2018 Kia Optima problems & reliability
230 owner complaints filed with NHTSA for the 2018 Kia Optima, alongside 2 safety recall campaigns. Last verified Aug 7, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several vehicles.
7 complaints report injuries (9 injured).
Federal crash records (FARS 2020–2023): 2018 Kia Optima vehicles were involved in 99 fatal crashes with 52 occupant deaths. Involvement counts are not adjusted for how many are on the road and do not imply fault or a vehicle defect.
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Engine | 129 | 56% |
| Unknown OR Other | 37 | 16% |
| Electrical System | 33 | 14% |
| Power Train | 18 | 8% |
| Service Brakes | 17 | 7% |
| Engine and Engine Cooling | 14 | 6% |
| Exterior Lighting | 14 | 6% |
| Fuel/propulsion System | 13 | 6% |
| Steering | 12 | 5% |
| Vehicle Speed Control | 10 | 4% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Half of the failures with a reported odometer reading occurred by 44,163 miles (middle 50% between 19,400 and 77,150 miles), based on 70 complaints that included mileage.
Complaints by incident year
What owners report
“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…”
Air Bags · filed Jul 19, 2026
“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…”
Engine · filed Jul 9, 2026
“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…”
Service Brakes · filed Jul 2, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Federal defect investigations
- Loss of Motive Power
Defect Petition DP22003 · opened Sep 12, 2022 · closed Dec 12, 2023
- Electrical overstress
Engineering Analysis EA19001 · opened Apr 19, 2019 · closed Sep 19, 2024 · led to recall 20V024
Technical service bulletins
155 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2018 Kia Optima. The 10 most recent:
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…
CS2312_TSB_R2 · Service Bulletin/Repair Instructions · issued Jun 8, 2026
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…
SC340_TSB_R5 · Emissions · issued Apr 4, 2026
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…
SC340_OWNR_JF&JFA_104 · Emissions · issued Mar 17, 2026
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…
SC340_TSB_R4 · Emissions · issued Mar 6, 2026
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…
TSB_CS2312_R1 · Service Bulletin/Repair Instructions · issued Feb 19, 2026
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…
SC340_OWNR_JF103 · Emissions · issued Dec 19, 2025
TECHNICAL SERVICE BULLETIN: CUSTOMER SATISFACTION: THEFT DETERRENT IGNITION CYLINDER PROTECTOR AND DECAL INSTALLATION (CS2312) - This bulletin provides information to install a Theft Deterrent Ignition Cylinder…
TSB_CS2312 · Service Bulletin/Repair Instructions · issued Dec 18, 2025
CUSTOMER SATISFACTION CAMPAIGN: OWNER NOTIFICATION (CS2312) - This document is the owner notification advising that Kia is conducting Customer Satisfaction Campaign. A software upgrade that addresses the social media…
CS2312_OWNR · Other · issued Dec 17, 2025
TECHNICAL SERVICE BULLETIN: VOLUNTARY EMISSIONS SERVICE CAMPAIGN: THETA II 2.4L GDI EMISSIONS ECM LOGIC IMPROVEMENT (SC340) - This bulletin has been revised to include additional information. New/revised sections of…
SC340_TSB_R3 · Service Bulletin/Repair Instructions · issued Dec 10, 2025
PITSTOP: TECHNICAL OPERATIONS: EXTERNAL DAMAGE TO ULTRASONIC SENSOR: This Pitstop provides information related to Parking Distance Warning (PDW) alerts and repairs involving ultrasonic sensors. The PDW system alerts the…
PS797 · Other · issued Dec 9, 2025
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2018 Kia Optima has 2 NHTSA recall campaigns — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2018 Kia Optima?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Owners most often reported problems around 44,163 miles — budget accordingly if the car is approaching that mileage.