2015 Kia Optima: excessive oil consumption

Filed Aug 20, 2026 · Engine · 123,000 miles · TX

The contact owns a 2015 Kia Optima. The contact stated that for over 8 years, the vehicle was experiencing excessive oil consumption. There was no warning light illuminated. The contact became aware that there was an oil leak on the ground underneath the vehicle. The vehicle was taken to the dealer on several occasions for the oil consumption failure; however, the dealer was unable to find a fault with the vehicle. The dealer had not yet provided a cause for the oil leak. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 123,000.

Filed Feb 13, 2026 · Engine, Transmission · CA

On December 27, 2025, at approximately 150,556 miles, my 2015 Kia Optima Hybrid experienced sudden engine knocking, power loss, and failure while driving at 65 mph on a highway. The vehicle dropped into limp mode and I had to pull off the highway. The car required towing to the dealership as it would not drive safely. Diagnostics revealed a knock sensor error (P1326 code) and failing connecting rod bearings via Bearing Clearance Test, consistent with the known Theta II engine defect (manufacturing debris causing oil starvation and premature bearing wear). This follows earlier symptoms: Intermittent 'Check Hybrid System' warnings in early December 2025 at 148,665 miles (dealership unable to reproduce, but historical codes noted). The Knock Sensor Detection System (KSDS) software update was performed in February 2022 during prior CHS warnings. Despite onset of issues under the 150,000-mile extended warranty limit per the Kia E2 Settlement, Kia denied coverage due to the minor mileage overage and directed me in a loop between Consumer Assistance and the Settlement Administrator. The defect poses a serious safety risk: potential for sudden engine seizure, stalling while driving, or engine compartment fire (as seen in related Theta II recalls and thousands of the federal safety agency complaints). No crash, injury, or fire occurred in my case, but the failure left the vehicle undrivable and unsafe on the road. I have service records and diagnostic reports to support this.

Filed Dec 2, 2025 · Engine, Fuel system · NV

12-01-2025 driving to work in the morning approx 7:00A.M. and turned on the heater and had a very strong smell like fuel so immediately turned it off. Cracked my windows to air it out and then was super cold again and had turned on the heater to try again. Immediately had to turn it off and rolled windows down to air it out because the smell was intense and had started to feel nauseas. Later in the day, about to head to lunch and had started the vehicle and smelt a lot like gas and turned it off and had someone come out to double check the smell. Co worker had strong smell from the hood area and looked underneath the car and can see a little drop puddle. Opened the hood and lifted the cover to engine where you can see the leakage coming from the center hose and spill puddle. Service tech came to take a look and advised its the fuel feed to the high pressure pump. This is a safety concern because fuel is extremely flammable and can put myself in dangerous situation of firing igniting in the car or hurt others around. No check engine light and prior the vehicle incident car has been consuming oil putting in about 1- quart a week or so with commute miles about 270 weekly.

Filed Jun 10, 2025 · Engine · AL

As I was driving going at a rate of 40 MPH my engine shut off. I was able to pull to the side of the road without an accident thankfully. Cranked the vehicle back up and then the same thing it happened again. No check engine light came on either time. Drove for another 200 miles no issues. Going apx. 75 MPH it went into limp mode and check engine light came on and the P1326 code appeared. There is a recall on this vehicle for this code. However the dealership states it’s a knock sensor needing to be replaced and I will have to cover that. The same knock sensor they had me update in 2018 under there advisory. The motor burns apx. 2 quarts of oil every 3000 miles. Requires oil to be added to maintain oil level in between oil changes. Irregular mechanical noise (rattle) during cold start ups. I am scared to drive this vehicle and do not feel I am being treated fairly due to the recalls on this engine.

Filed May 20, 2025 · Engine, Transmission · CA

Vehicle experienced sudden loss of power while driving when cylinder 3 completely failed (0 PSI compression). Metal particles found in oil and excessive oil consumption (1 pint/100 miles). KIA dealer diagnosed as piston rings but ignored metal in oil that suggests bearing failure covered under recall campaign. Refused proper diagnostic testing. Vehicle now unsafe to drive with failed cylinder that could cause complete engine seizure while driving. Kia had all recommended services and oil changes since acquired in 11/2016. These service records demonstrate the progression of my vehicle's engine issues, from early oil consumption problems documented by York Auto Care in July 2023 (3 quarts low) to complete cylinder 3 failure with zero compression confirmed by Kia's own diagnostic testing in May 2025. Despite this documented history and Kia's own test results showing catastrophic engine failure, they have denied warranty coverage under their engine campaign that specifically covers bearing-related failures on my 2015 Kia Optima 2.4L.

Filed Apr 8, 2025 · Brakes · 87,600 miles · FL

The contact owns a 2015 Kia Optima. The contact stated that the vehicle was previously included in the federal safety agency Campaign Number: 20V519000 (Service Brakes, Hydraulic) in October of 2020. The vehicle was taken to the dealer, who tested the vehicle to determine that the vehicle was not leaking brake fluid. Approximately 5 years later the ABS, traction control, and brake light illuminated, causing the vehicle to hesitate and jerk while driving. The contact stated that there was a burning oil odor coming from the vehicle. The contact inspected the vehicle and noticed the modulator valve was leaking oil, causing it to leak out of the vehicle when the cap was removed. The contact noticed oil on the skid plate underneath the oil pan. The vehicle was towed to the dealer, who diagnosed that the ABS module needed to be replaced. The vehicle was repaired. The manufacturer was informed of the failure and opened a case. The manufacturer referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 87,600.

Filed Jan 2, 2025 · Engine · 88,000 miles · VA

The contact owns a 2015 Kia Optima. The contact stated that the vehicle was taken to a local dealer and was repaired for excessive oil consumption. The contact stated that the vehicle was repaired at the local dealer under an unidentified the federal safety agency recall; however, the repair failed to prevent a failure from occurring. The contact stated that while her husband was driving at an undisclosed speed, the vehicle lost automotive power, and the engine seized. The vehicle was towed back to the same local dealer, but the vehicle was not repaired due to the maintenance records not being available. The vehicle was left at the local dealer for further investigation. The manufacturer was made aware of the failure. The failure mileage was approximately 88,000.

Filed Jul 23, 2024 · Electrical · GA

I was driving on the expressway onto the exit ramp going about 75 mph when my car suddenly slowed down even though my foot was on the pedal as i kept trying to drive, it was slowing down. The temp gauge was exactly in the middle and the rpm was at 0. The mph was at 60 mph even though it was slowing down it didnt change on the reader. When i realized the mph on the reader was not changing all the service lights came out on the dash. So I idled to a stop on the side of the road when I got out of the car I realized there was smoke coming from the hood and it had a really awful smell of something burning. I know the engine didnt over heat because the coolant reservoir is full and the upper radiator hose had pressure. Ive been having an issue with burning oil so I topped it off with a qt of oil. I left the car off for about 2 hours and then tried to start it and the engine would not start , the break pedal became hard to push down but the burning smell got worse. So i decided to turn the car off again. Meanwhile im still stuck on the side of the road. I watched a couple of youtube videos and there are many people having the same issue with the radiator fan, or a leak in a pipe or hose, or some sort of sensor.

Filed Apr 24, 2024 · Engine · OH

The contact owns a 2015 Kia Optima. The contact stated that while driving 30 MPH, there was an abnormal smoke odor inside the interior of the vehicle. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who determined that there was an oil leak in the engine compartment. The vehicle was not repaired. The vehicle was then taken to the dealer, who diagnosed a failure with the engine, determining that the engine was consuming oil abnormally quick, and the engine might soon need to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure but provided no assistance. The failure mileage was unknown.

Filed Mar 27, 2024 · Engine · WA

Loss of power to engine when trying to increase speed to turn into traffic/getting onto the highway and constant severe engine knocking noise. I have to use hazards when turning into traffic/merging onto highway because the vehicle takes too long to catch up with the speed of traffic. It also has a problem with excess oil consumption, needs to be refilled every week and a half to two weeks. Bremerton Transmission has provided an inspection and a Diagnostic Trouble Code (DTC) P1326 (Knock Signal Range/Performance). The oil consumption has been an ongoing issue since I bought the car in February of 2022, only getting worse. The rest of the issues have been escalating problems.

Filed Jan 13, 2024 · Electrical, Engine · FL

I purchased my car in 2015 at 23k miles, now we're at 86k miles and I'm experiencing issues. How is there a recall for this car but no remedy yet when there is a high risk of fire? Shouldn't there be a resolution for this safety concern? I noticed my car in 2022 would smoke here and there when driving, and I would smell burning. I took it to my mechanic and he changed the head gasket, and the smoking stopped. There is residue on my engine from a leak from the oil. My mechanic at the time told me I might still smell burning oil just due to that. As time went on things were fine but a year later, the oil smell came back stronger. I notice it only on longer drives, so I do believe my car is leaking oil. Also, the amount of time I've changed my break lights this year and head lights. They dim so fast over time and eventually go out to where I have to replace them. There is 100% an electrical issue going on.

Filed Dec 22, 2023 · Engine · 81,000 miles · GA

The contact owns a 2015 Kia Optima. The contact stated while driving 20 MPH, the vehicle inadvertently lost motive power. The contact pulled over to the shoulder of the roadway, where the vehicle failed to restart. The check engine and low engine oil warning lights were illuminated. The vehicle was towed to an independent mechanic, who determined that an unknown fluid had leak and damaged the electrical components in the engine compartment, causing the engine to seize. The vehicle was not repaired. The manufacturer was notified of the failure but referred the contact to the federal safety agency hotline for assistance. The approximate failure mileage was 81,000.