2019 Mazda CX-9 engine problems

Related recalls

No recalls on file.

What owners say

1. Filed Jul 10, 2026KYEngineTransmission & Drivetrain

   The engine cylinder head developed an internal coolant leak, allowing coolant to enter the combustion chamber. This caused engine overheating and smoke coming from the tailpipe while driving. A dealer performed a coolant pressure test confirming coolant leaking into the combustion chamber, and wet/dry compression testing on all 4 cylinders showed low and inconsistent readings consistent with cylinder head coolant intrusion (Cylinder 1: 105/125 psi, Cylinder 2: 115/125 psi,…

   NHTSA complaint #11749615 · source
2. Filed Jun 18, 2026VAEngine

   My 2019 Mazda CX-9 (VIN [XXX]) suffered catastrophic cylinder head failure on the SKYACTIV-G 2.5T engine at approximately 124,000 miles. The failure is consistent with Mazda TSB 01-013/21 (and successors 01-007/22, 01-010/24), in which Mazda acknowledged that cylinder heads on this engine can crack at the stud bolt hole and exhaust manifold flange due to manifold deformation and residual production stress. The first warning came in mid-May 2026, when the engine temperature…

   NHTSA complaint #11745033 · source
3. Filed Jan 31, 2026CAEngine

   - Coolant leak at cylinder head and turbo at only 63,000 miles. - Safety issue because no warning lamps or messages appeared and potential for car to overheat without coolant circulating in the system. Car could breakdown at worst time and location. Leaking coolant onto exhaust created potential for fire. - Problem has not been confirmed by dealer yet. Appointment is upcoming. - Symptoms of the problem were leaking coolant on ground, low coolant level, heater not working…

   NHTSA complaint #11714720 · source
4. Filed Sep 30, 2025FLEngine

   1. What component or system failed or malfunctioned, and is it available for inspection upon request? ANSWER: Engine failure due to overheating. 2. safety & indicators: ANSWER: During evening rush hour traffic on a 3 lane highway my car went into a form of engine power saving mode while i had children in the vehicle; this was almost catastrophic form my family and the other vehicles around me. there was NO warning. there were no previous issues with my vehicle, this was…

   NHTSA complaint #11690498 · source
5. Filed Jun 29, 2025PAEngine

   While driving on highway I get a message on my dashboard "High Engine Temperature/Engine Output may be limited" warning message. I pullover and see that the cooland is low. I wait for thee car to cool down and fill with coolant. After 5 minutes of driving, get the same message on dash. I had car towed to Martin Mazda in Delaware. Diagnosis is that I need a new EGR valve and new engine $13,000. How coincidental it has the same symptoms as described in TSB and manifests itself…

   NHTSA complaint #11670073 · source
6. Filed Mar 28, 2025COEngineSuspension

   Failed water pump, blown head gasket, major coolant leak, and warped head causing the vehicle to overheat and die when coming to a stop. Vehicle died when stopped in construction on a highway and we were nearly rear-ended. Vehicle never showed check engine light and temperature gauge never showed that vehicle was overheating but significant damage was caused to the engine from “excessive temperatures.” Failure of warning signals allowed us to continue driving the car with a…

   NHTSA complaint #11651264 · source
7. Filed Feb 27, 2025NCEngine

   Car coolant warning light came on for a short time 5 min after starting car, then would go off. During severely cold days it would come on then go off once the car was warm. On 2/25/25 the coolant warning light appeared and stayed on. The car made loud rickety noise, as it warmed up. After driving 2 miles the car coolant light turned red and began blinking. An alert appeared saying car over heating. The car was stopped and smoke came out of the car. The car leaked…

   NHTSA complaint #11645310 · source
8. Filed Jun 29, 2024CAEngineOther / Unknown

   I have a coolant leak that I have not been able to locate. Despite replacing the radiator, the leak persists. When I contacted the dealer to inquire about estimates for changing the water pump and timing chain, they advised that it would be more cost-effective to replace the entire engine, which would require removing the existing engine at a starting cost of $5,000, with a new engine costing approximately $6,000. They suggested that if I'm already experiencing issues, it…

   NHTSA complaint #11597741 · source
9. Filed Jun 13, 2024VAEngine

   2019 Mazda CX-9 Coolant Leak. 1st warning light just discovered on June 10, 2024. Dealership quoted not under warranty and will cost $14,000 to replace engine. Mazda has an open TSB Technical Service Bulletin for this and many other Mazda's with the same engine- TSB-Coolant Leaks at Cylinder Heads, Bulletin # - 01-013/21 issued 10/15/21 (CRACKED CYLINDER HEADS). Need Mazda to stand by their product and remedy impacted owners.

   NHTSA complaint #11594259 · source
10. Filed Jun 6, 2024CAEngine

    Started with rough idle then got overheating msg on dashboard. After the diagnostics they found cracked cylinder head and quoted $6000 for replacement. Called Mazda USA and they denied our claim. Car is under 5yrs old & around 74k. While working on the car they noticed the turbo needed it to be rebuilt. Another $2k. There is TSB out for this and it’s a known problem, lot of others having/had same issues. Never had a car that needed an engine replacement even before car is…

    NHTSA complaint #11592956 · source
11. Filed Jun 5, 2024VAEngine

    In June of 2022, Mazda issued a TSB for an engine flaw that cause coolant to leak in to the engine and significant overheating occurred. This overheating causes the head to warp. The TSB states that the only repair for this is a newer model engine. This happened to my Mazda CX9 and quite a few more. There are class action suits currently ongoing. Mazda never made its owners aware of the TSB. The car can shut down on the highway which is dangerous to all.

    NHTSA complaint #11592579 · source
12. Filed May 17, 2024CABrakesEngineFuel, Hybrid & EV Propulsion

    Have been making repairs back to back since I bought it had to do four oil changes within that year then tires were completely worn electrical problems kept freezing spark plugs completely burnt discs were really rust car automatically turned off even though the battery is still good and still had gas had that happen twice and did more of a history search in it has had more complaints before every time try to take it to Mazda always be something with their system

    NHTSA complaint #11589375 · source

Source: U.S. National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation public data. Complaints are submitted by owners and are not verified by NHTSA or by us; a complaint does not prove a defect exists. View this vehicle on NHTSA.gov Methodology