Owners have filed 35 complaints with NHTSA about this car, most about the engine, airbags, and transmission. The 9 checks below target those problems, in the order you would do them at the car.
2021Tick items off on your phone at the car, or print it. Ticks stay on this device.
0/9 checked
2021 Mazda CX-9: inspection sheet
Before you go, or before you touch the car0/3
Ask the seller not to warm the car up first0/3
At least 20 minutes, with some highway0/3
These checks are specific to this model year. For tires, body panels, fluids, and the other basics every used car needs, use the general inspection guide.
These years share the 2021's design and most of its parts, so their problems are the ones to look for on this car too.
Worth adding to your 2021 checks
Worth adding to your 2021 checks
Worth adding to your 2021 checks
EPA figures for each version of the 2021 Mazda CX-9. Use them to confirm you are looking at the version that was advertised, and as a yardstick on the test drive.
| Version | Drive | EPA rating |
|---|---|---|
| 2.5L 4-cyl | 4WD, FWD | 23–24 mpg |
Owners report these failures starting around the mileages below. A car inside one of these ranges deserves a closer look at that part, or records showing it was already fixed.
Low oil warning, oil burning
6,700–18,900 miles
NHTSA complaints for the 2021 Mazda CX-9, grouped by the part owners named. Open a row to read what goes wrong.
Burning oil is the dominant complaint. The low oil warning comes on well before the scheduled change, often with a quart gone every 2,500 to 4,000 miles, and some cars run 2 quarts low. Dealers blame defective valve stem seals. Several owners say the fix was slow, disputed, or did not stop the oil use. A smaller group of reports describes more serious trouble: stalling at highway speed, a misfire code that won't clear, and rapid loss of both oil and coolant.
Both complaints follow crashes. In one, the driver's front airbag did not deploy in a frontal collision at 10 to 20 mph, and the car shut down afterward. In the other, the right curtain airbag broke the rear grab handle and roof hook into sharp pieces that flew through the cabin. Only two reports are on file, but both concern how well occupants are protected in a crash.
Two very different failures appear. One crash report, with an injury, describes the car lurching forward and accelerating on its own while the driver was reversing into a parking space. It hit a tree and was a total loss. The other describes a cylinder losing compression at about 60,083 miles. The dealer and Mazda declined to pay because the valve stem seal settlement covers only oil consumption repairs. The owner links the damage to carbon buildup from oil burning.
A crash report describes the brakes letting go about a second into a hard stop. The car rolled into a stopped vehicle, and the phone app then showed a Brake System Malfunction message. The other complaint is about clicking and squeaking brakes that keep coming back. New brakes and rotors at around 22k miles did not fix it. The dealer's service bulletin fix, brake grease, quiets the noise only for about a month.
Excerpts from complaints CX-9 owners filed with NHTSA, as written. Listen for the same symptoms on your test drive.
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.
Filed with NHTSA, April 2023
New Mazda vehicle engine is consuming approximately 1 quart of oil, approximately every 3,500 miles. No recall for this yet, however Mazda technical service bulletin TSB # 01-012/21 admits this is a common and known issue for this vehicle which may eventually lead to the vehicles engine and parts no longer functioning.
Filed with NHTSA, July 2022
2021 Mazda CX-9 Frontal collision at a speed between 10-20 mph. Car shut down after collision and was not drivable. Concern is the driver side airbag did not deploy. (Neither did passenger but there was no person in the passenger seat)
Filed with NHTSA, May 2023
Complaints for this year next to the average for the other model years, area by area.
The 2021 ranks third for owner complaints among 6 CX-9 years, close to the average of the others. Newer years have had less time to collect complaints, so compare like with like.
Redesigns and mid-cycle updates change what can go wrong.
The 2021 is the sixth model year of the CX-9's second generation (2016–2024).
Recall repairs are free at any Mazda dealer, but the seller may never have had them done. Check each campaign number against the VIN.
Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may unexpectedly slide forward during a crash. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 210, "Seat Belt Assembly Anchorages.".
Risk: A seat that slides forward during a crash can transfer excessive force onto a belted occupant, increasing their risk of injury.
Fix: Dealers will replace the internal parts of the affected second-row seats, free of charge. Owner notification letters were mailed November 4, 2021. Owners may contact Mazda customer service at 1-800-222-5500, Option 4. Mazda's number for this recall is 5221I.
Cars shoppers compare with the Mazda CX-9, with their own 2021 checklists.
2021 owner complaints, side by side
