AutoUtility currently tracks 56 official NHTSA owner defect complaints for the 2018 Mazda Mazda6. Engine & Cooling issues are the most frequently reported category, appearing in 30 complaints (53.6% of submitted records). Among these NHTSA complaint records, 1 filing cites a crash, 1 cites a fire, 1 reports one or more injuries.

Key Problem Findings
  • Total NHTSA Complaints: 56 reports
  • #1 Reported Problem Area: Engine & Cooling (30 reports • 53.6% of submitted complaints)
  • Secondary Problem Areas: Powertrain & Transmission (9), Fuel & Propulsion System (6)
  • Crash-Citing Complaints: 1 filings
  • Fire-Citing Complaints: 1 filings
  • Complaints Reporting Injuries / Fatalities: 1 injury filings • 0 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
56
Submitted to NHTSA ODI
Crash-Citing Complaints
1
Filings citing a collision
Fire-Citing Complaints
1
Filings citing smoke or fire
Complaints Reporting Injuries
1
Filings citing one or more injuries
Complaints Reporting Fatalities
0
Consumer filings citing fatalities

Most Reported Problems for 2018 Mazda Mazda6

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

#1 Problem Area 53.6% of complaints

Engine & Cooling

30 owner complaints submitted to NHTSA ODI
⚠️ NHTSA Recall Context

NHTSA records list 1 official safety recall campaign for this model year involving the same broad component area:

*Component overlap means an official recall exists for the same broad vehicle system. It does not establish that an individual owner complaint was caused by, covered by, or resolved through that recall.
🔥 1 fire report
#2 Problem Area 16.1% of complaints

Powertrain & Transmission

9 owner complaints submitted to NHTSA ODI
✓ 0 crashes or fires cited
#3 Problem Area 10.7% of complaints

Fuel & Propulsion System

6 owner complaints submitted to NHTSA ODI
⚠️ NHTSA Recall Context

NHTSA records list 1 official safety recall campaign for this model year involving the same broad component area:

*Component overlap means an official recall exists for the same broad vehicle system. It does not establish that an individual owner complaint was caused by, covered by, or resolved through that recall.
✓ 0 crashes or fires cited
#4 Problem Area 7.1% of complaints

Brakes & Traction Control

4 owner complaints submitted to NHTSA ODI
✓ 0 crashes or fires cited
#5 Problem Area 7.1% of complaints

Electrical System

4 owner complaints submitted to NHTSA ODI
🔥 1 fire report
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 Mazda Mazda6

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 21.4% of complaints

Engine Coolant Intrusion / Oil Leak

12 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 Mazda Mazda6

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

Engine & Cooling NHTSA ODI ID: #11755535
Filed: 08/07/2026

"The car only has 70k miles on it. The engine started smoking under the hood. Immediately stopped to look. There was oil leaking but I could not see from where. I took it across the street to the Toyota dealership and had them look at it. They explained to me that there was a crack in the cylinder..."

Incident Date: 08/07/2026 • Raw NHTSA Component: ENGINE
Driver Assistance & Safety Tech NHTSA ODI ID: #11753644
Filed: 07/29/2026

"Got error message that said "Forward Smart City Brake Support Malfunction" slso fot "smart brake malfunction" while driving. The ac stopped, the car speedometer kept going from 50 to zero. The car died and couldn't open doors, windows. Lost steering while driving. We were able to get off road and..."

Incident Date: 07/29/2026 • Raw NHTSA Component: STEERING,SUSPENSION,VEHICLE SPEED CONTROL
Engine & Cooling NHTSA ODI ID: #11734993
Filed: 04/30/2026

"Crack in Cylinder Head of engine. Mazda has been sued about this and have issued recalls on turbo engines, but not on non turbo ones though its the same systemic design issue with these engines. Wants me to pay 5-7k out of pocket."

Incident Date: 04/25/2026 • Raw NHTSA Component: ENGINE
Engine & Cooling NHTSA ODI ID: #11733118
Filed: 04/22/2026

"My cylinder head is leaking coolant. There is a well known and well documented issue with these cylinder heads cracking due to poor casting. This has become such a big issue that Mazda has even recalled the cylinder heads, BUT, only if the engine is equipped with Turbo. However, this issue is..."

Incident Date: 06/01/2025 • Raw NHTSA Component: ENGINE
Engine & Cooling NHTSA ODI ID: #11729758
Filed: 04/07/2026

"Car had a coolant leak due to cracked cylinder head that was defective from the factory it was fixed but now the car has engine problems again. Don’t want to keep having these issues in the future"

Incident Date: 04/04/2026 • 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 Mazda Mazda6

Reported defect complaint volume across sibling model years (2015–2021)

Model Year NHTSA Complaints Crash Reports Safety Recalls Detailed Report
2015 Mazda Mazda6 60 6 3 View 2015 Problems →
2016 Mazda Mazda6 76 9 1 View 2016 Problems →
2017 Mazda Mazda6 60 1 1 View 2017 Problems →
2018 Mazda Mazda6 Current Page 56 1 2 Current
2019 Mazda Mazda6 6 0 1 View 2019 Problems →
2020 Mazda Mazda6 2 0 0 View 2020 Problems →
2021 Mazda Mazda6 17 0 0 View 2021 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 Mazda Mazda6

Complete distribution of consumer defect reports across all 22 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 22 0 0 0 0
Other / Uncategorized NHTSA category: UNKNOWN OR OTHER 4 0 0 0 0
Fuel System NHTSA category: FUEL SYSTEM, GASOLINE 3 0 0 0 0
POWER TRAIN,ENGINE 3 0 0 0 0
Service Brakes NHTSA category: SERVICE BRAKES 3 0 0 0 0
Powertrain NHTSA category: POWER TRAIN 2 0 0 0 0
Structure & Body NHTSA category: STRUCTURE 2 0 0 0 0
UNKNOWN OR OTHER,ENGINE 2 0 0 0 0
Visibility & Wipers NHTSA category: VISIBILITY/WIPER 2 0 0 0 0
Back Over Prevention / Camera NHTSA category: BACK OVER PREVENTION 1 0 0 0 0
ELECTRICAL SYSTEM,ENGINE 1 0 0 0 0
ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM 1 0 0 0 0
ELECTRICAL SYSTEM,UNKNOWN OR OTHER,ENGINE 1 0 1 0 0
Equipment & Accessories NHTSA category: EQUIPMENT 1 0 0 0 0
Fuel & Propulsion System NHTSA category: FUEL/PROPULSION SYSTEM 1 0 0 0 0
POWER TRAIN,ELECTRICAL SYSTEM 1 0 0 0 0
POWER TRAIN,UNKNOWN OR OTHER,ENGINE 1 0 0 0 0
Seat Belts NHTSA category: SEAT BELTS 1 1 0 1 0
STEERING,SUSPENSION,VEHICLE SPEED CONTROL 1 0 0 0 0
SUSPENSION,POWER TRAIN,SERVICE BRAKES 1 0 0 0 0
SUSPENSION,POWER TRAIN,WHEELS 1 0 0 0 0
UNKNOWN OR OTHER,ENGINE,FUEL/PROPULSION SYSTEM 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 (56). 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 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.