Kia Optima check engine light comes on

Filed Nov 3, 2026 · Acceleration, Engine · MI

I have a 2019 Kia Optima S with the 2.4L engine and 117,000 miles. The vehicle has diagnostic codes P1326 and POOOB. The check-engine light is continuously flashing, the engine is knocking, and the vehicle has lost acceleration and will not go over approximately 65 mph. I believe this may be related to the KSDS connecting-rod bearing issue under Kia campaign PI1805.

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 23, 2026 · Engine · NC

There is a known issue with this vehicle and the fix by KIA is not safe nor fair to the consumer. Kia's knock sensor recall centers on the Knock Sensor Detection System (KSDS) software update for Theta II GDI engines. The update listens for rod bearing wear, triggers a check engine light and limp mode via Code P1326, and extends the engine warranty up to a lifetime or 15 years/150,000 miles. My problem is that we had to car in on May of 2026 after in went into limp mode. They updated the software. The car again went into limp mode on 10/21/2026, they updated the software again. My focus here is the fact that it is a known issue and they say it still does not meet the parameters for an engine replacement. It is a severe issue that is dangerous and inconvenient to the driver. You are afraid to take it on a trip or even take it on a highway. My 20 year old daughter drives this to college. Can you imagine a car going into limp mode on a majory US highway? Limp mode essentially does not allow a vehicle to go above 2K RPM. You cant go up a hill over 35 and on a highway, on a flat road you "might" be able to go 55 MPH. My daughter goes to college 4 hours away. This creates a very unsafe, dangerous and inconvenient environment. KIA is hoping that they can buy time until these vehicles fail for some other reason and they dont have to pay the cost for a new engine.... ALL at the consumers peril. To put this in perspective, if you have a vehicle with a "low tire pressure" warning, does lowering the sensors parameters fix the problem.... No, it just turns off the warning and you are driving a car with low tire pressure.

Filed Oct 22, 2026 · Engine · 125,055 miles · FL

The contact owns a 2013 Kia Optima. While driving at 65 MPH, the vehicle lost motive power but continued to drive under reduced power, with the check engine warning light illuminated. The failure nearly caused a crash. The vehicle was taken to O'Reilly's, where three knock sensor codes were retrieved. The vehicle was then taken to the dealer and was repaired under the federal safety agency Campaign Numbers: 23V652000 (Service Brake, Hydraulic), 22V093000 (Fuel System, Gasoline), and 22V560000 (Structure). The manufacturer was notified of the failure by phone. The failure mileage was approximately 125,055.

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 29, 2026 · Engine · AR

The vehicle experienced a sudden and severe loss of engine power while being driven on the interstate at highway speeds. The vehicle lost the ability to accelerate normally beyond approximately 60 mph, the Check Engine Light began flashing rapidly, and the vehicle entered “Limp Home Mode.” This sudden loss of power occurred in heavy traffic and created an immediate risk of a high-speed rear-end collision. The vehicle was subsequently inspected by an authorized Kia dealership service center. Diagnostic testing confirmed DTC P1326 (Knock Sensor Detection System). The dealership performed the manufacturer’s Bearing Clearance Test (BCT), and the dealership paperwork documents a “NO PASS BCT” result. The dealership paperwork also documents that Service Campaign SC340 (Theta II 2.4L GDI ECM Software Upgrade) was performed on the vehicle. Despite the documented P1326 condition and the manufacturer’s “NO PASS BCT” result, the dealership is refusing to provide the engine replacement as a covered repair and has instead quoted approximately $9,000 for the engine replacement. I am requesting that the federal safety agency review this matter because the vehicle experienced a sudden loss of power at highway speeds, followed by a documented “NO PASS BCT” result from the manufacturer’s diagnostic procedure. The vehicle remains an unresolved safety concern. I am also requesting review of whether Kia is properly applying the applicable P1326/BCT engine-replacement procedure and associated coverage to this vehicle. The vehicle and all diagnostic and service paperwork are available for inspection upon request.

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 15, 2026 · Fuel system · FL

My vehicles Low-Pressure Fuel Feed Tube disconnected from the engine and sprayed fuel over the top. The vehicle was running and the engine was hot but luckily there was no fire and no was injured, but if this had happened any sooner it could have been much worse. There is currently a recall for this part on my exact model car and year, but my VIN does not show the recall. The part was inspected by a mechanic who informed me this should be covered by the recall based on everything listed in the safety recall campaign. The vehicles check engine light came on just before the temperature gauge light up. after pulling over there was a clear gasoline smell in the vehicle and upon inspection the feed tube was no longer connected to the engine.

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 Jul 23, 2026 · Engine · FL

The vehicle's engine had previously been replaced once under Kia's Theta II engine recall/warranty program approximately five years prior to this incident. On the date of failure, the replacement engine catastrophically failed while the vehicle was in operation, resulting in the engine developing a hole in the engine block and becoming inoperable. Prior to the failure, the vehicle exhibited a "check engine" warning and symptoms consistent with connecting rod bearing failure. Diagnostic trouble codes P1326 and P0303 were present upon inspection at an authorized Kia dealership. The failure occurred at approximately 198,000 miles. This is the second engine failure on this vehicle, both consistent with the known Theta II engine defect involving premature bearing wear and connecting rod failure that has been the subject of prior the federal safety agency recalls and a related class action settlement. The failure created a risk of sudden loss of engine power while driving, which can pose a safety hazard in traffic. The vehicle was inspected by the authorized Kia dealership, which confirmed the hole in the engine block and the diagnostic codes noted above. The engine and related repair estimate are available for inspection upon request. A warranty claim for repair coverage was submitted and denied by the manufacturer, citing insufficient maintenance documentation, despite this being the vehicle's second occurrence of the same underlying defect.