Kia Optima loss of power problems

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 Nov 5, 2026 · Engine · AZ

My Kia experienced catastrophic engine failure while I was driving on the freeway, creating an extremely frightening and dangerous situation. The sudden loss of engine power put my safety and the safety of surrounding motorists at risk, as I was traveling at freeway speeds when the engine gave out. Leading up to the failure, my vehicle experienced excessive oil consumption despite regular maintenance. I was repeatedly adding oil between scheduled oil changes. Previous repairs, including replacement of spark plugs and a thermostat, did not resolve the underlying issue. Following the engine failure, a Kia dealership reported a cracked engine valve and multiple severely damaged or melted spark plugs, including spark plugs that had recently been replaced. These findings raise serious concerns about progressive internal engine damage and a potentially defective engine. Despite my concerns regarding known Kia engine defects and possible connecting rod bearing issues, the dealership stated it could not perform the bearing clearance test due to the condition of the valves. My case was never submitted to Kia Techline for further investigation. I was initially instructed to provide oil change and maintenance records for consideration of engine replacement assistance, only to later be told that excessive oil consumption was not relevant to my claim. I am extremely concerned that a potentially defective engine experienced progressive damage before suddenly failing on the freeway, placing my life and others at risk. I am requesting that the federal safety agency investigate this failure and determine whether it is related to known Kia engine defects or an unresolved safety issue affecting other vehicles.

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 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 10, 2026 · Engine, Transmission · TX

Severe engine defect (Theta II 2.4L GDI). Sudden total loss of power, metallic knocking, severe oil consumption, and imminent catastrophic failure while driving, creating a high safety risk. Vehicle is currently out of service in [XXX]. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 7, 2026 · Engine · 77,500 miles · CA

The contact owns a 2011 Kia Optima. The contact stated that while a family member was driving and exiting a parking lot, the vehicle turned off, causing the vehicle to lose power. The contact stated that there was a burning odor inside the cabin of the vehicle with an audible clicking sound coming from the starter motor. The vehicle was towed to a local authorized dealer. The contact referenced the federal safety agency Campaign Number: 17V224000 (Engine and Engine Cooling) and Kia Warranty Bulletin 2017-09.R4 as the possible causes for the failure. The manufacturer was notified of the failure but refused to accept or authorize the recall repair because the vehicle had a salvage title. The authorized dealer also declined to service the vehicle due to the salvage title. The failure mileage was 77,500.

Filed Oct 7, 2026 · Engine, Fuel system · MO

Despite documenting this catastrophic internal mechanical destruction, the authorized franchise dealer has issued a written directive instructing the driver to operate this structurally compromised vehicle on public roads for a 1,000-mile oil consumption test with explicit instructions not to add, check, or have anyone service the engine oil level. Operating an engine running dry with verified cylinder wall gouging and unstable timing chains creates an imminent, severe safety hazard for the occupants and other motorists, including sudden highway engine lockup, loss of power steering, or vehicle fires. The vehicle underwent Safety Recall Campaign SC147 in 2017, which carries a court-mandated Lifetime Warranty Extension on the block for core failures. The dealership is forcing an unsafe vehicle modification and dangerous roadway test to evade standard warranty coverage processing. A complete 11-invoice history proves this defect originally manifested and was logged by a technician at 96,738 miles while fully inside the standard factory coverage window.

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.