AutoUtility currently tracks 378 official NHTSA owner defect complaints for the 2018 Hyundai Sonata. Engine & Cooling issues are the most frequently reported category, appearing in 199 complaints (52.6% of submitted records). Among these NHTSA complaint records, 18 filings cite a crash, 13 cite a fire, 10 report one or more injuries, 1 reports one or more fatalities.

Key Problem Findings
  • Total NHTSA Complaints: 378 reports
  • #1 Reported Problem Area: Engine & Cooling (199 reports • 52.6% of submitted complaints)
  • Secondary Problem Areas: Electrical System (62), Powertrain & Transmission (41)
  • Crash-Citing Complaints: 18 filings
  • Fire-Citing Complaints: 13 filings
  • Complaints Reporting Injuries / Fatalities: 10 injury filings • 1 fatality filings
Reporting Methodology: Statistics describe unverified consumer submissions voluntarily filed with NHTSA. Complaint volume is not normalized for vehicle sales volume or miles driven. Multiple components can be cited within a single owner complaint submission.
Total Complaints
378
Submitted to NHTSA ODI
Crash-Citing Complaints
18
Filings citing a collision
Fire-Citing Complaints
13
Filings citing smoke or fire
Complaints Reporting Injuries
10
Filings citing one or more injuries
Complaints Reporting Fatalities
1
Consumer filings citing fatalities

Most Reported Problems for 2018 Hyundai Sonata

Top automotive subsystem defect categories ranked by unique owner complaint volume in federal records

#1 Problem Area 52.6% of complaints

Engine & Cooling

199 owner complaints submitted to NHTSA ODI
⚠️ 3 crash reports 🔥 7 fire reports 🩹 2 injury report entries
#2 Problem Area 16.4% of complaints

Electrical System

62 owner complaints submitted to NHTSA ODI
⚠️ 3 crash reports 🔥 4 fire reports 🩹 2 injury report entries
#3 Problem Area 10.8% of complaints

Powertrain & Transmission

41 owner complaints submitted to NHTSA ODI
⚠️ 2 crash reports 🔥 1 fire report 🩹 1 injury report entry
#4 Problem Area 8.7% of complaints

Fuel & Propulsion System

33 owner complaints submitted to NHTSA ODI
🔥 1 fire report
#5 Problem Area 7.9% of complaints

Driver Assistance & Safety Tech

30 owner complaints submitted to NHTSA ODI
⚠️ 7 crash reports 🩹 4 injury report entries
Domain Share Note: Share percentage represents the proportion of unique complaint filings referencing each vehicle system. Because single complaints may cite multiple systems (such as engine and electrical simultaneously), domain percentages represent individual category incidence and may sum to over 100%.

Symptoms Mentioned in NHTSA Owner Reports for 2018 Hyundai Sonata

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 & Cooling 6.9% of complaints

Engine Coolant Intrusion / Oil Leak

26 complaint narratives describe this symptom
Powertrain & Transmission 6.1% of complaints

Loss of Motive Power While Driving

23 complaint narratives describe this symptom
Symptom Identification Method: A complaint may describe more than one symptom, so percentages may sum to more than 100%. Symptom identification reflects text contained in consumer-submitted complaint records and does not establish a confirmed mechanical diagnosis.

Recent NHTSA Owner Reports for 2018 Hyundai Sonata

Representative defect filings submitted by owners to the NHTSA Office of Defects Investigation

Engine & Cooling NHTSA ODI ID: #11759477
Filed: 08/25/2026

"Since I had Service Campaign 9C2 completed, the car hesitates to start, does a mini-lurch upon cold start and runs rough. Two weeks ago, it was put in park, lurched backwards, then died. The starter and battery have been replaced but this has not helped. The car ran fine before this update was done."

Incident Date: 07/17/2026 • Raw NHTSA Component: ENGINE
Engine & Cooling NHTSA ODI ID: #11757263
Filed: 08/16/2026

"The paint on all parts of the car is completely coming off down to bare metal. It’s as if the car wasn’t prepped to receive paint. Every Hyundai I pass that’s white the paint is coming off. There is also an internal engine oil leak where I’m losing 4qts of oil a week."

Incident Date: 07/15/2022 • Raw NHTSA Component: STRUCTURE,ENGINE
Powertrain & Transmission NHTSA ODI ID: #11757253
Filed: 08/16/2026

"I recently had the 9C2 Emissions recall update performed on my car, and since the update my car drives like total garbage after a cold start. It hesitates to accelerate, it bucks when trying to accelerate, and it’s to the point the engine is about to stall. I took it back to the Hyundai dealership..."

Incident Date: 07/14/2026 • Raw NHTSA Component: POWER TRAIN,ENGINE
Fuel & Propulsion System NHTSA ODI ID: #11752670
Filed: 07/24/2026

"The contact owns a 2018 Hyundai Sonata. The contact stated that while operating the vehicle, there was an abnormal fuel odor inside the vehicle. The vehicle was taken to the local dealer and was diagnosed with an inoperable low-pressure fuel pump. The contact was informed that the low-pressure fuel..."

Incident Date: 05/11/2026 • Raw NHTSA Component: FUEL SYSTEM, GASOLINE
Engine & Cooling NHTSA ODI ID: #11751641
Filed: 07/20/2026

"The lower aluminum engine oil pan developed a structural hairline fracture ("micro-crack") directly along the factory casting ridge adjacent to the drain plug. The component failed without any external impact, road hazard, scraping, or underbody damage. The failure was officially confirmed and..."

Incident Date: 07/13/2026 • Raw NHTSA Component: ENGINE
Consumer Narrative Notice: Excerpts are sanitized text descriptions submitted by vehicle owners to the federal ODI database. They reflect the reporting consumer's observations at the time of filing and have not been independently confirmed by vehicle manufacturers or government investigators.

Complaint History for Hyundai Sonata

Reported defect complaint volume across sibling model years (2015–2026)

Model Year NHTSA Complaints Crash Reports Safety Recalls Detailed Report
2015 Hyundai Sonata 1192 38 12 View 2015 Problems →
2016 Hyundai Sonata 850 23 8 View 2016 Problems →
2017 Hyundai Sonata 840 29 4 View 2017 Problems →
2018 Hyundai Sonata Current Page 378 18 1 Current
2019 Hyundai Sonata 163 9 0 View 2019 Problems →
2020 Hyundai Sonata 189 5 4 View 2020 Problems →
2021 Hyundai Sonata 182 8 4 View 2021 Problems →
2022 Hyundai Sonata 110 8 3 View 2022 Problems →
2023 Hyundai Sonata 100 8 2 View 2023 Problems →
2024 Hyundai Sonata 54 1 1 View 2024 Problems →
2025 Hyundai Sonata 27 1 0 View 2025 Problems →
2026 Hyundai Sonata 0 0 1 View 2026 Problems →
Comparative Disclaimer: Complaint totals are unadjusted historical counts and are not normalized for vehicles sold, active fleet size, or total road mileage. Newer model years naturally have had less calendar exposure time to accumulate owner filings.

Detailed NHTSA Component Breakdown for 2018 Hyundai Sonata

Complete distribution of consumer defect reports across all 77 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 118 1 5 0 0
Other / Uncategorized NHTSA category: UNKNOWN OR OTHER 33 1 2 0 0
EXTERIOR LIGHTING 17 0 0 0 0
ELECTRICAL SYSTEM,ENGINE 16 0 0 0 0
Engine & Cooling NHTSA category: ENGINE AND ENGINE COOLING 11 0 0 0 0
Structure & Body NHTSA category: STRUCTURE 11 0 0 0 0
POWER TRAIN,ENGINE 10 0 0 0 0
POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM 9 0 0 0 0
ENGINE,FUEL/PROPULSION SYSTEM 8 0 0 0 0
UNKNOWN OR OTHER,ENGINE 8 0 0 0 0
Electrical System NHTSA category: ELECTRICAL SYSTEM 7 0 1 0 0
ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM 7 0 1 0 0
Powertrain NHTSA category: POWER TRAIN 7 0 0 0 0
Doors, Latches & Locks NHTSA category: LATCHES/LOCKS/LINKAGES 6 0 0 0 0
Vehicle Speed Control NHTSA category: VEHICLE SPEED CONTROL 6 4 0 0 0
ELECTRICAL SYSTEM,UNKNOWN OR OTHER 5 0 0 0 0
POWER TRAIN,ELECTRICAL SYSTEM,ENGINE 5 1 1 1 0
Air Bags NHTSA category: AIR BAGS 4 2 0 1 1
Fuel & Propulsion System NHTSA category: FUEL/PROPULSION SYSTEM 4 0 0 0 0
Seat Belts NHTSA category: SEAT BELTS 4 1 0 1 0
Service Brakes NHTSA category: SERVICE BRAKES 4 2 1 11 0
ELECTRICAL SYSTEM,UNKNOWN OR OTHER,ENGINE 3 0 0 0 0
ELECTRICAL SYSTEM,VEHICLE SPEED CONTROL,ENGINE 3 0 0 0 0
Forward Collision Avoidance NHTSA category: FORWARD COLLISION AVOIDANCE 3 0 0 0 0
POWER TRAIN,VEHICLE SPEED CONTROL,ENGINE 3 0 0 0 0
Steering NHTSA category: STEERING 3 0 0 0 0
Tires NHTSA category: TIRES 3 0 0 0 0
ELECTRICAL SYSTEM,EXTERIOR LIGHTING 2 0 0 0 0
ELECTRICAL SYSTEM,EXTERIOR LIGHTING,ENGINE 2 0 0 0 0
ELECTRICAL SYSTEM,UNKNOWN OR OTHER,SERVICE BRAKES 2 0 0 0 0
SEAT BELTS,ENGINE 2 1 0 1 0
Service Brakes NHTSA category: SERVICE BRAKES, HYDRAULIC 2 1 0 1 0
STEERING,ENGINE 2 0 0 0 0
STRUCTURE,ENGINE 2 0 0 0 0
STRUCTURE,UNKNOWN OR OTHER 2 0 0 0 0
VEHICLE SPEED CONTROL,SERVICE BRAKES 2 1 0 1 0
Visibility & Wipers NHTSA category: VISIBILITY/WIPER 2 0 0 0 0
ELECTRICAL SYSTEM,ELECTRONIC STABILITY CONTROL (ESC),ENGINE 1 0 1 0 0
ELECTRICAL SYSTEM,ENGINE,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
ELECTRICAL SYSTEM,LATCHES/LOCKS/LINKAGES 1 0 0 0 0
ELECTRICAL SYSTEM,SERVICE BRAKES,FORWARD COLLISION AVOIDANCE 1 1 0 1 0
ELECTRICAL SYSTEM,STRUCTURE 1 0 0 0 0
ELECTRICAL SYSTEM,TIRES,SERVICE BRAKES 1 0 0 0 0
ENGINE AND ENGINE COOLING,ENGINE 1 0 0 0 0
ENGINE AND ENGINE COOLING,FUEL SYSTEM, GASOLINE,POWER TRAIN 1 0 0 0 0
ENGINE AND ENGINE COOLING,LATCHES/LOCKS/LINKAGES,ENGINE 1 0 0 0 0
EXTERIOR LIGHTING,ELECTRONIC STABILITY CONTROL (ESC),VISIBILITY/WIPER 1 0 0 0 0
EXTERIOR LIGHTING,ENGINE,VISIBILITY/WIPER 1 0 0 0 0
EXTERIOR LIGHTING,UNKNOWN OR OTHER,ENGINE 1 0 0 0 0
FIRERELATED 1 0 1 1 0
Fuel System NHTSA category: FUEL SYSTEM, GASOLINE 1 0 0 0 0
LANE DEPARTURE,BACK OVER PREVENTION 1 0 0 0 0
LANE DEPARTURE,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
POWER TRAIN,ELECTRICAL SYSTEM 1 1 0 0 0
POWER TRAIN,ELECTRICAL SYSTEM,AIR BAGS 1 0 0 0 0
POWER TRAIN,FUEL/PROPULSION SYSTEM 1 0 0 0 0
POWER TRAIN,UNKNOWN OR OTHER,ENGINE 1 0 0 0 0
SEAT BELTS,ENGINE,VISIBILITY/WIPER 1 0 0 0 0
SEAT BELTS,VISIBILITY 1 0 0 0 0
Seats & Restraints NHTSA category: SEATS 1 0 0 0 0
SERVICE BRAKES, HYDRAULIC,VEHICLE SPEED CONTROL 1 1 0 2 0
SERVICE BRAKES,ENGINE 1 0 0 0 0
SERVICE BRAKES,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
STEERING,ELECTRICAL SYSTEM,ENGINE 1 0 0 0 0
STEERING,ELECTRICAL SYSTEM,VEHICLE SPEED CONTROL 1 0 0 0 0
STEERING,POWER TRAIN,ENGINE 1 0 0 0 0
STEERING,SUSPENSION,POWER TRAIN 1 0 0 0 0
Suspension NHTSA category: SUSPENSION 1 0 0 0 0
SUSPENSION,ENGINE 1 0 0 0 0
SUSPENSION,SEATS,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
UNKNOWN OR OTHER,ENGINE,FUEL/PROPULSION SYSTEM 1 0 0 0 0
UNKNOWN OR OTHER,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
UNKNOWN OR OTHER,LANE DEPARTURE 1 0 0 0 0
UNKNOWN OR OTHER,SERVICE BRAKES 1 0 0 0 0
VEHICLE SPEED CONTROL,ENGINE 1 0 0 0 0
VEHICLE SPEED CONTROL,ENGINE,FUEL/PROPULSION SYSTEM 1 0 0 0 0
VEHICLE SPEED CONTROL,SERVICE BRAKES,ENGINE 1 0 0 0 0
Data Attribution & Reporting Methodology: Complaints are unverified voluntary submissions to the NHTSA Office of Defects Investigation (ODI). Because multiple vehicle components can be cited within a single owner complaint submission, component-level rollups may sum to more than the unique complaint count (378). Injury and fatality entries in the detailed table reflect raw values entered by reporting consumers across individual submissions; they are not deduplicated casualty statistics and may include duplicate or unverified entries. Complaint volume is not normalized for sales volume or vehicle mileage and does not represent an audited component failure rate.

Official NHTSA Defect Investigations (3)

3 CLOSED

Formal safety defect inquiries and engineering analyses opened by the NHTSA Office of Defects Investigation (ODI)

Official Federal Inquiries: NHTSA opens a defect investigation when safety screening or consumer defect trends indicate a potential unreasonable safety risk. An open investigation is a formal inquiry and does not by itself confirm a defect or result in a mandatory recall.
CLOSED Defect Petition (DP) ODI Action #DP22005
Opened: 2023-01-27 • Closed: 2023-08-07

Pedestrian alert sounds

Affected Component: ELECTRICAL SYSTEM:PROPULSION SYSTEM

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...

✓ Resulted in Safety Recall Campaign: 22V063000 Official NHTSA File →
CLOSED Defect Petition (DP) ODI Action #DP22003
Opened: 2022-09-12 • Closed: 2023-12-12

Loss of Motive Power

Affected Component: ENGINE

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...

Closed without associated recall campaign. Official NHTSA File →
CLOSED Engineering Analysis (EA) ODI Action #EA19001
Opened: 2019-04-19 • Closed: 2024-09-19

Electrical overstress

Affected Component: AIR BAGS: AIR BAG/RESTRAINT CONTROL MODULE

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...

✓ Resulted in Safety Recall Campaign: 20V024 Official NHTSA File →
Official US Government Data Provenance

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.