Problems · by component
2020 Kia Optima engine problems
102 owner complaints to NHTSA about the 2020 Kia Optima cite engine, 68% of all 151 complaints for this model year.
Complaints
102
68% of all complaints
Crashes
1
Reported by owners
Fires
2
Reported by owners
Injuries
0
Reported by owners
What owners say about the engine
Verbatim from NHTSA complaints, newest first
“At around 103K miles, I took to the dealership for a multipoint inspection for knocking when braking and my forward collision/lane assist systems going offline mid drive. I learn I have to replace my axle, despite replacing my axle in sept 2025. I return a week after due to the red oil light blinking on randomly, and when I checked the oil myself it was dry. The braking and assumed wiring issues remained. I find out that my oil is low despite an oil change July 16th 2026. It is October 8th 2026 as I type this. I am doing an engine flush in hopes to improve oil consumption, but i have since learned that my engine may fail from these other Kia stories. I have not stalled or had engine failure yet but now I am worried about having to sell my car to avoid having to keep replacing the same flawed parts over and over, or worse injuring myself while driving it. I was hoping to take a trip but now I have to rent a car and play another 1,600 dollars for the engine flush which I have no guarantee will actually work. I am disgusted, and there should be consequences for KIA (and many other companies) for taking advantage of their customers. I need a new car now!”
“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 NHTSA 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…”
“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.”
“The oil consumption in my 2020 Kia optima is low so fast and needs to be replaced frequently. The engine is always hesitant and bucking. The car when you press the gas shakes and doesn't take off properly i have brought this up to the dealership multiple times to be told nothing is wrong. When sitting at a light idle the car shakes and the RPM's drop and rev up. When you in reverse in the car and hit the gas the whole car shakes so bed the engine feels like its go to fall out. When you drive and press the gas the engine revs all the way before the car actually finds where it needs to be. There is something wrong with the 2020 Kia Optima Engine all though nothing will be done about it even with all these complaints!!!! This has been going on for years with this car and I maintain my car had all services done...Kia doesn't want to fix the problem.”
“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.”
“I have a 2020 Optima, apparently there is a recall for the older models, yet mine is experiencing the exact same issues. Over oil consumption leading to engine failure. I have been in a rental for a month and a half due to fighting with Kia to correct the issue all while they drag their feet. Smells like another class action.”
Showing 6 of 102 reports. Read every report on NHTSA.gov.
Data from NHTSA Complaints API (owner reports, unverified) · synced Oct 28, 2026NHTSA vehicle page
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.