AutoUtility currently tracks 242 official NHTSA owner defect complaints for the 2018 Kia Optima. Engine & Cooling issues are the most frequently reported category, appearing in 141 complaints (58.3% of submitted records). Among these NHTSA complaint records, 10 filings cite a crash, 10 cite a fire, 7 report one or more injuries.
- • Total NHTSA Complaints: 242 reports
- • #1 Reported Problem Area: Engine & Cooling (141 reports • 58.3% of submitted complaints)
- • Secondary Problem Areas: Electrical System (37), Powertrain & Transmission (20)
- • Crash-Citing Complaints: 10 filings
- • Fire-Citing Complaints: 10 filings
- • Complaints Reporting Injuries / Fatalities: 7 injury filings • 0 fatality filings
Most Reported Problems for 2018 Kia Optima
Top automotive subsystem defect categories ranked by unique owner complaint volume in federal records
Engine & Cooling
NHTSA records list 1 official safety recall campaign for this model year involving the same broad component area:
- Campaign #21V844000 ENGINE
Electrical System
Powertrain & Transmission
Brakes & Traction Control
Fuel & Propulsion System
NHTSA records list 1 official safety recall campaign for this model year involving the same broad component area:
- Campaign #18V161000 HYBRID PROPULSION SYSTEM
Symptoms Mentioned in NHTSA Owner Reports for 2018 Kia Optima
Specific mechanical, electrical, and driver-assist defect symptoms identified via deterministic narrative analysis
AutoUtility uses deterministic phrase matching to identify recurring symptom descriptions within consumer-submitted NHTSA complaint narratives.
Engine Coolant Intrusion / Oil Leak
Loss of Motive Power While Driving
Recent NHTSA Owner Reports for 2018 Kia Optima
Representative defect filings submitted by owners to the NHTSA Office of Defects Investigation
"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..."
"See attached document for complaint."
"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..."
"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..."
"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..."
Complaint History for Kia Optima
Reported defect complaint volume across sibling model years (2015–2020)
| Model Year | NHTSA Complaints | Crash Reports | Safety Recalls | Detailed Report |
|---|---|---|---|---|
| 2015 Kia Optima | 1019 | 31 | 4 | View 2015 Problems → |
| 2016 Kia Optima | 758 | 27 | 5 | View 2016 Problems → |
| 2017 Kia Optima | 303 | 6 | 4 | View 2017 Problems → |
| 2018 Kia Optima Current Page | 242 | 10 | 3 | Current |
| 2019 Kia Optima | 205 | 20 | 1 | View 2019 Problems → |
| 2020 Kia Optima | 143 | 6 | 0 | View 2020 Problems → |
Detailed NHTSA Component Breakdown for 2018 Kia Optima
Complete distribution of consumer defect reports across all 64 granular NHTSA system and subsystem classifications
| Vehicle Component / System | Total Complaints | Crash Reports | Fire Reports | Reported Injury Entries | Reported Fatality Entries |
|---|---|---|---|---|---|
| Engine NHTSA category: ENGINE | 88 | 1 | 5 | 0 | 0 |
| Other / Uncategorized NHTSA category: UNKNOWN OR OTHER | 16 | 0 | 0 | 0 | 0 |
| Engine & Cooling NHTSA category: ENGINE AND ENGINE COOLING | 12 | 0 | 0 | 0 | 0 |
| Electrical System NHTSA category: ELECTRICAL SYSTEM | 8 | 0 | 0 | 0 | 0 |
| EXTERIOR LIGHTING | 8 | 0 | 0 | 0 | 0 |
| Powertrain NHTSA category: POWER TRAIN | 8 | 1 | 0 | 2 | 0 |
| Service Brakes NHTSA category: SERVICE BRAKES | 7 | 1 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,UNKNOWN OR OTHER,ENGINE | 5 | 0 | 1 | 0 | 0 |
| Steering NHTSA category: STEERING | 5 | 0 | 0 | 0 | 0 |
| UNKNOWN OR OTHER,ENGINE | 5 | 0 | 0 | 0 | 0 |
| Air Bags NHTSA category: AIR BAGS | 4 | 4 | 0 | 4 | 0 |
| ELECTRICAL SYSTEM,EXTERIOR LIGHTING | 4 | 0 | 1 | 0 | 0 |
| Structure & Body NHTSA category: STRUCTURE | 4 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,ENGINE | 3 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,UNKNOWN OR OTHER | 3 | 0 | 0 | 0 | 0 |
| AIR BAGS,SEAT BELTS | 2 | 2 | 0 | 2 | 0 |
| ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM | 2 | 0 | 0 | 0 | 0 |
| ENGINE,FUEL/PROPULSION SYSTEM | 2 | 0 | 0 | 0 | 0 |
| Fuel & Propulsion System NHTSA category: FUEL/PROPULSION SYSTEM | 2 | 0 | 0 | 0 | 0 |
| POWER TRAIN,ELECTRICAL SYSTEM,ENGINE | 2 | 0 | 0 | 0 | 0 |
| POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM | 2 | 0 | 0 | 0 | 0 |
| POWER TRAIN,UNKNOWN OR OTHER,ENGINE | 2 | 0 | 1 | 0 | 0 |
| POWER TRAIN,VEHICLE SPEED CONTROL,ENGINE | 2 | 0 | 0 | 0 | 0 |
| Seat Belts NHTSA category: SEAT BELTS | 2 | 0 | 0 | 0 | 0 |
| STEERING,ENGINE | 2 | 0 | 0 | 0 | 0 |
| UNKNOWN OR OTHER,SERVICE BRAKES | 2 | 0 | 0 | 0 | 0 |
| VEHICLE SPEED CONTROL,ENGINE | 2 | 0 | 0 | 0 | 0 |
| Visibility & Wipers NHTSA category: VISIBILITY/WIPER | 2 | 0 | 0 | 0 | 0 |
| AIR BAGS,ENGINE | 1 | 0 | 1 | 0 | 0 |
| AIR BAGS,STRUCTURE,SERVICE BRAKES | 1 | 1 | 0 | 1 | 0 |
| AIR BAGS,UNKNOWN OR OTHER,ENGINE | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,ELECTRONIC STABILITY CONTROL (ESC),ENGINE | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,EXTERIOR LIGHTING,UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,SEAT BELTS | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,SERVICE BRAKES,ENGINE | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM | 1 | 0 | 0 | 0 | 0 |
| ELECTRONIC STABILITY CONTROL (ESC),SERVICE BRAKES | 1 | 0 | 0 | 0 | 0 |
| ENGINE AND ENGINE COOLING,ENGINE | 1 | 0 | 0 | 0 | 0 |
| ENGINE AND ENGINE COOLING,LATCHES/LOCKS/LINKAGES | 1 | 0 | 0 | 0 | 0 |
| ENGINE,ELECTRICAL SYSTEM | 1 | 0 | 0 | 0 | 0 |
| ENGINE,ENGINE AND ENGINE COOLING | 1 | 0 | 0 | 0 | 0 |
| ENGINE,FIRERELATED | 1 | 0 | 1 | 0 | 0 |
| EXTERIOR LIGHTING,FUEL/PROPULSION SYSTEM | 1 | 0 | 0 | 0 | 0 |
| Forward Collision Avoidance NHTSA category: FORWARD COLLISION AVOIDANCE | 1 | 0 | 0 | 0 | 0 |
| FUEL/PROPULSION SYSTEM,LANE DEPARTURE | 1 | 0 | 0 | 0 | 0 |
| POWER TRAIN,ENGINE | 1 | 0 | 0 | 0 | 0 |
| POWER TRAIN,ENGINE,LANE DEPARTURE | 1 | 0 | 0 | 0 | 0 |
| POWER TRAIN,UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| POWER TRAIN,VEHICLE SPEED CONTROL,UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| SERVICE BRAKES,ENGINE | 1 | 0 | 0 | 0 | 0 |
| STEERING,ELECTRICAL SYSTEM,ELECTRONIC STABILITY CONTROL (ESC) | 1 | 0 | 0 | 0 | 0 |
| STEERING,ELECTRICAL SYSTEM,ENGINE | 1 | 0 | 0 | 0 | 0 |
| STEERING,ELECTRICAL SYSTEM,SERVICE BRAKES | 1 | 0 | 0 | 0 | 0 |
| STEERING,ELECTRICAL SYSTEM,SERVICE BRAKES,ENGINE | 1 | 0 | 0 | 0 | 0 |
| STEERING,ENGINE,FUEL/PROPULSION SYSTEM | 1 | 0 | 0 | 0 | 0 |
| STEERING,VEHICLE SPEED CONTROL,ENGINE | 1 | 0 | 0 | 0 | 0 |
| STRUCTURE,UNKNOWN OR OTHER,ENGINE | 1 | 0 | 0 | 0 | 0 |
| STRUCTURE,WHEELS,SERVICE BRAKES | 1 | 0 | 0 | 0 | 0 |
| SUSPENSION,ENGINE,LANE DEPARTURE | 1 | 0 | 0 | 0 | 0 |
| Tires NHTSA category: TIRES | 1 | 0 | 0 | 0 | 0 |
| Vehicle Speed Control NHTSA category: VEHICLE SPEED CONTROL | 1 | 0 | 0 | 0 | 0 |
| VEHICLE SPEED CONTROL,ENGINE,FUEL/PROPULSION SYSTEM | 1 | 0 | 0 | 0 | 0 |
| VEHICLE SPEED CONTROL,SERVICE BRAKES,FUEL/PROPULSION SYSTEM | 1 | 0 | 0 | 0 | 0 |
| VEHICLE SPEED CONTROL,UNKNOWN OR OTHER,ENGINE | 1 | 0 | 0 | 0 | 0 |
Official NHTSA Defect Investigations (4)
Formal safety defect inquiries and engineering analyses opened by the NHTSA Office of Defects Investigation (ODI)
Pedestrian alert sounds
NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles. The standard applies to hybrid and electric vehicles that have a gross vehicle weight ra...
Loss of Motive Power
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints indicating that the subject vehicles were experienc...
Engine Fires
On March 29, 2019, the Office of Defects Investigation (ODI) opened two Preliminary Evaluations (PE19-003 on Hyundai and PE19-004 on Kia) to broadly investigate incidents of non-crash fires (regardless of origin or operational status of the vehicle) on various model year Hyundai and Kia vehicles. During the PE investigations, Hyundai and Kia issued several recalls to address vehicle fires, including those due to engine failures involving variou...
Electrical overstress
The Office of Defects Investigation (ODI) opened this investigation to determine if the failure of airbags to deploy during severe crashes, in certain vehicles, was the result of a safety related defect. During the investigation a complex failure was studied that can result in non-deployment of subject vehicle air bags and other restraint system devices in severe crash events. The subject vehicles may be equipped with an airbag control unit (AC...
The complaint records on this page are retrieved directly from the NHTSA Office of Defects Investigation (ODI) public database.
Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.