There are 22 owner-reported powertrain & transmission complaints for the 2020 Kia Optimain NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
My engine has failed. This is the second car I’ve had from Kia that the rod barring has failed.
I have kept up on regular oil changes and maintenance on my Kia which I bought new 5 years ago. My issues started when my car's orange check engine light came on, I experienced loss of power such as difficulty accelerating even at low speeds, especially up hill. As soon as I was able I checked my oil which and there was nothing on the dipstick. I put in 3 quarts of oil. I brought it into my usual dealership for service and let them know about the oil issue and issues with power when driving. They failed to address the root cause of the issue, they performed an oil change, engine light turned off, and they started an oil consumption test. But when I drove off the lot the issue with the power continued, and the check engine light came on again. I took my Kia to another dealership to address the car's power issue and the first oil consumption test was not completed because it was unsafe to drive. When I brought my car in, the check engine light was not on, even though there were significant power issues. The dealership was able to confirm my concern, including loss of power and evidence of oil overconsumption. They replaced my turbocharger under warranty. I then underwent a 2nd oil consumption test that indicated overconsumption at a level of 1.5 quarts per 1000 miles. Then they performed a combustion chamber cleaning per Kia guidelines and a 3rd oil consumption test. They 3rd oil consumption results indicated overconsumption at a level of 0.75 quarts per 1000 miles. Although the dealership acknowledged this is still overconsumption, it was not to a level that required Kia to replace my motor. Meanwhile, after all these tests my car is close to out of warranty, at 98.6k miles. I called Kia customer care and their "resolution" to my case was the deny me a new engine and they would not provide me anything in writing. My car's overconsumption of oil and other signs of engine failure match the complaints found in class action settlements related to other Kia models.
Engine knocking and stalling on interstate
2020 Kia Optima LX 2.4, LESS THAN 100,000 miles on car. Car started over consuming oil 2 quarts/1,000 miles. Cranked engine yesterday to go to work and serious knocking sounds, engine is rattling severely. Losing revving power, undriveable. Smoke coming out of exhaust that smells like rotten eggs. Will be taking this to get codes run but I believe this is due to Theta II engine failure issue reported in similar cars with the same engine. KIA NEEDS TO COVER THE 2020 OPTIMA UNDER LIFETIME WARRANTY PROTECTION otherwise this is a $10,000 cost to replace engine.
When the vehicle was about 3 years old and at 60,000 miles, the fuel injector went out. Kia took weeks to approve the replacement under warranty. Since then the engine light came on and said cylinder 3 has leak and fouls the plug. We've had it repaired 3 times. The mechanic said it would be too costly to repair and the engine should be replaced.
After complaining about clutch judder resulting in getting anti-judder logic software update, followed a month later by transmission serviced, transmission suddenly failed while driving in heavy traffic on the freeway. After repairs, judder keeps happening at low speeds on the freeway or slow speeds under load.
Accelerating at a normal rate to get on the highway and the check engine light starts flashing out of nowhere and car goes into limp mode. Made it to local shop and they informed me it was a P1326 code and that a knock sensor would have to be replaced, but that Kia has recalled the older models for this same reason.
Code P1326 and oil pressure light keeps flashing
The engine in my 2020 Kia Optima S (2.4L GDI Theta II) has been experiencing excessive oil consumption, engine knocking, and loss of power, consistent with known issues in earlier model years of this engine. This component is still in my vehicle and is available for inspection upon request. The issue puts my safety at risk due to unpredictable power loss while driving and the potential for engine seizure or fire, especially during high-speed travel. I’ve had to top off oil multiple times between regular oil changes, and the vehicle showed signs of low oil without any dashboard warning. No KSDS (Knock Sensor Detection System) software was ever installed on the vehicle. I have not yet had a full diagnosis from the dealer, but I have opened a case with Kia Consumer Affairs, who informed me that I do not qualify for recall repair based on the vehicle’s manufacture date — despite the engine matching those in previous lawsuits and recalls. The vehicle has not yet been inspected by the dealer, manufacturer, police, or insurance representatives. However, I can provide receipts for oil purchases and logs documenting how often I’ve had to refill the oil. I am also filing a claim with my third-party powertrain warranty provider. Symptoms first appeared at approximately 85000 miles Engine knocking/ticking noise Oil light flashing briefly or low oil found without warning Needing to add 1–2 quarts of oil between oil changes Rough acceleration or loss of power This issue is widespread, has been previously acknowledged in other model years, and should be formally investigated in the 2020 Optima as well. I am concerned for the long-term safety and reliability of this vehicle
I was driving on the high way and the car loose power completely have to do change oil every two weeks and can’t find a solution
I am filing this complaint due to severe and ongoing safety defects in my 2020 Kia Optima EX, which has repeatedly stalled while driving, creating a life-threatening road hazard. Since September 2024, my vehicle has suffered from major failures, including a complete transmission replacement, multiple high-pressure fuel pump replacements, multiple oil flushes due to fuel contamination, and all fuel injectors replaced. Despite all of these “repairs” performed by a Kia-authorized dealership, the check engine light continues to return, and the vehicle still stalls unexpectedly, making it dangerous to drive. On March 10, 2025, after Kia claimed to have tested the vehicle for 200 miles, I picked up the car from the dealership, only for it to stall and trigger the check engine light within hours before I even reached my destination. This vehicle has been returned to me multiple times in an unsafe condition. Additionally, an independent mechanic discovered an engine oil leak and a torn axle that Kia’s dealership never disclosed. This raises major concerns about their lack of proper inspection and repair procedures. This is a serious safety issue that Kia refuses to take accountability for. I request an immediate investigation into this matter before this defect leads to an accident.
The vehicle experiences a dual-clutch transmission shudder in low gears and at low speeds. This issue causes a sudden loss of speed in situations such as merging onto a highway, leaving a parking spot, or while driving at approximately 30 mph. The shudder occurs randomly and poses a serious safety concern. The problem first appeared in 2020 when the vehicle had fewer than 5,000 miles on it. Beginning in 2024, at around 20,000 miles, the condition began escalating rapidly, with the shudder occurring more frequently and with greater severity. All incidents have been recorded on dash cam and provided to the dealership’s service department. The vehicle has been serviced multiple times for this issue and was kept at the dealership for approximately six weeks in total. Despite this, the dealer refuses to acknowledge the problem, citing the absence of warning lights. When the clutch was adjusted at my request, the issue temporarily improved but returned about three weeks later. The shudder now occurs more often and with greater severity, frequently forcing the driver to pull over for safety. This ongoing transmission defect creates unsafe driving conditions, and the lack of acknowledgement or permanent resolution by the dealer further increases the risk to the driver and others on the road.
Was on highway going 65, check engine light started flashing loss power. Couldn't go over 2000 rpms car would struggle to accelerate, car had been using up oil like crazy the week before. Stopped at an autozone car read code P1326.
I started having clicking sound in engine around 50k miles . Then my check engine light came on and my engine has been using so much oil. I have to get an additional 3 quarts in between oil changes. The clicking sound is getting louder and my car is now having issues accelerating. . My engine is failing and I bought this car brand new and have regularly maintained it .
At gas, the vehicle jumps/judders as if it’s not getting enough gas to get up and go, and then at higher speeds it goes fine. Was reported to Horne Kia while under warranty. They never found the issues. Months later issue was found by a new mechanic, now the vehicle is no longer under warranty and the TRA codes are posted online. [XXX] Reported August 2021 [XXX] Reported December 2020 INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Leased this Kia by force from rightway auto here in Indianapolis in. Had for about 1 1/2. First notice after filling up my tank gas was depleted within 3 days on driving 12 miles to and from work in town. Then oil start disappearing a week after oil changes. .around Jan 8,2024. Check engine light start flashing driving the highway to work. Speed jumped down to 45. Engine start shaking if I tried to go faster. Got a engine light scan says needs knock sensor. Had it replaced. 6 months later. Car did the same thing. Same code. Knock sensor. Had it re replaced. 3 hours later car did the same thing. Each time while driving the highway almost got me rear ended. On June 27,2024 took it to ray skillman dealership. Found out knock sensor needed to be replaced again, this time along with plugs n worse apparently knock sensor throwed off spark plugs. Was told it's consuming a lot of oil they don't know why cause there's no leaks. Spent over 800 at the dealership. After paying 320. Replace part. Then another 140. Replace that replaced part. Less than a week after spending 800 at the dealership. [XXX].on my way to work my car did the same thing driving on the highway where the speed limit I think is 70. Cars flying. And almost got rear ended again. Cause the speed of the car dropped to 45, engine light start flashing. Car started shaking.. so again I'm out of a car cause it has to go back to the dealership. Not enough money for lift to work n home. About to lose my job. Just paid my car note on the 23 of june at 700 plus insurance 175.. 1300 for rent. And a minimum wage paying job at the airport. Apparently the 5 yr warranty on the car is up when I just reached 10000 miles . And I only had this car for less than 2 years I think it had 90 something thousand miles on it when I got it..i guess the makers of this car knew this trash would only last 5 yrs . reason why it came with a 5 yr manufacturer warranty Can someone please help. We the people are out of money. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
My 2020 Kia Optima had engine failure and engine is being replaced now. I've had this car for 1yr/84k miles. It went limp on the freeway 2 mos ago and I could've caused an accident when it shut down. Would not go over 30 mps, engine light kept blinking and had knocking sound. Diagnostic code as the other recalls, Engine is same for the other recalls 2.4 Theta, oil was black and almost empty & just had oil changeI called kia corporate and they told me that they are not covering it since its not a recall. I have extended warranty but CNA National Warranty will only approve a used engine and a new one I would have to pay $3,000! I have made 2 car payments for a car that is immobile, $200+ for deductible, and $600+ for car service, this is not right at all. How can I get Kia to correct this. I do not want this car or any other kia! I cannot afford xmas this year all because I chose the wrong car maker!!
On July 4th 2023, I was driving with my son in car, when unexpectedly the check engine light came on and car lost power. We were on a highway with a 65mph speed limit. I was able to pull over to side of road. Car did Start back up, however was missing and misfiring. Shaking especially under acceleration. My engine has been consuming oil for many thousands of miles, it is documented; however only an oil consumption test was performed. Hyuandai and Kia has serious engine issues and they know it. This could've been worse. Luckily I still had some brake pressure to get off the road. With this stalling on the highway, it is very dangerous.
The vehicles 7-speed dual clutch transmission (DCT), is horribly jerky at very low speeds and on take off. It has become dangerous to drive as my wife almost caused an accident from the vehicle not reacting to acceleration pedal, or from it reacting completely unexpectedly. The transmission is very jerky as you take the foot off the brake without pressing accelerator pedal, it shakes the entire vehicle. It also jerks heavily if you barely touch the gas pedal on take off. Dealership has done a software update on the transmission which only helped initially for about 2-3 weeks, after which the transmission started behaving in that way much worse. It is a constant and persistent issue, however, as there are no fault codes or check engine light is not displayed, the dealer states there is nothing they can do to fix the problem. The vehicle is under full manufacturer power train warranty, yet they refuse to fix it.
2020 kia optima caught on fire in gallipolis ohio after insurance paid to fix car it continues to leak oil stall and is dangerous to drive12/24/2022
Showing 1–20 of 22 complaints
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026