Problems · by component
2016 Kia Optima fuel/propulsion system problems
53 owner complaints to NHTSA about the 2016 Kia Optima cite fuel/propulsion system, 7% of all 760 complaints for this model year.
Complaints
53
7% of all complaints
Crashes
0
Reported by owners
Fires
6
Reported by owners
Injuries
1
Reported by owners
What owners say about the fuel/propulsion system
Verbatim from NHTSA complaints, newest first
“My 2016 Kia Optima equipped with the 2.4L DOHC I4 GDI engine began to experience progressive and severe oil consumption during the latter part of my ownership. The oil warning light began activating repeatedly, even after shortly getting the oil changed. Several certified mechanics and oil change service stations told me this was an ongoing issue with this car and engine and that there was nothing I could do but monitor it and keep it filled. At their instruction, I monitored and had it changed more frequently, often topping it off at the oil change station and at home when needed. Approximately 2 weeks after an oil change upon putting the car in reverse it started to shake uncontrollably. The car was towed to a mechanic who stated I needed an engine. I then towed it to an authorized Kia franchise dealership where the technician documented the oil consumption complaint, confirmed a Cylinder 2 misfire code, performed a borescope inspection, and found the Cylinder 2 exhaust valve burnt with a chunk missing. Engine replacement was recommended by the Kia dealership technician. Prior to my purchase, the engine had already been replaced at approximately 80,000 miles…”
“The car returned P1326 and had multiple misfires and audible knocking, the dealers will indeed fight the already existing class action warranties. Was sent home and told to “drive the fuck out of it”, to which the car did not make it home and blew gasoline into my cabin while driving on the highway. Almost passed out, and am still fighting Kia to actually address the defective rod bearings. I personally would fight tooth and nail over a 5 dollar problem, but this is something they do nationwide and can cause serious injury or death. If it weren’t a 200 LB man driving the gasoline shooting into the cabin would absolutely cause a knockout. To the time of this report they are still trying to disregard the rod bearing issue and send me home with fixes to problems caused consequentially.”
“While driving, the vehicle suddenly developed a loud knocking noise from the engine. Within one block the vehicle began smoking heavily from under the hood. I pulled over, opened the hood, and flames were visible. This is a 2016 Kia Optima with the 2.4L Theta II engine. Approximately one year ago the original engine seized and was replaced by a Kia dealer under the Theta II engine recall (SC172/SC147) and class-action settlement. This is the second catastrophic failure of a Theta II engine in this vehicle. The replacement engine has now failed in the exact same manner as the thousands of other documented cases — rod bearing failure leading to knocking, overheating, and engine compartment fire. The dealership (Fowler Kia of Windsor, CO) inspected the vehicle and quoted over $6,000 in repairs (melted engine wiring harness, ECM connector, battery cables, airbox, intake boot, etc.) while claiming the fire was “unknown cause/not the engine,” despite the clear knocking immediately preceding the fire. Kia Consumer Affairs has an open case but has not yet resolved coverage. This is a known, ongoing safety defect covered under multiple NHTSA investigations (PE21004,…”
“The car is burning oil rapidly causing potential issues with the transmission and engine. The oil burns and does not leak after a few hundred miles and has to be refilled continuously causing alot of money and potential issues with other components of the car. I notice jerking when accelerating and smoke if dont fill every 1 to 2 weeks.”
“I am filing this complaint to urgently bring attention to a serious safety and mechanical defect with my Kia vehicle's engine and fuel system. My engine is excessively consuming oil, to the point where it poses a significant risk of engine failure, which could result in a loss of power while driving and create a hazardous situation on the road. Details: I consistently have to add 5 quarts of oil approximately every month. During regular oil changes, there is barely any oil recovered from the engine, suggesting the oil is being consumed or burned internally. I took the vehicle to AutoZone for diagnostics, and they confirmed the engine is burning oil. They also mentioned it could be related to a rod or piston ring issue. There are no visible leaks under the vehicle, and the oil is not being expelled externally—it's being consumed by the engine. This issue is not normal wear and tear. It's a systemic engine defect that is causing rapid oil loss and is likely to lead to engine seizure or failure if not addressed. This level of oil consumption is not just expensive—it is dangerous. A sudden loss of engine power could cause an accident, especially at highway speeds.…”
“Driving down the road trying to accelerate. My rpm's wouldn't go over 2000. The engine started fluttering and the accelerator stopped working. Went to take to local repair shop and they stated it was an issue with the engine. problem listed after a scan: OBD P1326 Recall NUMBER: PI1802W/X (Rev 2, 01/28/2019) With this stated. My vehicle under the same Year, Model, Engine, and Production Date are all calling for a recall but my VIN doesn't have a recall. So I am wanting to enquire why my vehicle doesn't have this recall.”
Showing 6 of 53 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.