2017 Mazda CX-9: what breaks, and at what mileage
What breaks on the 2017 Mazda CX-9
On the 2017 Mazda CX-9, the failure owners report most often is head gasket failure, with 18 reports on file. Across every failure mode on this year, half the dated reports were filed before 35,000 miles. Overall it scores 73 out of 100, high risk for a 2017.
High risk for a 2017 — 151st riskiest of the 263 2017 vehicles we can rate. 78 owner reports; fleet size borrowed from other years of the same model.
The failures owners actually file about
Owners have reported 24 named failure modes on the 2017 Mazda CX-9, and the three most-reported carry 47% of everything filed.
Head gasket failure leads with 18 reports and about 0.7 per 1,000 vehicles.
Other engine problem follows with 11 reports.
Radiator or coolant leak follows with 8 reports.
By system, the reports fall mostly into engine (35), cooling (19) and body (5).
When these failures get reported
10 of the reports on the 2017 Mazda CX-9 came with an odometer reading, and half of those were filed before 35,000 miles.
Cumulatively, 70% by 50,000 miles of the dated reports had been filed.
The busiest stretch is between 30,000 and 40,000 miles, which alone holds 30% of the dated reports.
50% of the dated reports were filed below 36,000 miles, which is early enough that a fair number of these cars were still under a factory warranty when the owner complained.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
Showing the 12 most-reported failure modes of 24. The full list is in the table below.
How reports accumulate
Every report with an odometer reading, cumulative, from 0 to 200,000 miles. A curve that climbs early is a car with early problems, whatever its total.
- Line share of reports filed by that mileage
- Dashed the median reported mileage
Severity, and what it costs
Nothing in the reports on the 2017 Mazda CX-9 mentions a crash, a fire or an injury. That is the ordinary case and it is worth stating: most defect complaints are about a car that stopped working, not one that hurt somebody.
The average severity weight across every report on this year is 4.32, where a stalled engine or a failed airbag weighs many times more than a rattling trim panel, and a figure this high means the reports are dominated by failures with safety consequences rather than annoyances. The weighting is set out in full on the methodology page.
What the top failures cost to put right, as editorial estimates for an independent US shop rather than figures from NHTSA: head gasket failure at $1,400–$4,000, other engine problem at $300–$4,000, radiator or coolant leak at $350–$1,900 and overheating at $400–$3,500. Dealer labour, a seized bolt or a part that is no longer made can push any of these past the top of its range.
71% of the reports on this year sit in the engine, transmission, drivetrain or cooling systems — the four where a repair bill is usually four figures, so more than half of what owners complained about here is expensive.
Every reported failure mode
| Failure mode | System | Reports | With reading | 25th | Median | 75th | Per 1,000 | Typical repair | Severity |
|---|---|---|---|---|---|---|---|---|---|
| Head gasket failure | engine | 18 | 0 | — | — | — | 0.7 | $1,400–$4,000 | Critical |
| Other engine problem | engine | 11 | 0 | — | — | — | 0.5 | $300–$4,000 | High |
| Radiator or coolant leak | cooling | 8 | 0 | — | — | — | 0.3 | $350–$1,900 | High |
| Overheating | cooling | 4 | 0 | — | — | — | 0.2 | $400–$3,500 | High |
| Thermostat failure | cooling | 4 | 0 | — | — | — | 0.2 | $250–$900 | Moderate |
| Water pump failure | cooling | 3 | 0 | — | — | — | 0.1 | $500–$2,200 | High |
| Fuel pump failure | fuel | 3 | 0 | — | — | — | 0.1 | $600–$2,600 | High |
| Other suspension problem | suspension | 3 | 2 | — | 29k | — | 0.1 | $350–$2,000 | Moderate |
| Engine bay fire | engine | 2 | 0 | — | — | — | 0.1 | $4,000–$20,000 | Critical |
| Oil leak | engine | 2 | 0 | — | — | — | 0.1 | $250–$2,200 | Moderate |
| Sunroof failure or glass breakage | body | 2 | 0 | — | — | — | 0.1 | $700–$4,500 | High |
| Other wheel or tire problem | wheels | 2 | 2 | — | 49k | — | 0.1 | $200–$1,500 | High |
| Other driver assistance problem | adas | 2 | 0 | — | — | — | 0.1 | $250–$1,800 | High |
| Other body or interior problem | body | 2 | 2 | — | 64k | — | 0.1 | $200–$2,000 | Moderate |
| Misfire or rough idle | engine | 1 | 0 | — | — | — | 0.0 | $250–$1,600 | Moderate |
| Turbocharger or supercharger failure | engine | 1 | 0 | — | — | — | 0.0 | $1,500–$4,500 | High |
| Control module (ECM/PCM/BCM) failure | electrical | 1 | 1 | — | 40k | — | 0.0 | $700–$3,000 | High |
| Infotainment screen failure | infotainment | 1 | 0 | — | — | — | 0.0 | $400–$2,600 | Low |
| Seat belt or retractor failure | airbag | 1 | 0 | — | — | — | 0.0 | $200–$900 | High |
| Strut, shock or spring failure | suspension | 1 | 0 | — | — | — | 0.0 | $500–$2,000 | Moderate |
| Rust or structural corrosion | body | 1 | 0 | — | — | — | 0.0 | $500–$6,000 | High |
| Other powertrain problem | transmission | 1 | 1 | — | 34k | — | 0.0 | $400–$4,500 | High |
| Other brake problem | brakes | 1 | 1 | — | 45k | — | 0.0 | $300–$1,800 | High |
| Other visibility problem | glass | 1 | 1 | — | 18k | — | 0.0 | $150–$1,400 | Moderate |
| Unclassified problem | other | 2 | 0 | — | — | — | 0.1 | — | Moderate |
This year had no usable recall paperwork, so the fleet-size estimate is the median of other years of the same model. Repair costs are typical independent-shop ranges for the failure, not figures from these reports.
How often, against how many were built
Scaled by an estimate of how many of these cars exist, the 2017 Mazda CX-9 draws about 3.2 per 1,000 vehicles, which puts it in the 80th percentile of complaint rates among 2017 vehicles we can rate.
That denominator is the weakest number on the page and it is fair to say so plainly. This year had no usable recall paperwork, so the fleet-size estimate is the median of other years of the same model.
The working figure is 24,185 vehicles. If the true number is twice that, every rate on this page is half what it says; the ranking against other 2017 vehicles, which is what the risk score uses, is far more robust than the rate itself.
How it ranks in the 2017 field
The score at the top of the page, placed among its peers. The zones are the same thresholds the scorer applies, read out of the scorer itself, so the picture and the band word cannot disagree.
Scores are ranked within the model year, never across years, because an older car has had longer to accumulate reports.
- Left fewer and less serious reports
- Right more, or worse
- Marker this vehicle
Where 2017 sits in the model line
High risk for a 2017 — 151st riskiest of the 263 2017 vehicles we can rate. Every score on this site is a rank inside its own model year, which is what makes a 2004 and a 2019 comparable at all.
Across the 16 model years of this car that carry enough reports to score, 2007 comes out best at 64 and 2018 worst at 82, with 2017 itself at 73.
If the model year is negotiable, 2007, 2023, 2009, 2008 and 2014 score lower than 2017 by a margin worth acting on. Same body, same engines, different luck — usually a supplier change or a mid-cycle fix, which the complaint data can show but never explain.
Within the 2016–2020 generation specifically, 2017 is the strongest year at 73 and 2018 the weakest at 82.
Scores compare each year against other cars of the same model year, so a low number on an older car is a real result and not an artefact of age.
Shorter is better. Years with too few reports to score are shown without a bar rather than as a zero, because no data is not good news.
Within the 2016-2020 generation, 2017 Mazda CX-9 scores best at 73 and 2018 Mazda CX-9 worst at 82.
What this page cannot tell you
78 owner reports; fleet size borrowed from other years of the same model. Every count on this page is therefore a floor: it is the number of owners who went to the trouble of filing with a federal agency, which is a small and self-selected fraction of the owners who had the fault.
Of those 78 reports, 10 carried an odometer reading, so the mileages here describe 13% of the sample rather than all of it. Owners also round: readings pile up on multiples of ten thousand, which is why this site publishes "about 90,000 miles" and not "91,438".
The failure modes are assigned by software reading the owner's own words, which is accurate in bulk and wrong in individual cases. A mode with a handful of reports may contain a misfiled one.
And nothing here predicts what one car will do. These are other people's complaints, filed years apart, on cars maintained by strangers. Read the page as a map of where this model year has previously gone wrong, then have the specific car in front of you inspected.
Questions this page answers
What are the most common problems with the 2017 Mazda CX-9?
The most-reported failures are head gasket failure (18 reports), other engine problem (11 reports) and radiator or coolant leak (8 reports). Counts come from owner complaints filed with NHTSA, which are voluntary, so they show what owners bothered to report rather than every fault that occurred.
Is the 2017 Mazda CX-9 reliable?
It scores 73 out of 100 on our risk index, which is high — 151st riskiest of the 263 2017 vehicles we can rate. The score is a comparison against other 2017 vehicles, not a prediction about any individual car, and it is built from complaint rates, severity and how early failures appear.
Which year of the Mazda CX-9 is best?
Within the 2016–2020 generation, 2017 scores best at 73 out of 100 and 2018 worst at 82. Same body, same engines, different luck.
Where this comes from. Every figure above is computed from NHTSA owner complaints and recall records for this exact make, model and year. Complaints are voluntary and self-selected, so treat counts as a floor. The methodology page writes out each formula, and the same numbers are available as JSON.
What breaks at my mileage Compare with another car
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed