I’ve had my 2018 kia optima for round about two years.I only got this car because they refused to replace my previous engine on my 2015 Kia optima,even though I had a warranty but that’s another story(Kia on the Blvd).This car have given me problems from the start.Going through oil in less than a month,which they can never find a leak,not being able to go over a certain speed before I start to hear noises.Ive complained about noises,they act like they can’t hear,and said nothing is wrong with the engine when previously checked.My check engine light has came on twice and both times the car was malfunctioning on the highway resulting in me have to get a tow.First it was plugs replacement now I need a whole new engine.I really don’t know what to do at this point.I believe they sold me a faulty car
2018 Kia Optima: check engine light
39 of the 233 complaints about the 2018 Kia Optima describe check engine light.
- owner complaints
- 39
- of this car's complaints
- 17%
- typical mileage
- 99,000
- recalls
- 0
Check engine light by model year
What owners say
My teenage daughter regularly drives this vehicle. The vehicle began experiencing significant oil consumption, oil leaks, and intermittent loss of power. During an early inspection at an independent repair facility, a check engine code P1326 was identified. Due to the symptoms and diagnostic code, the repair facility advised that the vehicle could be heading toward engine failure and recommended that the vehicle be taken to an authorized dealership because potential engine issues may fall under manufacturer warranty coverage. The vehicle was then towed to an authorized dealership. During the first visit, the dealership retained the vehicle for an extended period of time, approximately two months. During that visit, several recommended services were completed, including replacement of spark plugs, ignition wires, and replacement of the valve cover gasket along with other recommended maintenance. During that visit, it was also stated that the vehicle has a known issue with excessive oil consumption. Because of this, the oil level is checked weekly and oil is added as needed. I also informed the dealership that the independent repair facility had identified code P1326, but I was told that the dealership diagnostic codes were different. After these repairs, the vehicle experienced another incident where it lost power and began idling roughly while being driven on a busy highway. The vehicle was taken back to the dealership. During that visit, it was stated that the fuel injector harness and oil pressure sensor needed to be replaced. The dealership also indicated that the spark plugs needed to be replaced again, even though they had been replaced at the same dealership less than a year earlier. At that time, I asked if the vehicle would be safe to drive for approximately one week because I needed to travel out of town and my daughter would need the vehicle. The dealership advised that it was safe to drive during that time. The vehicle was then brought back to the deal
It started with the oil. I constantly have to add oil. when it first started that’s what I was doing just adding oil. Then it got worse the engine light started to come on and it no longer gives me the low oil warning. I took it to the dealership and it was there for about three weeks. They said that the car needed a system update, they updated it and i took it home after that. Its been about a year since then and my car is still having the same issue and getting worse. I had to change the spark plugs a few times since then i also have oil coming out the back pipe and it’s been doing this since before I took it to the dealership. I also had to spend money on a rental car while it was at the dealership.
While driving my 2018 Kia Optima S, the car suddenly jerked, lost power, and stalled in traffic. Multiple warning lights came on at the same time including the oil light, battery light, and check engine light. I had no acceleration and the brakes became very hard to press. The vehicle had to be towed for safety reasons. The Kia dealership inspected the vehicle and confirmed internal engine failure due to “cylinder failure” and stated the engine needs complete replacement. This failure occurred without any external leaks and without warning other than the sudden loss of power. The dealer stated the issue is not covered, even though it is clearly an internal engine malfunction. This is a major safety hazard because the stall happened while I was in active traffic. A sudden loss of power and braking ability puts me and others at risk of an accident. The problem has been confirmed by the Kia dealership through diagnostic testing. The vehicle is still available for inspection. Warning lamps appeared only at the moment of failure, giving no advance warning. This appears to be related to the ongoing engine defects in Kia vehicles involving oil starvation, loss of compression, cylinder scoring, and internal engine failure. Cylinder failure and sudden stalling should be investigated as part of the known safety-related engine defects affecting this model.
I was driving on the highway with my children and the engine started to knock and lock up. I had to swerve onto an exit and roll into a gas station. My check engine light was on. I had it serviced in 2023 at a kia dealership. I had electrical issues to my battery that I opted to get fixed elsewhere. The dealership was aware of the recall on my engine, when I had it towed to them in 2025. Dealership said I opted out of a recall on my engine.
My 2018 Kia Optima went into limp mode while exiting the freeway. I had it scanned and received a P1326 code, which is directly tied to the known engine knock sensor / bearing wear issue in Kia models. The engine light came on and the car lost power suddenly. This created a very unsafe situation. I contacted Kia, and they confirmed that my VIN is not included in the engine recall (KSDS campaign), even though my symptoms exactly match the covered vehicles. I am now stuck with an undriveable car and no recall coverage, even though I’m facing the same failure risk. I believe this VIN should be included, and that this is a clear safety issue. I am requesting the federal safety agency to investigate and push Kia to expand coverage to include more affected vehicles.
My 2018 Kia Optima LX began using excessive oil (>3 quarts/1000 miles) just over 100K miles. I researched and found that the Theta II engine in my car is known for this. When I took my car to dealership (Stokes Hodges Kia, North Augusta, SC), with the check engine light on, they told me me plugs were fouled (they were just replaced 1 yr prior), cylinder 3 misfiring, and that I needed to pay a few thousand dollars to have repaired. When I asked them to guarantee the soaking process they recommended, they responded that they couldn't, that it "only worked 80% of the time." I have the KSDS download since 2019 and asked them to follow the guidelines of their TSB ENG 222 for the class action lawsuit and start a 1000 mile oil consumption test. they refused, basically telling me the only way to get a new engine from Kia, since my car is over 100K miles, is to drive it until the engine seizes. I expressed my fear for personal safety, but they wouldn't help me. I am original owner and have all services, etc documented. I called Kia customer affairs, then was told only local dealership could help. they stuck me in a loop between them without helping. Please help me.
Got an oil change, and they advised that it was low on oil. (I had just replaced it recently) I took it to the dealer and they advised a part was bad, that they replaced. I was driving and the check engine light and oil light came on . I had to tow car. Dealer said the engine was burning oil, and that the engine is covered, but I would have to drive it until it got worse.
Subject: Urgent Request for Engine Replacement – 2018 Kia Optima Dear Kia Consumer Affairs, I am writing to formally report a recurring and increasingly dangerous engine issue with my 2018 Kia Optima, and to request immediate assistance, including consideration for an engine replacement due to ongoing safety and reliability concerns. Since June 2024, I have routinely visited the Kia dealership on a near-monthly basis for service due to persistent problems with excessive oil consumption and spark plug failures. Each visit has resulted in service-related expenses, despite my efforts to maintain the vehicle in accordance with manufacturer recommendations. Unfortunately, the issue has not been resolved and continues to worsen. Most recently, on [XXX], I experienced a critical incident. While driving, the engine began shaking aggressively, the check engine light illuminated, and smoke was detected coming from the engine compartment. Out of concern for my safety, I immediately pulled over and had the vehicle dropped off at a nearby garage for emergency inspection. This incident, combined with the repeated monthly service visits and associated costs, clearly indicates a systemic issue that may be linked to known engine defects in similar Kia models. I urge Kia to review my case for warranty coverage, recall eligibility, or goodwill engine replacement assistance. I have attached supporting documentation including service records, receipts, and oil consumption logs. Please advise on the next steps for resolving this matter. Thank you for your attention. I look forward to your prompt response. Sincerely, [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
The contact owns a 2018 Kia Optima. The contact stated that while driving at various speeds, the contact noticed an abnormal oil consumption. The check engine warning light was intermittently illuminated. The vehicle was taken to a local dealer, where it was diagnosed with a spark plug misfire. The vehicle was repaired; however, the failure persisted. The vehicle was towed to a local independent service center, and the spark plugs were replaced. The contact stated that the vehicle was taken to a local independent mechanic where it was repaired several times; however, the failure reoccurred. The vehicle was taken to a second local independent mechanic, where the spark plugs and other unknown repairs were made. The manufacturer was made aware of the failure. The failure mileage was approximately 100,000.
The contact owns a 2018 Kia Optima. The contact stated that while driving 65 MPH, the check engine warning light illuminated, and the vehicle shuddered and stalled. The contact was able to pull over to the side of the road. The vehicle was able to restart but was shuddering significantly. The vehicle was towed to the dealer, where it was diagnosed with a fractured valve in cylinder #1. The dealer determined that the engine needed to be replaced. The vehicle was not repaired due to the cost. The manufacturer was notified of the failure and confirmed that the maintenance records of the vehicle were satisfactory; however, the manufacturer denied assistance and informed the contact that the failure was not a factory defect but was due to wear and tear. The failure mileage was approximately 109,000.
The contact owns a 2018 Kia Optima. The contact stated that while his daughter was driving at an undisclosed speed, the check engine warning light illuminated, and the vehicle went into LIMP Mode. The vehicle was towed to an independent mechanic, who related the failure to the federal safety agency Campaign Number: 17V224000 (Engine and Engine Cooling); however, the VIN was not included in the recall. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 106,000.
Service bulletins that may apply
- Voluntary emissions service campaign: theta II 2.4L GDI emissions: ECM logic improvement (SC340 revision 5)
- Voluntary emissions service campaign: owner notification (SC340 flight 104 )
- Voluntary emissions service campaign: owner notification (SC340 flight 103 / jf)
- Voluntary emissions service campaign: theta II 2.4L GDI emissions ECM logic improvement (SC340)
- Voluntary emissions service campaign: owner notification (SC340 flight 101 / jf)
- Voluntary service campaign: theta II 2.4L GDI emissions ECM logic improvement (SC340)
- Voluntary emissions service campaign: owner notification (SC340 flight 102 / jf)
- Voluntary emissions service campaign: theta II 2.4L GDI emissions ECM logic improvement (SC340)
Related recalls
No recalls on record for this model year.
Questions about the 2018 Kia Optima check engine light
Is check engine light a common problem on the 2018 Kia Optima?
39 of 233 owner complaints about the 2018 Kia Optima (17%) mention check engine light. The model year with the most reports is 2013.
Is there a recall or service bulletin for this on the 2018 Kia Optima?
There are 0 recalls and 58 service bulletins for the same area of the car. Check them below with your VIN.
Other symptoms on the 2018 Kia Optima
Oil consumption 54Engine failure 30Stalling 29Knocking 23Jerking 15Fire or smoke 13Headlights 13Misfire 11Loss of power 10Won't shift 8Hesitation 7Fuel pump 6Won't start 6
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