2021 Mazda CX-9 engine problems

Related recalls

No recalls on file.

What owners say

1. Filed Aug 10, 2026IACrashTowedEngineAcceleration & Cruise ControlTransmission & Drivetrain

   The vehicle was parked stationary in the driveway with the engine running for 3-5 minutes with the A/C on. The vehicle then accelerated forward into my garage causing damage. Once I entered the vehicle, both the dash and shifter displayed park. Current TCU system internal failures have been reported from the pulling of data from Mazda.

   NHTSA complaint #11755863 · source
2. Filed Jul 23, 2026RIEngine

   1) What component or system failed or malfunctioned: On 6/12/2026 While drive on the highway with our daughter in the car and we experienced a high speed stall. The engine failed and we lost power. We barely got the car of the highway and coasted into a parking lot. 2) Life threating for Father, Mother and daughter and other drivers on the highway. 3) The Mazda dealer stated they were unable to reproduced problem. The diagnostic report showed few random misfired on two…

   NHTSA complaint #11752508 · source
3. Filed Jul 12, 2026VAEngine

   This complaint refers to Mazda and it's dealer refusal to properly execute the warranty work under the SSPD5 Valve Stem Seal Class Action Campaign and does not follow the Court's approval of the final Settlement Agreement. I assert that Mazda and it's dealer are not following the SSPD5 repair procedures. 1. I have documentation and complaints going back to Dec-2023 with this particular dealer that I have experienced low level oil consumption within the 7,500 mile oil change…

   NHTSA complaint #11749820 · source
4. Filed Jun 18, 2026MAEngine

   Check engine light comes on and error P0303 comes on. Had an independent mechanic do the following and after each one, error P0303 still came on 1. Swap the ignition coils from 2 to 3 2. Swap spark plugs from 2 to 3 3. Swapped injectors 4. Compression test 5. Leak down test 6. Changed the spark plug, coil and injectors 7. Looked for vacuum leaks. Mechanic believes that it is related to the cracked cylinder head in the recall, MC-10232269-0001.pdf. My vehicle is just outside…

   NHTSA complaint #11745150 · source
5. Filed Aug 14, 202453,186 miTXEngineAcceleration & Cruise Control

   The contact owns a 2021 Mazda CX-9. The contact stated that while accelerating quickly and entering the highway, there was no motive power to the vehicle. While crossing the highway in the right lane, driving at 65 MPH, the vehicle in front moved over; there was a parked vehicle. The contact was able to stop the vehicle before causing a crash. The driver was starting to accelerate, but there was no motive power when the accelerator pedal was depressed. The smart brake system…

   NHTSA complaint #11608556 · source
6. Filed Jun 20, 2024FLEngine

   Consumes over 2 quarts of oil between recommended oil changes. The dealer made excuses about needing to use a different oil but it has not improved the problem. The warning light for low oil went off after less than 3000 miles. It was 2 quarts down.

   NHTSA complaint #11595406 · source
7. Filed Jan 2, 2024FLEngine

   I just purchased this vehicle 2 months ago. Yesterday my oil light came on, I pulled over and checked the oil it was completely low. I had to put a quart of oil in it. After that I did some research and learned this seems to be an issue with some 2021 models the cx9 included. There needs to be a recall on this and Mazda needs to fix this issue. These cars cost way to much to have to put a quart of oil every month.

   NHTSA complaint #11563032 · source
8. Filed Apr 14, 2023VAEngine

   the vehicles experience excessive oil consumption because the defective valve stem seals allow engine oil to leak into the combustion chambers. This concern usually occurs when the mileage reaches approximately 2,000 – 3,000 miles (5,000 - 7,500km) and may also occur again after replacing or topping off the engine oil.

   NHTSA complaint #11517004 · source
9. Filed Feb 13, 2023VAEngine

   2021 Mazda CX-9 Low Oil Light came on at around 18,900 miles (2/10/2023 and 2/11/2023). Took to Mazda, and they said there was defective valve stem seals that can allow oil to leak into the engine’s combustion chamber. Vehicle is currently with Mazda service department to be fixed.

   NHTSA complaint #11506904 · source
10. Filed Feb 6, 202349,000 miTXEngine

    The contact owns a 2021 Mazda CX-9. The contact stated that while driving at 60 MPH or exceeding 60 MPH, the vehicle would lose motive power and stall without warning. The contact stated that he would coast to the side of the road and the vehicle would restart after 2-3 attempts and regain normal functionality. The vehicle had not been diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 49,000.

    NHTSA complaint #11505764 · source
11. Filed Nov 13, 2022PAEngine

    My 2021 Mazda CX-9 uses excessive engine oil as reported in the Mazda "M-Tip" bulletin MT-005/20 and this manufacturer's defect is reportedly caused by defective valve stem seals as claimed in the class action lawsuit U.S. District Court for the Central District of California, Southern Division: [XXX] v. Mazda Motor of America, Inc. The valve stem seal problems allegedly cause excessive oil consumption between regular oil change intervals, which increases the risk of engine…

    NHTSA complaint #11493358 · source
12. Filed Oct 20, 2022MAEngine

    1000 miles before first ever oil change was needed (according to window sticker provided by Mazda) the low engine oil light came on. The oil was low and needed to be toped off and brought directly to dealer for oil change. The same thing happened again 1300 miles before second oil change was required. It became obvious that the brand new vehicle was burning oil for some reason. The dealership tried to tell us that it was because the car was a turbo. We weren’t buying it and…

    NHTSA complaint #11490237 · 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