Model years › Mazda CX-9

2017 Mazda CX-9

This year drew an ordinary 61 complaints for a Mazda CX-9 — the model's median is 68. What they were about is the unusual part: 42.6% of them mention cylinder head, against 0% across the model's other years.

NHTSA opened a defect investigation into this model year.

What the complaints were about

• cylinder head — 42.6% of this year's complaints, against 0% across the model's other years (213.1×).
• coolant — 55.7% of this year's complaints, against 6.2% across the model's other years (9.1×).
• engine — 68.9% of this year's complaints, against 14.5% across the model's other years (4.8×).

Words owners used for the same problem are counted together, so a fault written four different ways is measured once. Grouped by which complaints they appear in, not by a list anyone wrote in advance.

What owners wrote

coolant leaks from cracked cylinder head which cause the car to overheat and have the engine stalled on the highway.

Coolant Leak at Cylinder head. There is a known TBS01-013/21 They refused to pay for any of the cost to replace the engine. My out of pocket cost was $10K.

Verbatim from NHTSA complaint filings, with identifying details removed.

Own a 2017 Mazda CX-9? What happened to yours?

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How this was worked out

Every year of the Mazda CX-9 was compared against its own history rather than against other cars, which removes popularity and age from the answer — a common car draws more complaints at equal reliability, and an older one has had longer to accumulate them. A year is flagged when it drew at least 2.5× this model's median and at least 50 complaints.

This is a fault record, not a review. Nobody files a federal complaint to say the car was fine, so it shows what tends to go wrong — not whether owners liked it, and not whether it is a good car.

Source: NHTSA complaints, recalls and investigations, retrieved . Look this vehicle up directly on NHTSA's site to check anything here.

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