2017 Kia Optima: sudden loss of power

Filed Nov 8, 2026 · Engine · NJ

My 2017 Kia Optima LX with the 2.4L Theta II GDI engine has repeated engine misfires caused by oil-fouled spark plugs. The engine burns 1 to 2 quarts of oil every week on only 200 to 250 miles of driving, 4 to 10 quarts per 1,000 miles, far above the 1 quart per 1,000 miles threshold in Kia’s own TSB ENG222. Every time the spark plugs are removed, they are coated with oil. Cylinder #4 has misfired three times in five months (June 5, August, and November 2026), and cylinders #2 and #3 misfired on June 17, 2026. All four ignition coils and spark plugs were replaced in August 2026, and the #4 misfire returned within about three months. We have paid out of pocket for repeated repairs since January 2025. The KSDS update was installed at a Kia dealer. The vehicle is now unsafe to drive because misfires can cause sudden loss of power at highway speed, and running low on oil risks engine bearing damage and seizure. We have taken it out of service. I have written to Kia America’s executives requesting diagnosis under TSB ENG222 and repair under the Theta II settlement’s lifetime warranty. I am asking the federal safety agency to investigate excessive oil consumption and repeated oil-fouled spark plug misfires in Theta II 2.4L GDI engines in 2016–2020 Kia Optimas.

Filed Aug 24, 2026 · Engine · TX

While driving at highway speed, my engine began to produce a loud knocking noise without prior warning. Within few seconds, the engine seized completely causing sudden loss of motive power.This caused a dangerous situation— loss of power steering and barking at highway speed, leaving me stranded in traffic lanes. I was forced to coast to the shoulder. The vehicle was towed to the nearest independent repair shop because it was not drivable and I was stranded far from home. The shop diagnosis —- seized engine due to big end connecting rod bearing seizure, identical to the federal safety agency Recall 17V‑224 and KIA recall SC 17/ SC165 and TSB P1803 related to Theta engine bearing wear and engine seizure.My vehicle has the 2.4 L engine covered by this recall/defect.The failure occurred exactly as described in the recall: knocking , the seizure. KIA has denied warranty coverage because the vehicle was initially diagnosed and repaired at independent shop after the roadside emergency.The shop was used only because the vehicle was immobilized on the freeway away from home. I did attempt to contact a dealership in FortWorth, Texas, Morits KIA, but they could not provide roadside assistance or a tow solution at that time. I am reporting because: 1) This is a sudden loss of power at highway speed, which is a major safety risk 2) This appears to be the same defect KIA has recalled for, but the vehicle was not remedied or remedy failed 3) KIA is refusing to honor the extended warranty for this known defect I request the federal safety agency document this failure as part of the ongoing monitoring of Theta II engine failures. Vehicle is available for inspection and defective engine have been preserved.

Filed Jun 30, 2026 · Steering · MA

Since 4/1 my car has intermittently lost power steering. I received dashboard warning lights and the wheel was difficult to turn. When I shutoff the car and turned back on, the warning lights were gone and the steering returned. My mechanic did a diagnostic and found the following codes c1259, c1260, c1290 and c1688 each time the incident occurred. After research, we discovered these codes relate to TBS CHA114 and TSB CHA864 under extended warranty WTY023. I was unable to upload the TBS documents. The same thing happened on 6/18. I brought the car to a different dealer. The first time they supposedly did a diagnostic and said there were no codes. I have pictures of the codes. They said it did not matter because the codes need to be active and the lights need to be on the dashboard. The second time at a different dealer, they didn't do a diagnostic but said it did not matter because the codes need to be active. No where is any documentation does it say the codes need to be active. They are stored in history and Freeze frame data. It is impossible for me to get the car there with the illuminated dash and "active" codes because when it happens, I cannot steer the car and when I shut if off they go away. Plus when I get to the dealer, they will tell me they cannot take me and to make an appointment. I am now working with KIA escalation department but she informed me today that she did not have the authority to authorize a dealer to repair the car. When I asked who does she said I need a techline which is opened by the dealership. WHAT??? This all started with the dealer. The car is now having glitches with the steering while driving. IT IS DANGEROUS AND I AM AFRAID TO DRIVE IT. I have no idea when the steering might go out. I need help in getting a Kia dealership to fix the issue under the extended warranty they sent me in 2022. I am so sick of the run around and brush off. How do I get this accomplished?

Filed Mar 24, 2026 · Engine · VA

Engine issues started the third month after sales. Jerking, shaking, declining performance, metal clicking noise, loss of power while driving. Kia has been working on the car for a year.

Filed Jan 4, 2026 · Engine · ND

Kia Engine Settlement-Kia America and Grand Forks KIA dealership is refusing a mandatory diagnostic test for excessive oil consumption under the Kia Theta II Engine Class Settlement, despite the vehicle having the required KSDS software update installed. The vehicle is consuming 1 quart of oil every 1000 miles, requiring constant topping off to prevent engine seizure. Vehicle was brought to Kia Grand Forks on 7/21/25 was told that the valve gasket needed to be changed. Engine light illuminated 10/2025 and car was unable to make it back to dealership from 58369. Vehicle was brought to local mechanic where I was told that the has failed and that the spark plugs had oil on them. Mechanic changed the spark plugs to make it to Grand Forks Kia on 10/14/25 I was told that the Turbo needed to be replaced for $3300 before they can do an oil consumption test. There were no issues with the turbo before it was driven to Grand Forks on 10/14/25. Kia America refuses to cover the engine warranty which will lead to "sudden engine stall, loss of power, or vehicle fire," which are primary safety concerns monitored by the federal safety agency.

Filed Dec 9, 2025 · Engine, Transmission · IL

Vehicle experiences sudden and dangerous loss of power while driving, including hesitation during acceleration, consistent with connecting-rod bearing failure risk known in this model’s GDI engine. Dealer estimate found timing and oil-flow component failures connected to internal engine damage. Vehicle is unsafe to drive and stalls/lacks power unexpectedly, creating a high risk of crash.”

Filed Nov 16, 2025 · Engine, Fuel system · CA

I own a 2017 Kia Optima with a major internal engine defect. Starting shortly after purchase, the car lost power and consumed fuel unusually quickly. Over time, the engine began burning excessive oil and now produces a loud knocking sound (bearing knock), indicating internal bearing failure. These symptoms are consistent with known Kia engine defects (bearing wear / piston ring failure). The defect is a serious safety concern: because of weak bearings and high oil consumption, the engine could stall, seize, or catch fire. The dealership has refused to repair or replace the engine. I am reporting this as a safety defect and request the federal safety agency investigation.

Filed Jul 30, 2025 · Engine, Transmission · GA

Excessive oil consumption started at 61,000 miles, causing engine misfires and dangerous power loss on the road. Engine codes 1326 and P0304 were frequent. Despite numerous services, including sensor replacements, spark plugs and oil top-offs, the problem worsened. At 97,769 miles, the dealer said a full engine replacement is needed along with other pertinent repairs related to the engine are needed. The situation was life-threatening each time as they occurred while driving and I now no working vehicle after my husband's recent death. Kia dealerships acknowledged the defect but refused to replace the engine and advised that Kia Corporate was refusing, although no claim information was ever provided that they indeed contacted the corporate office. I am seeking the federal safety agency support in holding Kia accountable.

Filed Jun 3, 2025 · Steering · NJ

Randomly when turning, my steering will jolt in the opposite direction and lose power steering. The red power steering light does come on at this moment where I have to pull over, turn the car off, and restart and the symptoms clear itself up. In addition, there is there is, randomly, grinding noises (and I can feel it in the steering) when turning. When this occurs, relocating the steering column by changing the position (via tilt and telescopic) seems to help clear it up for awhile. I have almost jolted to oncoming traffic when turning and a few instances. I have had it serviced to check steering points at tires, axel, cv joints, and my mechanics can't seem to find the fault there. Even after doing alignments, it helped for a little bit but the same problems came back. They believe it to be a steering column issue. They believe that it is getting caught when turning and causing the issues. This has been occurring for about 6-8 months now. The power steering losing power happens maybe once or twice a week to once every two weeks. The grinding and vibration in the steering column while turning happens a few times a week to maybe just once a week. Its occurrence worsens when it rains. I am reporting this because I have read other reports of people have the same experience as myself.

Filed Apr 5, 2025 · Engine · OH

I was driving on the highway, the check engine light started flashing and the car lost power. This created a very dangerous situation because I could not go the speed limit and could not get off the highway since I was in the middle lane. We went and had the check engine light checked and were told the code was P1326.

Filed Nov 13, 2024 · Engine, Fuel system · CA

A auto repair shop said my Kia Optima has a bad knock sensor which is a common problem with those cars. My safety and others was put at great risk when I suddenly lost power on the freeway Problem was confirmed at an independent service center Has not yet been inspected by manufacturer Warning message came up at the same time as losing power

Filed Aug 30, 2024 · Steering · IA

Car engine stuttered when turned on, then after a moment smoothed out . I noticed some looseness in response in the steering wheel while driving forward, after a short period of time driving the antiskid symbol and the EPS symbol came on and I lost power steering. I turned off the car and turned it back on . The emergency symbols were gone and the power steering was OK. I headed back home and the symbols came back on and lost power steering again after driving about 3 blocks. I repeated turning car off and on to get home.