, the vehicle began shaking and shutting down again. I took it to a mechanic, who diagnosed the issue as faulty spark plugs and an ignition coil. The diagnostic codes provided were P0303 and P0456, and the recommended repairs were completed. Approximately one month later, the vehicle began shutting off again. I then took it to the dealership, where I was advised that the valve cover gasket needed to be replaced, along with the belts, and that a fuel system cleaning was required. I subsequently had these repairs completed by my mechanic. Less than a week after completing those repairs, the vehicle once again began shutting down. A diagnostic scan then produced code P123300. In addition to these repeated shutdowns, the vehicle consumes an excessive amount of oil, has poor acceleration, and continues to stall unexpectedly both while driving on the road and while idling, such as in a drive thru. These recurring issues have made the vehicle unreliable and unsafe. I am concerned about the risk of the vehicle shutting off while in motion, which could lead to a dangerous situation. I am requesting that this matter be reviewed for potential defects or safety-related concerns.

I turned the car off, it had difficulty turning back on and the brake pedal got really hard. I had to wait about 30-45 minutes and then I was able to get the car started and brake pedal back to normal and no lights. Recently, I left the car on to run into a shop real quick and come back out. When I got back to the car, the power steering light, battery, and warning light?(amber triangle with ! In the center of it) were all on. I rev the engine and the issue went away for a quick second but then came back on. To avoid turning my car off and being stuck, I just shift to reverse and tried to leave. I’m backing out of the spot and now the backup camera is going in and out lights flashing on the dash and I’m trying to brake but the brake pedal isn’t registering and next thing you know, I’ve backed into a guard rail. On the way to drop my kids off at the babysitter, I was coming to a stop sign, and my car wouldn’t brake, i went through oncoming trafic and had to run off the road. KIA did a multi point inspection a few months apart from one another. One the car tested fine, then the second time they are saying a brake booster and no engine oil in the vehicle and that the car is basically trash. The oil light goes on and off and I can smell burning oil. I still owe 7 grand on this car and I just bought it last year and it was seamingly fine.

There is already the theta 2 campaign on my Kia optima but Kia is not upholding their warranty for a new engine. Kia customer care told me that untill my car actually throws a rod then they will not fix it. So I could be doing 80 down the freeway and jeopardize not only my safety but everyone else's for them to uphold their lifetime warranty? Also upon doing further investigation and I don't know how many cars this pertains to but the fuse box in my 2018 actually belongs to a 2016 which if you look it up yes they are comparable but don't offer all the same functions or power that my 2018 needs to run I fully believe Kia knew this when they were being built on the factory line because it just so happens that there is about 6 different versions to the pcb relay that can fit from a 2016 to a 2020 k5 but for some odd reason every car got something different why?

My engine burns oil very bad. Black smoke comes out of my tailpipe and I burn through 5 quarts in less than a thousand miles. I just got my oil changed two weeks again and I just had to add more oil to my car bc it was empty. I’ve had to replace the spark plugs twice due to soot build up. I can’t afford a new car I’m 17 and can barely afford the maintenance let alone a whole new engine. Have spoken to many mechanics and they all say the same thing “it’s a Kia it’s gonna burn oil” ITS A KNOWN ISSUE. And yet Kia will not resolve it bc they don’t want to spend their own money to fix their mistake. I got an estimate for a new engine which is basically crucial and it’s over three grand. No matter where I take it everyone always says the same thing- to get rid of it before it’s too late. But I simply cannot afford to do that and I know my car is not the only one with this issue so many other people with the same car/engine have the same issue. 2.4 L GDI !!!!! I wish someone would have warned me before buying Kia. A recall to fix this issue is needed now. I lose control of the speed sometimes. I will keep my foot at a set position on the throttle and the engine will take off because it’s jumping to the usual power it should have. ( it has reduced power most of the time bc of the struggling engine) sometimes on the highway I’ll get a sudden burst of power and I have to let off the accelerator. Not safe at all

Purchased car about 4 months ago, before warranty ran out, the shop looked at it told me it was fine, it wouldn't accelerate. Few weeks later same issue but all my oil was gone, they found 11 things wrong with the vehicle, told me warranty wouldn't take care of it unless the engine blow up. The salesman Scottie Mitchell told me check Kia for recalls, called Kia 3 recalls, they were trying to finance another car higher, back wanted to know why the dealership didn't know about recalls, Kia place did call a Robert. One of the owners did know about recalls, why dealership didn't pass them on. They trying to sell me a higher vehicle to keep cover the cost of the one I got 1st

My engine burns oil very bad. Black smoke comes out of my tailpipe and I burn through 5 quarts in less than a thousand miles. I just got my oil changed two weeks again and I just had to add more oil to my car bc it was empty. I’ve had to replace the spark plugs twice due to soot build up. I can’t afford a new car I’m 17 and can barely afford the maintenance let alone a whole new engine. Have spoken to many mechanics and they all say the same thing “it’s a Kia it’s gonna burn oil” ITS A KNOWN ISSUE. And yet Kia will not resolve it bc they don’t want to spend their own money to fix their mistake. I got an estimate for a new engine which is basically crucial and it’s over three grand. No matter where I take it everyone always says the same thing- to get rid of it before it’s too late. But I simply cannot afford to do that and I know my car is not the only one with this issue so many other people with the same car/engine have the same issue. 2.4 L GDI !!!!! I wish someone would have warned me before buying Kia. A recall to fix this issue is needed now. I lose control of the speed sometimes. I will keep my foot at a set position on the throttle and the engine will take off because it’s jumping to the usual power it should have. ( it has reduced power most of the time bc of the struggling engine) sometimes on the highway I’ll get a sudden burst of power and I have to let off the accelerator. Not safe at all

Purchased vehicle from a used car dealership. Had it a few months before brake pedal started losing pressure and going to floor. Had master cylinder replaced. A few months later, brake light started coming on when accelerating. New master cylinder had leaked into brake booster. Had master cylinder replaced along with brake booster. A few weeks later and brake pedal is losing pressure again

I turned the car off, it had difficulty turning back on and the brake pedal got really hard. I had to wait about 30-45 minutes and then I was able to get the car started and brake pedal back to normal and no lights. Recently, I left the car on to run into a shop real quick and come back out. When I got back to the car, the power steering light, battery, and warning light?(amber triangle with ! In the center of it) were all on. I rev the engine and the issue went away for a quick second but then came back on. To avoid turning my car off and being stuck, I just shift to reverse and tried to leave. I’m backing out of the spot and now the backup camera is going in and out lights flashing on the dash and I’m trying to brake but the brake pedal isn’t registering and next thing you know, I’ve backed into a guard rail. On the way to drop my kids off at the babysitter, I was coming to a stop sign, and my car wouldn’t brake, i went through oncoming trafic and had to run off the road. KIA did a multi point inspection a few months apart from one another. One the car tested fine, then the second time they are saying a brake booster and no engine oil in the vehicle and that the car is basically trash. The oil light goes on and off and I can smell burning oil. I still owe 7 grand on this car and I just bought it last year and it was seamingly fine.

My cars bulbs have been blowing on a regular basis for two years..some of the bulb connections are catching fire and exploding .Ive changed on numerous occasions but doesn’t matter even with new fittings…obviously an electric problem

Kia Optima headlights turn off randomly while on automatic. This dangerous issue has been investigated on other Kia models by the NTSB, which them prompted Kia to issue a recall. I have found many, many posts on car and Kia forums about headlights shutting off while driving at night with the Kia Optima (as well as other Kia items). It's very scary and very hazardous. This is a widespread issue.

I am submitting this complaint regarding ongoing and persistent mechanical issues with my vehicle since the time of purchase. The vehicle has repeatedly shut off unexpectedly, creating a serious safety concern. Initially, I suspected the issue might be related to the battery, and I have replaced the battery twice within the past 4 years. However, the problem has continued. In January, the vehicle began shaking and shutting down again. I took it to a mechanic, who diagnosed the issue as faulty spark plugs and an ignition coil. The diagnostic codes provided were P0303 and P0456, and the recommended repairs were completed. Approximately one month later, the vehicle began shutting off again. I then took it to the dealership, where I was advised that the valve cover gasket needed to be replaced, along with the belts, and that a fuel system cleaning was required. I subsequently had these repairs completed by my mechanic. Less than a week after completing those repairs, the vehicle once again began shutting down. A diagnostic scan then produced code P123300. In addition to these repeated shutdowns, the vehicle consumes an excessive amount of oil, has poor acceleration, and continues to stall unexpectedly both while driving on the road and while idling, such as in a drive thru. These recurring issues have made the vehicle unreliable and unsafe. I am concerned about the risk of the vehicle shutting off while in motion, which could lead to a dangerous situation. I am requesting that this matter be reviewed for potential defects or safety-related concerns.

On August 26, 2025, I brought my 2018 Kia Optima Plug-In Hybrid to an authorized dealer for recall SC218 (engine inspection and KSDS software update). The dealer verbally stated both SC218 and SC278 recalls were completed, and the repair order (RO #XXX) lists them as performed. In September 2025, Kia America emailed me showing recall SC218 still open, and a warranty coverage report dated September 26, 2025, again listed SC218 as unclosed. On November 4, 2025, NHTSA’s official VIN lookup confirmed the recall remains “Incomplete.” On October 21, 2025, Kia America emailed me under Case #XXX stating that SC218 was “confirmed completed” and that the dealer performed a software update to the ECU, referencing RO #XXX. However, NHTSA’s database still lists recall SC218 as incomplete. This contradiction between Kia America’s internal record, the dealer’s invoice, and the federal NHTSA database raises a serious safety concern that the recall inspection or software update was never actually performed or was never reported correctly. I have requested written proof and diagnostic data (Battery SOH report) multiple times but have not received them. If accurate, this means I was led to believe my vehicle’s engine-safety recall had been repaired when federal records still list it as open. I am requesting NHTSA to review this reporting discrepancy, ensure Kia America and the dealer produce verifiable proof of completion, and confirm that the federal record is corrected. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Steering column coupler went bad. Unable to swap out the coupler alone ($12 part) and had to get a whole new column (over $1200). Some of the Kia's around this one's make and model were recalled but not this one. Without this repair driving would have been dangerous.

Check engine light began flashing halfway down the highway. Oil changes and maintenance are done regularly. Vehicle handling seemed to be unsafe. Vehicle would not accelerate. Had inspection done in September.

I was run off the road by a drunk driver I hit a tree at 35MPH MY AIR BAGS DID NOT DEPLOY NOR DID MY SEAT BELT LOCK!!!! I NOW HAVE MULTIPLE INJURIES I HAVE BROKEN BONES ALL THROUGHOUT MY FACE!!!!! A SEVERE CONCUSSION!!!!! Any time I call the the customer care center and try and get information or call someone I either get hung up or gave the run around and then hung up on my mother in law has also tried calling and have received the same response this is so unacceptable and unprofessional.

I was rearended, all air bags deployed except steeringwheel

My teenage daughter regularly drives this vehicle. The vehicle began experiencing significant oil consumption, oil leaks, and intermittent loss of power. During an early inspection at an independent repair facility, a check engine code P1326 was identified. Due to the symptoms and diagnostic code, the repair facility advised that the vehicle could be heading toward engine failure and recommended that the vehicle be taken to an authorized dealership because potential engine issues may fall under manufacturer warranty coverage. The vehicle was then towed to an authorized dealership. During the first visit, the dealership retained the vehicle for an extended period of time, approximately two months. During that visit, several recommended services were completed, including replacement of spark plugs, ignition wires, and replacement of the valve cover gasket along with other recommended maintenance. During that visit, it was also stated that the vehicle has a known issue with excessive oil consumption. Because of this, the oil level is checked weekly and oil is added as needed. I also informed the dealership that the independent repair facility had identified code P1326, but I was told that the dealership diagnostic codes were different. After these repairs, the vehicle experienced another incident where it lost power and began idling roughly while being driven on a busy highway. The vehicle was taken back to the dealership. During that visit, it was stated that the fuel injector harness and oil pressure sensor needed to be replaced. The dealership also indicated that the spark plugs needed to be replaced again, even though they had been replaced at the same dealership less than a year earlier. At that time, I asked if the vehicle would be safe to drive for approximately one week because I needed to travel out of town and my daughter would need the vehicle. The dealership advised that it was safe to drive during that time. The vehicle was then brought back to the deal

About a month ago my paint on my 2018 Kia Optima snow white pearl car started bubbling, then it turned into peeling and has since then been coming off more and more. It is occurring right under the back seat of the drivers side window. Reading into this issue more, it is happening to many who own a Kia Optima owners, especially those who own the snow white pearl color. Kia is not helping customers who are out of warranty but since this is a manufacturer defect they should be, even if they are out of warranty.

I was run off the road by a drunk driver I hit a tree at 35MPH MY AIR BAGS DID NOT DEPLOY NOR DID MY SEAT BELT LOCK!!!! I NOW HAVE MULTIPLE INJURIES I HAVE BROKEN BONES ALL THROUGHOUT MY FACE!!!!! A SEVERE CONCUSSION!!!!! Any time I call the the customer care center and try and get information or call someone I either get hung up or gave the run around and then hung up on my mother in law has also tried calling and have received the same response this is so unacceptable and unprofessional.

Passenger seat belt goes off when no one is sitting there.

The car caught on fire in our driveway

I WAS DRIVING ON A HIGHWAY AND STARTED TO HEAR AN NOISE FROM THE FRONT RIGHT WHILE I WAS ON A ROAD TRIP. HAD BEEN DRIVING FOR ABOUT 45 MILES AND MOVED OVER ONE LANE TO THE RIGHT AND FRONT RIGHT TIRE BLEW - HAD LESS THAN 16,000 MILES ON CAR. I GOT THE TIRE REPLACED AT A KIA DEALERSHIP AND WHEELS ALIGNED. THEN,DRIVING ON A MAIN ROAD, 45 MPH A FEW WEEKS LATER, GOT TO A PASSING ZONE, AND PASSED THE CAR IN FRONT OF ME AFTER ACCELERATING TO 65 DURING THE SHORT PASSING ZONE. AFTER PASSING THE CAR I TAPPED THE BREAKS TO SLOW BACK DOWN TO 45 AND THE TRACTION, BRAKE, AND TMZ LIGHTS ALL CAME ON. WHEN BRAKE ENGAGED, CAR DID NOT BRAKE AS NORMAL AND A ODD NOISE LIKE A GRINDING SOUND COULD BE HEARD COMING FROM THE FRONT RIGHT WHEEL AREA. TOOK THE CAR INTO DEALERSHIP, THEY RAN DIAGNOSTICS, SAID IT WAS A 'MISS-TRIPPED' SENSOR AND CLEARING IT CORRECTED THE ISSUE. I DROVE MY CAR LESS THAN 5 MILES DOWN THE ROAD AND ENGAGED THE BRAKE ON A 40 MPH ROAD AT A STOP LIGHT, ALL THREE LIGHTS CAME RIGHT BACK ON. HAD TO CALL AND TAKE CAR BACK IN AND THEY ENDED UP KEEPING MY CAR SEVERAL DAYS BEFORE SAYING I HAD A BAD TIRE SENSOR, BUT CAR WAS SAFE TO DRIVE. DROVE AGAIN, TO A NEIGHBORING CITY AND HAD BEEN DRIVING ABOUT 40 MILES AND FRONT LEFT TIRE BLEW. GOT IT TOWED BACK TO THE DEALERSHIP, WHO SAID TIRES BLOWING HAD NOTHING TO DO WITH CENSOR. GOT TIRE CHANGED AND ROTATION. PICKED UP CAR AND TIRE PRESSURE LIGHT CAME ON -LOW PRESSURE. NITRO WAS ADDED BY DEALERSHIP AND LIGHT WENT OFF. TURNED MY PRESSURE READER ON AND 2 MILES DOWN THE ROAD THE CAR WENT FROM 37 TO 45 PSI. I THINK BAD SENSOR IS CAUSING OVER INFLATING OF TIRES AT THE DEALERSHIP LEADING TO BLOWN TIRES.TESTED PRESSURE WITH SEPARATE PRESSURE READER AND TOO HIGH SO LET SOME AIR OUT, DROVE DOWN A HIGHWAY AT 50 MPH AND CAR 'BOTTOMED OUT' ON A ROLLING DIP IN THE ROAD SCRAPPING THE PLASTIC PROTECTION PIECE BEHIND THE FRONT RIGHT TIRE UNDER THE CAR

The contact owns a 2018 Kia Optima. The contact stated that while attempting to accelerate from a standing start the vehicle had experience sever jerking and hesitation. Also, the vehicle has experience oil consumption problems and the contact constantly added engine oil. The cause of the failures were not determine. Also, the hood latch had malfunctioned and the hood could not opened to add oil to the engine. The cause of the failures were not determined. The local dealer and manufacturer were notified of the failures but no assistance was offered. The failure mileage was 121,000.

I purchased my 2018 Kia Optima directly from the dealership, brand new. I've had the vehicle since then and have followed all of the warranty guidelines and only went to them for oil changes & other maintenance issues. Since February 2023 I've noticed where i've been having oil loss, but no sign of an oil leak. When I first noticed this, I would take a turn and my oil light would come on. I'd check the oil and it'd be low so I would refill my oil. However, this was happening 2 months after my last oil change which wasn't normal. I took the vehicle to Kia and they did an "Engine Consumption Test" where I had to drive for 1000 miles with a seal on the drain plug. After the 1000 miles, I came back and I was only 1/2 quart low. According to Kia it didn't meet the guidelines for engine replacement so they topped off my oil and I left. About 2 weeks after, my oil light came back on. I went back to Kia and spoke with the Shop Manager who stated I was 3 1/2 quarts low! He added oil to my engine and we did another round of the consumption test. When I came back in after that, I was 2 quarts low so that meant I qualified for a "Consumption Cleaning". They kept my vehicle overnight & I had to drive another 1000 miles. When I came in after my 1000 miles again I was only 1/2 quart low and therefore Kia said there wasn't an issue. I've reached out to multiple auto repair shops who state it is a Kia problem, that the engine is using it and processing it out of the exhaust. I don't know what else I have to do in order for Kia to honor the 20 year, 200k warranty. I have all documentation for all of my oil changes and from the consumption tests also.

ON NOVEMBER 7 WHILE DRIVING ON A FREEWAY IN SC I HAD A CATOSTROPHIC FAILURE IN MY FRONT LEFT TIRE AT 55 MILES PER HOUR. FORTUNATELY I WAS ABLE TO EXIT SAFELY AND GET MY VEHICLE OFF THE ROAD. THE TIRE WAS FILLED TO MANUFACTURER PSI AND WAS DRIVEN ONLY 13,151 MILES. THE SIDEWALL WAS BLOWN OUT. I DID NOT HIT ANYTHING TO CAUSE THIS FAILURE THE TIRE IS A KUMHO 215 R17 94 V. MY VEHICLE IS A 2018 KIA OPTIMA S. I BELIEVE I SHOULD HAVE A FULL REPLACEMENT FOR THIS FAILURE.

Was driving vehicle on freeway, around 65 mph, smooth road, no bumps, no indication of any road debris and suddenly heard a loud cracking/exploding noise which was extremely startling. After hearing some outside wind noise and the sound of glass pieces rattling, I realized that the glass panoramic sunroof must have broken somehow. Luckily I had the interior fabric shade closed, so no glass pieces entered the cabin to injure anyone. After getting out of the car, I could see around a 12 inch diameter hole in the sunroof glass. The remaining glass that was still attached was full of cracks. I have created a case with Kia Consumer Affairs and waiting to hear back from them. The vehicle has not received any outside inspection as of yet for this incident. There was no prior warning to this issue, no creaking noises or visible cracks.