There are 2 owner-reported electrical system complaints for the 2017 Mazda CX-9in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
My vehicle has several issues related to a water pump failure in which the check engine light did not remain on. The vehicle began to over heat and slow down on the highway/ roads despite having my foot on the gas. My vehicle is now at Heritage Mazda Catonsville and unable to be read by the OBD reader which may be related to a weak wiring harness reported by other owners of the CX9. It also my be why my check engine light is not on despite having an engine issue. Many others have reported a failed water pump which caused cracks in the head which causes the car to over heat and slow down without notice. Despite having thousands of customers with this issue Mazda has yet to issue a recall.
The first sign of an issue was an oil pressure indicator on the dashboard, but upon inspection, the oil levels seemed completely normal. The dashboard light went away shortly after that. A day later, I was on my lunch break and parked my car in a garage for 45 minutes. On the drive there, I did not notice any issues and was able to operate the vehicle fine for the short distance that I drove. When I returned to my parked car, there was a large puddle of oil underneath. I immediately had a mechanic take a look at the car. The mechanic was able to identify a cracked cylinder head, which led to water and coolant entering the engine. He highly suspects that this caused a blown head gasket in the car as well. As well as that, the car's starter, which worked just fine on day 1 of the issue and has never had any problems before, has totally ceased function. If I had not noticed the oil pool underneath the car and driven back to work as usual, it could have caused the engine to seize and create a very dangerous situation for myself and others on the road, including but not limited to the potential of an engine fire with the level of oil lost. The car was up to date on its servicing, including oil changes. Two ASE certified mechanics have inspected the vehicle and confirmed the leaked fluids and aforementioned issues. No other professionals inspected the vehicle (insurance representatives, law enforcement, etc.).
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026