2020 Kia Optima: sudden loss of power

Filed Oct 28, 2026 · Engine · NC

On October 25, 2026, while traveling eastbound on US Highway 74 near Bryson City, North Carolina, my 2020 Kia Optima 2.4L GDI experienced a sudden and substantial loss of engine power while driving through mountainous terrain. The check-engine light began flashing, and the vehicle entered what appeared to be reduced-power or limp mode. The engine remained running, but acceleration and available engine power were significantly reduced. This created a serious safety concern due to the mountainous highway conditions and surrounding traffic. I immediately pulled over at the first safe opportunity and did not continue driving the vehicle. My partner, who was approximately six months pregnant, was traveling with me. We remained stranded along the roadside for approximately three hours awaiting assistance, approximately 202 miles from home. Diagnostic trouble code P1326 was subsequently identified. There were no noticeable knocking, rattling, or ticking noises before or after the incident. The oil-pressure warning light did not illuminate. After the incident, the engine oil level was checked and found to be between the minimum and maximum dipstick markings. Timestamped photographs were taken during the towing process and at dealership drop-off. The vehicle was transported to a Kia dealership, where a bearing clearance test was performed and passed. The dealership also identified an external oil leak. However, the cause of the sudden loss of power and P1326 activation has not been conclusively established. I am reporting this incident because the unexpected and substantial loss of engine power while driving on a mountainous highway created a potentially dangerous situation. I am concerned that the condition could recur and pose a safety risk to other drivers and passengers.

Filed Oct 1, 2026 · Engine · GA

purchased this vehicle on June 18, 2024, as a second owner with 125,019 miles on the odometer. Within months of purchase, the engine began exhibiting symptoms consistent with connecting rod bearing failure: engine knock, excessive oil burning (requiring oil top-ups every 2-3 weeks), and rough running. The check engine light illuminated with diagnostic code P1326 (Knock Sensor Detection System warning). I took the vehicle to Kia Stonecrest dealership for diagnosis. Kia informed me that the engine failure is not covered under warranty because I am not the original owner. A independent mechanic at Lions Auto evaluated the engine and quoted $4,800 for full engine replacement. THE DEFECT: This vehicle is equipped with a Theta II 2.4L GDI engine identical to engines in 2011-2019 Kia Optimas and Kia Sorento models that were subject to multiple recalls (including the federal safety agency Recall 17V‑224) and a $1.3 billion class action settlement. The defect is manufacturing debris left in the crankshaft oil passages during production, which restricts oil flow to connecting rod bearings, causing premature bearing wear, engine seizure, and potential engine fire. KIAS KNOWLEDGE AND RESPONSIBILITY: Kia had clear notice of this defect years before the 2020 model year was introduced. Despite this knowledge, Kia continued manufacturing 2020 and later Optimas with the identical Theta II 2.4L GDI engine without remedying the manufacturing process. The class action settlement litigation was filed in 2017 and covered model years through 2019; however, Kia’s decision to exclude 2020 models from coverage despite using the same defective engine creates an unjust gap in consumer protection. SAFETY CONCERN: Connecting rod bearing failure can cause sudden engine seizure while driving, resulting in loss of power steering and brake assist, creating an immediate crash hazard. The symptoms I experienced — engine knock and P1326 code — are documented precursors to catastrophic failure.

Filed Sep 22, 2026 · Engine, Transmission · TX

While driving to work, my 2020 Kia Optima suddenly lost engine power and went into limp mode in the middle of the highway, leaving me stranded and creating a severe safety hazard in traffic. The check engine light immediately started flashing and displaying diagnostic code P1326 which indicates an abnormal engine and/or a catastrophic rod bearing failure. This problem has been confirmed by the Kia dealership along with a 3rd party auto repair shop. However, Kia is refusing to cover the inspection, diagnostic, or any repairs due to the vehicle not having any open recalls, having more than 100k miles and the model of my vehicle despite this being a well known and documented manufacturing defect issue to these engines. The vehicle is currently available for inspection.

Filed Sep 8, 2026 · Engine, Transmission · TX

While driving, my 2020 Kia Optima suddenly lost engine power and went into limp mode on the road, leaving me stranded and creating a severe safety hazard in traffic. The vehicle threw diagnostic trouble code P1326, which indicates a catastrophic rod bearing failure. The problem has been confirmed by a Kia dealership scanner. However, both the dealership and Kia America are refusing to cover the inspection and repair under their safety campaigns or goodwill due to the vehicle having 180,000 miles, despite this being a well-documented manufacturing defect inherent to these engines. Prior to the failure, the check engine light started flashing. The vehicle is currently available for inspection.

Filed Apr 6, 2026 · Engine · KY

The rod barring failed in my engine. I broke down in the middle of the parkway with my daughter. This is my third Kia optima that has had this issue but the dealership is stating there is not a recall on this model. The check engine light did not come on except when the car lost all power.

Filed Jan 8, 2026 · Engine · GA

While driving, the vehicle experienced a sudden loss of engine power and entered limp mode. The check engine light began flashing and the vehicle had very limited acceleration, creating a safety concern when driving in traffic. The vehicle was towed to a Kia dealership for diagnosis. The dealer retrieved diagnostic trouble code P1326 (Knock Sensor Detection System – range/performance). During inspection, the dealer found metal contamination in the engine oil and oil control valves and advised that the engine has internal damage and requires replacement.

Filed Dec 16, 2025 · Engine · NM

Vechile is burning oil and knock sensor came on which indicated rod bearing. While driving the car lost power the check engine came on was abl to pull over and turned off the car. Did not drive it was tow home.

Filed Nov 17, 2025 · Acceleration, Engine · WA

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.

Filed Aug 15, 2025 · Fuel system · AZ

I own a 2020 Kia Optima. My vehicle has experienced repeated low-pressure fuel pump failures, causing hard starting, loss of power, and stalling risk. These issues first appeared in July 2023 and have recurred despite multiple repairs. The dealership has replaced the upper portion of the fuel pump three times (July 10, 2023; March 1, 2025; June 9, 2025) for the same issue, but the problem persists. Most recently, in August 2025, the vehicle again exhibited difficulty starting and loss of power. Diagnostic code P123300 was found, indicating the pump is not generating enough pressure. The dealership confirmed the entire fuel pump assembly needs replacement. This is a serious safety concern because the vehicle has gone into limp mode three times while driving — twice previously on the freeway, and again on [XXX]. On that date, I experienced sudden loss of power while driving, but I had a scheduled oil change on July 29, 2025 so I waited until then to bring the car in. At that visit, the dealership claimed the problem was only an old code P0456 and that my car needed a software update. However, the very next day, my vehicle went into limp mode yet again, creating another hazardous driving situation. My check engine light has repeatedly illuminated, and each failure matches the conditions described in Kia’s extended warranty program (WTY028) for low-pressure fuel pump failures on my model year. The warranty extension letter (WTY028) for my vehicle states that “repairs related to low-pressure fuel pump failure” are covered for 15 years/150,000 miles. It does not state that only the upper portion of the pump is covered. However, my dealership (Sands Kia Surprise) insists that Kia will only cover the upper portion, even though my issue requires replacement of the entire fuel pump assembly to correct the failure. This repeated failure creates a dangerous driving condition and appears to be part of a larger defect affecting this model’s fuel delivery system. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION

Filed Aug 6, 2025 · Engine, Transmission · OH

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

Filed Dec 6, 2024 · Engine · GA

Driving at highway speed of 65 mph, the vehicle abruptly lost power. The check engine light started flashing. I was almost rear ended due to the loss of power, I was able to coast to the emergency shoulder and stop. The car was towed to the nearest Kia dealership. Diagnostics show code P1326, the engine has failed and needs to be replaced at a cost of over $10000. This the same engine that was included in a class action lawsuit for model years up to 2019, the 2020 was not included. Kia is offering no assistance to me as the second owner of the vehicle even thought the car only has 98,000 miles, the powertrain warranty is reduced to 60,000 for a second owner. The cost of repairs is more than the value of the vehicle.

Filed Oct 13, 2024 · Acceleration, Engine · CA

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.