What 136 owners told NHTSA about the 2020 Kia Optima

My engine is burning lg amounts of oil. There has been a lawsuit regarding the same issues with Kia engines (specifically up to 2019 Optimas). The Theta 2 engine lawsuit is regarding excessive oil consumption/burning, knock sensor issues, and deeper engine issues. This has been an ongoing issue for me and is ultimately affecting my engine. Kia will not cover the defects or repair expenses despite knowing the concerns with prior Kia Optima engines.

NHTSA ODI 11685083

Without warning my car went into “Limp Mode” while driving on the highway almost causing a collision as I was forced to pull off the road on the highway. Flashing engine light car would not accelerate and was shaking dramatically. Was forced to wait for a tow on a busy highway. P1326 code. Rod knock. A known issue for the Theta II engine. Many recalls have been made for this exact engine for these exact problems but for some reason the 2020 Kia Optima is not included even though it is the same engine covered by lifetime warranty from the 2019 models due to these recalls and know issues. There’s plenty of recorded cases all over the web and is a wide concern for many affected Kia drivers. Kia does not offer the same KRDS update to 2020 Kia drivers as they do to earlier models even with the same engine failure issues so we don’t even get the benefit of possible early detection. Car is well maintained and inspected at a local American tire depot and I am still forced to deal with unwarranted engine failure on a known defective engine solely because KIA will not offer help for affected customers. The 2020 KIA Optima equipped with the Theta II 2.4L engine is not safe and is a known defective product. Action and accountability are needed.

NHTSA ODI 11684244

Car burns oil at significant rate which ruins the engine

NHTSA ODI 11684127

Every since I bought my car back in 2020 I have to keep getting a oil change because my light keep coming on I was told by a mechanic the my Kia have a oil consumption problem

NHTSA ODI 11679718

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

NHTSA ODI 11678832

Burning oil, not wanting to accelerate properly on the freeway, kia has engine in previous years having the same issue, and these 2020 and they are not trying to fix them.

NHTSA ODI 11676550

Engine knocking and stalling on interstate

NHTSA ODI 11670133

Engine failure do to excessive oil consumption. I do have records. Not able to file now. Please contact if needed Thank you

NHTSA ODI 11667144

Car consumes a lot of oil. Approximately 5 quarts per week-faulty engine parts allowing oil to seep into the combustion chamber. The oil is then ignited along with the fuel, creating blue-tinted exhaust smoke. It is burning out spark plugs which is then wearing them out and almost caused car accident when car started sputtering and would not barely go once pressing gas. Has been inspected by KIA dealership. Was told engine needs to be replaced-warranty expired and nothing can be done. Car only 2 years old when this problem started and they will not replace.

NHTSA ODI 11665785

by the time i’m due for an oil change the car has no oil. there is no leak and no smoke to show car is burning oil

NHTSA ODI 11664106

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.

NHTSA ODI 11663266

engine's knock sensor

NHTSA ODI 11662323

I bought my car brand new in July of 2020. In Spetember of 2023 roughly around 60,000 miles the engine started consuming large amounts of oil. The dealership put me through the so-called warranty process 3x over a years' time. They refused to file warranty paperwork within the year I was going through the process. I have documentation clearly showing the engine burning 2 qtrs. every 1000 miles. I still have a car that I am paying on that needs a new engine that should have been replaced under warranty, but KIA failed to honor the warranty. I have been left stranded on the side of the road multiple times with my 3 children needing oil. Not to mention the car will lock by itself with it running and no one in the car. The screen where the radio is will just go blank.

NHTSA ODI 11661481

UNKNOWN, Engine excessively burns oil and is now seized. Kia used the same engine in this car as they did in the 2016-19 Models which were recalled for engine failure, however mine was not included. 2.4 Theda Engine.

NHTSA ODI 11660698

I was driving down the interstate and all of a sudden the blinking lights of the check engine light came on and automatically I went from 75 mph down to 63 mph and when I looked up what it was, it was the knock detection system of the 2020 Kia Optima. I could not accelerate beyond 63 mph and I fear that the engine might stall on me so I went to O’Reillys and have them check it and it says it’s the P1326 Code

NHTSA ODI 11658199

The car drives slowly and sputters because oil is burning out quickly. I have to replenish oil continuously.

NHTSA ODI 11657548

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.

NHTSA ODI 11653605

Hi, thank you for taking the time to look over my complaint. On Saturday march 22 while driving down the highway going about 75 mph, my car died. The check engine light was flashing and so was the oil light. I pulled over to the shoulder and when I tried cranking the car it sounded like a rumming noise and the car would not stay on. I had the vehicle towed to Texas Star Auto Shop. On monday march 24th i spoke with the mechanic and he said there is an internal engine problem . Since I am a 2nd owner and the car has 105,736 miles kia will not honor their extended warranty and I am left to pay out of pocket for repairs est cost 10,000+. I am now without a reliable transportation. This has left me annoyed and unhappy with the assistance from Kia.

NHTSA ODI 11651623

Dealing with sudden excessive oil consumption at 130,000 miles. Had an oil change about 2,000 miles ago and oil sensor has been going off after 1,500-2,000 miles driven. Mechanic put 3 more quarts in and a week and a half later oil sensor is going off again indicating low oil. Mechanic confined this has been a frequent problem with this engine and insists piston rings are faulty & will eventually need engine replacement.

NHTSA ODI 11651035

Same issue as the 2011-2019 recalled vehicles. (P1326)

NHTSA ODI 11647960

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.

NHTSA ODI 11647773

Oil consumption has rapidly been increasing causing the loss of several quarts of oil. Inspection by service center confirmed this is a known Kia issue and recommended a flush to help combat some of the issue. Service center did note that this issue would not fix the problem, but put off needing to replace the engine. Oil light was not flashing on the dash unless coming to a quick stop, but then would disappear. The value of these cars has resulted in quite a bit of negative equity for folks due to the theft issue. Now add on a fear of blowing an engine cause your vehicle is burning through oil like no tomorrow.

NHTSA ODI 11646384

My car is using a lot of oil and I have to change the oil every 2 thousand miles, oil light will come on and I check the oil and it shows the oil stick almost dry within 2,000 miles after having oil changed. The car will loose power and has a ticking noise in the motor. It’s frustrating to have to change the oil every 2,000 miles instead of every 3,000-5,000 miles like most vehicles.

NHTSA ODI 11645212

Vehicle Check engine light started flashing on and off, Code thrown is a P1326 and vehicle went into limp mode, shutting down power essentially going down the highway. Oil burning is excessive, and replacement of oil is at 1-2 quarts every 2 weeks. Engine is not running smoothly. No warning signs of oil burn present until oil pressure light flickers on when taking a curve or sitting on a major incline. Kia Dealership is aware of an issue with the P1326 codes and bearing wear, however, year of vehicle seems to not be included in the original lawsuit and recall/safety notice from all indications. Engine was manufactured and is the same as the 2019 engine that is included. Engine seizure is potential at highway speeds which could cause major harm or death during travel without warning.

NHTSA ODI 11644708

The contact owns a 2020 Kia Optima. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic, and the vehicle was connected to a diagnostic machine. The DTC indicated a glow relay failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 118,000.

NHTSA ODI 11643407