2018 Kia Optima problems, complaints & recalls
Most-reported problem areas: Engine (93) · Power Train (13) · Steering (11)
🧭 Reliability snapshot
Compared against other Kia Optima model years — complaint volume vs the model's median year, recalls and severity. How we score →
🛣️ Complaints by mileage
73 NHTSA complaints that reported an odometer reading.
Safety recalls (2)
Latches/Locks/Linkages:trunk Lid:latch 2023-08-24 · campaign 23V594000 · 319,436 vehicles
Defect: Kia America, Inc. (Kia) is recalling certain 2016-2017 Rio, 2016-2018 Optima, 2017-2018 Optima Hybrid and Optima Plug-in Hybrid vehicles. The trunk latch base may crack, preventing the opening of the trunk from the inside. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 401, "Internal Trunk Release."
Risk: A person inside the trunk compartment may become trapped, increasing their risk of injury.
Fix: Dealers will replace the trunk latch base subassembly, free of charge. Owner notification letters were mailed October 19, 2023. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC278.
Hybrid Propulsion System 2018-03-08 · campaign 18V161000 · 1,710 vehicles
Defect: Kia Motors America (Kia) is recalling certain 2017-2018 Kia Optima hybrid vehicles. These vehicles are equipped with a Voltage Protection Device (VPD), designed to protect the high voltage battery module, that may activate inadvertently.
Risk: If the VPD activates while the vehicle is being operated in Electric Vehicle (EV) mode, there may be a loss of power, increasing the risk of a crash.
Fix: Kia will notify owners, and dealers will remove the VPD switch and install two newly designed Battery Management Systems (BMS) that contain Overvoltage Protection Devices (OPDs), free of charge. The recall is expected to begin May 2018. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC162.
Service bulletins (155)
Technical service bulletins are repair instructions manufacturers send dealers for known issues. Unlike recalls, the fix is not automatically free — but naming the bulletin at the service desk can save diagnosis time and support goodwill repairs.
Structure:body 2026-06-08 · CS2312_TSB_R2 · Service Bulletin/Repair Instructions
technical service bulletin: customer satisfaction: theft deterrent ignition cylinder protector and decal installation (cs2312) - this bulletin has been revised to include additional information. new/revised sections of this bulletin are indicated by a black bar in the margin area. this bulletin prov
Engine 2026-04-04 · SC340_TSB_R5 · Emissions
voluntary emissions service campaign: theta ii 2.4l gdi emissions: ecm logic improvement (sc340 revision 5) - this bulletin has been revised to include additional information. new/revised sections of this bulletin are indicated by a black bar in the margin area. this bulletin provides information to
Engine 2026-03-17 · SC340_OWNR_JF&JFA_104 · Emissions
voluntary emissions service campaign: owner notification (sc340 flight 104 ) - this document is the owner notification advising that kia is conducting a voluntary emissions service campaign to improve the emissions software logic in the electronic control module (ecm) for certain 2016-2020 my optima
Engine 2026-03-06 · SC340_TSB_R4 · Emissions
technical service bulletin: voluntary emissions service campaign: theta ii 2.4l gdi emission secm logic improvement (sc340 rev 4) - this bulletin has been revised to include additional information. new/revised sections of this bulletin are indicated by a black bar in the margin area. this bulletin p
Structure:body 2026-02-19 · TSB_CS2312_R1 · Service Bulletin/Repair Instructions
technical service bulletin: customer satisfaction: theft deterrent ignition cylinder protector and decal installation (cs2312) - this bulletin has been revised to include additional information. new/revised sections of this bulletin are indicated by a black bar in the margin area. this bulletin prov
Engine 2025-12-19 · SC340_OWNR_JF103 · Emissions
voluntary emissions service campaign: owner notification (sc340 flight 103 / jf) - this document is the owner notification advising that kia is conducting a voluntary emissions service campaign to improve the emissions software logic in the electronic control module (ecm) for certain 2016-2020 my op
Showing the 6 most recent of 155 bulletins. Search all of them free at nhtsa.gov.
What owners report
2026-10-21 · Unknown Or Other“my 2018 kia optima has the theta ii 2.4l engine. in february 2026, the dealer performed an engine/powertrain computer reprogramming. in august 2026, the engine failed and the vehicle was taken to an authorized kia dealer, where the engine was replaced under the theta ii engine warranty. the vehicle was at the dealer from august 8 until the repair w…”
2026-09-08 · Engine · 126,000 mi“the contact owns a 2018 kia optima. the contact stated that upon starting the vehicle, the vehicle jerked abnormally. the failure persisted while driving, and the vehicle lost motive power. the contact was able to restart the vehicle; however, the failure persisted while driving. the vehicle was towed to a dealer to be repaired under an unknown rec…”
2026-08-20 · Engine · 136,000 mi“the contact owns a 2018 kia optima. the contact stated that while driving at an undisclosed speed, the vehicle failed to accelerate and failed to exceed 52 mph. the vehicle shut off. the contact stated that the engine was running rough while stationary and the vehicle shut off without warning. the vehicle was taken to an auto parts store, where it …”
2026-07-22 · Engine And Engine Cooling“see attached document for complaint.…”
2026-07-19 · Seat Belts · 💥 crash“i was run off the road by a drunk driver i hit a tree at 35mph my air bags did not deploy nor did my seat belt lock!!!! i now have multiple injuries i have broken bones all throughout my face!!!!! a severe concussion!!!!! any time i call the the customer care center and try and get information or call someone i either get hung up or gave the run ar…”
2026-07-09 · Engine“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 abl…”
2026-07-02 · Service Brakes“purchased vehicle from a used car dealership. had it a few months before brake pedal started losing pressure and going to floor. had master cylinder replaced. a few months later, brake light started coming on when accelerating. new master cylinder had leaked into brake booster. had master cylinder replaced along with brake booster. a few weeks late…”
2026-06-25 · Engine“the car burns oil within a week of getting an oil change. it was only driven a 200 miles before all of the oil was burned out. this has been a consistent issue with this car that the oil burns at an extreme rate. this is a safety risk as it could lead to engine overheating, the engine could stall out due to the fast burning of the oil, or a potenti…”
2026-06-23 · Engine And Engine Cooling:engine:engine Control Module (Ecu/Ecm) · 1,500 mi“the contact owns a 2018 kia optima. the contact stated that while driving at an undisclosed speed, there was an abnormal odor and a knocking sound coming from the engine. the vehicle was taken to the dealer; however, the dealer was unable to duplicate the issue. the vehicle was not repaired. the issue persisted. the contact stated that the vehicle …”
2026-06-10 · Unknown Or Other“2018 kia optima dealer ed voyles kia smyrna began recall sc340. vehicle drove in running. dealer flashed ecm software, discovered non-original engine/ecu. vehicle now won’t start. dealer document states 'will not start after recall.' dealer refuses to restore to running condition citing prior repairs. this violates 49 usc 30120…”
Excerpts of consumer complaints filed with NHTSA, lightly truncated. They are owner statements, not verified findings.