YearToAvoid

2018 Mazda CX-9 Engine Problems

NHTSA lists 78 engine complaints for the 2018 Mazda CX-9, 61% of all complaints for the year, with a median mileage at failure of 72,000. The dominant pattern is cracked cylinder heads causing coolant loss and overheating. No related recall is listed for this issue.

Engine complaints
78
61% of 128
Crashes reported
0
Fires reported
0
Injuries reported
0
Median mileage
72,000 mi
Related recalls
0

Typical engine symptoms owners report

  • Owners report cracked cylinder heads that leak coolant and trigger overheating warnings, often discovered after noticing an antifreeze smell or dropping coolant level.
  • Several drivers describe the temperature gauge climbing to dangerous levels while driving, forcing them to pull over to avoid further engine damage.
  • Some owners say dealers confirmed the cracked cylinder head and needed to replace part or all of the engine.
  • One complaint describes sudden unintended acceleration at a stop, requiring the driver to shift into park and shut off the engine to stop the vehicle.
  • A separate report describes loud rattling and gear slippage tied to a failing water pump bearing found by the dealer.

When 2018 Mazda CX-9 engine complaints were filed

First complaint Jul 17, 2019, latest Sep 17, 2026.

2018 Mazda CX-9 engine complaints: complaints filed per month5Jul 2019Sep 2022Mar 2023Aug 2023Jan 2024Jul 2024Apr 2025Jun 2026
78 complaints filed with NHTSA from Jul 2019 to Sep 2026; peak Aug 2023 (5).

Engine recalls for the 2018 Mazda CX-9

No safety recalls on record for this model year.

Engine complaints by CX-9 model year

Raw complaint counts per model year; newer years have had less time to accumulate complaints.

  1. 201035 (18%)
  2. 201118 (11%)
  3. 201232 (14%)
  4. 201317 (25%)
  5. 201420 (37%)
  6. 201518 (51%)
  7. 201670 (67%)
  8. 201743 (70%)
  9. 201878 (61%)
  10. 201923 (43%)
  11. 20205 (26%)
  12. 202121 (54%)
  13. 20220 (0%)
  14. 20230 (0%)

Frequently asked questions

How common are engine problems on the 2018 Mazda CX-9?
NHTSA lists 78 engine complaints for the 2018 CX-9, which is 61% of all 128 complaints filed for that model year.
What is the most reported engine issue on the 2018 CX-9?
The most frequently described pattern is a cracked cylinder head that leaks coolant and causes overheating, sometimes leading to engine replacement.
At what mileage do 2018 CX-9 engine problems typically show up?
NHTSA data shows a median mileage at failure of 72,000 miles for engine-related complaints on this model year.
Is there a recall for the 2018 Mazda CX-9 engine?
No related recall is listed in NHTSA data for the engine complaints on the 2018 CX-9.
Have the engine problems caused crashes or fires?
NHTSA records zero crashes and zero fires among the reported engine complaints for the 2018 CX-9.

Sources: NHTSA Office of Defects Investigation complaint and recall databases; U.S. EPA fuel economy data; NHTSA 5-Star Safety Ratings. Complaints are unverified owner reports.

Data updated Sep 24, 2026. Read the methodology and data sources. The Complaint Index is based on NHTSA owner complaints and recalls; it is not a reliability rating.