2015 Kia Optima Problems

What owners report

Owners of this model year most often describe engine problems — oil that disappears between changes, knocking sounds, stalling and seized engines, sometimes with smoke or fire from the engine bay. Many complaints arrive well past 80,000 miles, and several owners say the dealer attributed the failure to oil consumption or lack of a prior knock-sensor software update. Other recurring themes in the sample are ABS/brake warning lights tied to the hydraulic control unit recalls, and sudden loss of power steering assist.

1. 1
   Engine

   Engine noise, stalling and seizure

   • 480 complaints (48%)
   • median 88,000 mi at 6.1 yrs old (274 state mileage)
   • 37 mention a crash, fire or injury
   • owner-quoted repair $5,500 (median of 26 quotes)
   • filed 2015–2026

   Owners describe vehicles that lose power or stall while driving, sometimes at highway speed, with the check engine light on or flashing, then fail to restart. Many say a dealer found metal in the oil or a failed bearing and recommended engine replacement; several mention the knock sensor detection system update or a prior engine replacement being checked before assistance was offered. A few complaints describe smoke from the engine bay around the time of the failure. Reported from about 51,000 to 200,000 miles, with most sampled complaints between roughly 70,000 and 150,000 miles.

   Recall 18V9070008 related service bulletins

   What to check: Ask for service records and whether the knock sensor detection system update and any engine replacement campaign were completed; check the oil level and look for a fuel or burning smell on the dipstick.

   2 excerpts from owner complaints in NHTSA records

   “I was driving on the high at at about 65 miles a hour and my car shut off completely and wouldn't start. I called a tow truck and got it towed to a Kia dealership. They got back to me about two weeks later and said my engine was blow but it was on recall but my carfax only have one oil change done since I bout the car. I provided them with up to date service records and I told them the last two oil changes I did were on my own. …”

   NHTSA complaint #11364026, filed 2020-10, 76,000 miles

   “I have a 2015 Kia Optima with 74,000 miles. As I was driving my vehicle on a city street when suddenly it started shaking and released black smoke prior to engine failure. A vehicle behind me had to brake and swerve to miss hitting me. This incident occurred on january 10, 2020. I received a diagnosis from the dealership confirming the vehicle had engine failure due to knock sensor and compression issues. Also stated that the head gasket is damaged. …”

   NHTSA complaint #11301596, filed 2020-01, 74,000 miles
2. 2
   Engine

   Oil consumption between changes

   • 129 complaints (13%)
   • median 80,000 mi at 5.1 yrs old (73 state mileage)
   • 6 mention a crash, fire or injury
   • owner-quoted repair $6,250 (median of 10 quotes)
   • filed 2016–2026

   Owners report the oil level dropping noticeably between scheduled changes, with no visible leak on the ground and a needed top-up within weeks of a change. Some describe burnt-oil smell, dark oil, white smoke from the exhaust, and mechanics finding the engine low or dry; in a few cases the low oil was followed by engine seizure. Mostly reported between roughly 44,000 and 130,000 miles, often noticed shortly after an oil change.

   4 related service bulletins

   What to check: Check the oil level and condition yourself, ask how often the owner adds oil, and ask whether an oil consumption test was ever done at a dealer.

   2 excerpts from owner complaints in NHTSA records

   “When taking off at a stop light or getting onto the interstate (basically when accelerating) the car feels like it has no power. You can hear a weird noise and sometimes you will smell burnt oil or something burnt. Also, I had a recent oil change and within the month I had to add oil again. There is no sign on my driveway that there is a leak. Please look into this as there are multiple people with the same issues.”

   NHTSA complaint #11300028, filed 2020-01, 65,000 miles

   “My Kia is using and losing oil rapidly. As in in-between oil changes. There are no leaks and it is not burning oil. My engine has seized up twice, while driving on the interstate, because its rapidly using that much oil. My mechanic says he's worked on several Kia's with this similar problem. Where is my oil going? After calling 5 Kia dealerships today, none of them can get me in for at least 45 days because they are so backed up with fixing all the recalls.”

   NHTSA complaint #11413189, filed 2021-04, 64,736 miles
3. 3
   Brakes

   ABS and brake warning lights, HECU recalls

   • 115 complaints (11%)
   • median 100,000 mi at 7.6 yrs old (61 state mileage)
   • 20 mention a crash, fire or injury
   • owner-quoted repair $2,790 (median of 6 quotes)
   • filed 2015–2026

   Owners report ABS, TPMS and check engine lights staying on, a burning smell inside the cabin, and in some cases heat near the brake pedal area or under the hood. Several complaints reference the hydraulic control unit recalls and note that the remedy part was not yet available when they contacted a dealer. Reported from about 16,000 to 231,000 miles, with several between 69,000 and 150,000 miles.

   Recall 23V652000Recall 21V331000Recall 20V519000

   What to check: Check whether recalls 23V652000, 21V331000 and 20V519000 were performed and whether the remedy part was installed; look for a persistent ABS light or burning smell.

   2 excerpts from owner complaints in NHTSA records

   “The contact owns a 2015 Kia Optima. The contact stated that while pulling into the driveway, the ABS warning light remained illuminated after the vehicle was powered off. The contact stated that the parking brake warning light unexpectedly illuminated while the vehicle was being operated. The contact stated that the brake lights illuminated while the vehicle was turned on or off. …”

   NHTSA complaint #11767775, filed 2026-09, 231,000 miles

   “The contact owns a 2015 Kia Optima. The contact received notification of NHTSA Campaign Number: 23V652000 (Service Brakes, Hydraulic) however, the part to do the recall repair was not yet available. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. …”

   NHTSA complaint #11590643, filed 2024-05, 150,000 miles
4. 4
   Engine

   Engine bay smoke or fire

   • 138 complaints (14%)
   • median 88,000 mi at 5.3 yrs old (81 state mileage)
   • 50 mention a crash, fire or injury
   • owner-quoted repair $6,250 (median of 6 quotes)
   • filed 2016–2026

   Complaints describe smoke turning black and flames appearing from under the hood while driving, sometimes preceded by knocking or a loss of power. Owners report pulling over and using an extinguisher, fire department response, and vehicles being destroyed; others describe only smoke or a burning odor with no fire. Spread across roughly 75,000 to 150,000 miles in the sample, with one report at very low mileage.

   Recall 18V907000

   What to check: Ask about any engine or fuel-system repairs and whether open recalls were completed; watch for oil or fluid smells and any smoke under the hood.

   2 excerpts from owner complaints in NHTSA records

   “I had just left the construction zone on I-30 eastbound in benton, ar. I was in the left lane when the car began acting jerky as if it was trying to accelerate. I started to cross over to the right lane when I noticed smoking coming out the back. I got on the right shoulder, parked in front of exit 118, and turned off the vehicle. …”

   NHTSA complaint #11407392, filed 2021-04, 100,000 miles

   “While driving down the highway was traveling around 65 MPH on dry street in the far left lane (fast lane), my car started making a sound like metal clicking and then car started smoking. My husband gets over to the side of road and the smoke goes from gray to black and when he lifted the hood up flames coming from rear and passenger side of engine! Luckily someone pulled over and had fire extinguisher to put out fire. Fire and police both arrived on scene and reports made. Vehicle towed home; waiting to tow to dealer to find out cause of fire. …”

   NHTSA complaint #11330210, filed 2020-06, 123,000 miles
5. 5
   Steering

   Loss of power steering assist

   • 67 complaints (7%)
   • median 57,000 mi at 5.0 yrs old (44 state mileage)
   • 8 mention a crash, fire or injury
   • filed 2014–2026

   Owners describe the steering suddenly becoming heavy along with the traction control or ABS light coming on, and the wheel being hard to turn at speed. Some also report the steering locking briefly or seizing together with a loss of power; dealers reportedly told some owners the condition was not covered by a recall. Mostly reported between about 33,000 and 96,000 miles, with a few higher-mileage reports.

   What to check: Test the steering at low and highway speeds and check that no traction control or ABS lights are on; ask whether the steering column or assist system has been serviced.

   2 excerpts from owner complaints in NHTSA records

   “About a month and a half ago my traction control light came on and I lost power steering. For a brief period of time that day the light went off and I regained power steering. Later that same day the traction control light reappeared and has been on since causing me to lose power steering. I have spoken with the manufacturer and they claim that this problem does not fall under any recall therefore they are not responsible for anything.”

   NHTSA complaint #11373549, filed 2020-11, 86,000 miles

   “While driving at speeds higher than 45 MPH, the steering wheel locks for a brief moment. This does not allow for a smooth way to keep the vehicle straight on the highway. Very scary. Antenna cover on top of car flew off on the highway. Read that it has happened to several other 2015 Optima models. Back up camera is foggy and I can no longer use it when reversing. Back taillights have condensation in them. I have already had one of them replaced early on.”

   NHTSA complaint #11317571, filed 2020-03, 44,000 miles

Buying note. Have a pre-purchase inspection check oil level and consumption history, engine noise, and whether the knock sensor update and open brake recalls were completed. Service records matter more than usual on this model year, since several reported engine problems were handled case by case at the dealer.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.