Reliability report · 2019 Mazda CX-9 · Updated July 2026
The 2019 sits at the turning point. The cracked-cylinder-head coolant leak that defined 2016-2018 still appears in the file, but the year is quieter, and an independent mechanic specifically calls the 2.5-liter turbo 'more reliable from 2019 plus' as Mazda's running changes took hold. The leak is still covered by CSP11 — a Customer Service Program extending the powertrain warranty to 10 years or 120,000 miles for exactly this repair.
Two recalls apply. 21V875 (Mazda 5321K) replaces a Denso low-pressure fuel pump whose impeller can crack and stall the engine. 19V770 (Mazda 4019J) covers only 2019 CX-9s fitted with specific Falken ZIEX CT50 tires (size P255/50R20, date code 1619) whose tread can separate — a narrow, date-code-limited campaign, but confirm it. This is a Chirping year: inspect the engine for coolant loss, confirm CSP11 status, and clear both recalls by VIN.
Evidence: 51 NHTSA complaints · 2 recall campaigns · 7 mechanic & forum sources
Canary status
Chirping
What that means: 51 federal complaints, still engine-led but noticeably quieter than 2016-2018. The 2.5-liter turbo's cracked-cylinder-head coolant leak persists and remains covered by Mazda's CSP11 warranty extension (10 years/120,000 miles). Two recalls sit alongside — the fuel pump and a specific tire-tread defect. A good used year: known issues, mostly covered, verify.
51
Federal complaints
2
Recalls
$0 (covered)
If CSP11 window applies
several thousand
Cylinder-head repair if outside CSP11 (owner/mechanic reports)
Ranked by the cost of ignoring them. Every claim carries its source.
Still the most consequential issue, though the 2019 file is thinner than the peak years. The 2.5-liter turbo's cylinder head can crack behind the exhaust manifold and leak coolant, leading to overheating and, untreated, engine damage. Mazda's CSP11 extends the limited powertrain warranty to 10 years or 120,000 miles for this repair (with reimbursement), and it covers 2019. A mechanic source notes the engine grew more reliable from 2019, but the leak has not fully disappeared from the data — inspect for coolant residue at the back of the block and confirm whether the head was replaced and CSP11 still applies.
What to check
Pink and cleanServiced. Proceed.
Dark brownDamage underway.
Cylinder-head repair if outside CSP11 (owner/mechanic reports)
several thousand
If CSP11 window applies
$0 (covered)
Sources: NHTSA complaint database, 2019 Mazda CX-9 · NHTSA recalls + manufacturer communications (21V875, 19V770, CSP11 windows, campaign documents) · Independent mechanic and owner/specialist channel transcripts (CX-9 second generation, 2.5T)
Recall 21V875 (Mazda 5321K) covers 2018-2019 CX-9 (among several Mazda models): the impeller in the Denso low-pressure fuel pump can crack and deform, causing the pump to fail and the engine to stall. Free fuel-pump replacement; owner letters mailed July 18, 2022. Confirm completed by VIN.
Sources: NHTSA recalls + manufacturer communications (21V875, 19V770, CSP11 windows, campaign documents)
Recall 19V770 (Mazda 4019J) is narrow: only 2019 CX-9s equipped with Sumitomo Falken ZIEX CT50 A/S tires, size P255/50R20 104V, date code 1619, whose tread can separate and detach — a stability/crash risk. The remedy is a free inspection and replacement as needed; the recall began December 4, 2019. Because it hinges on a specific tire date code, confirm by VIN whether the car was affected and remedied. Separately, the i-ACTIVSENSE driver aids (Smart Brake Support / adaptive cruise) can false-activate — test them on the drive.
Sources: NHTSA complaint database, 2019 Mazda CX-9 · NHTSA recalls + manufacturer communications (21V875, 19V770, CSP11 windows, campaign documents)
By 2019 the cracked-head file is thinning, and a mechanic source calls the 2.5 turbo 'more reliable from 2019 plus' — but the coolant leak still shows, and CSP11 still covers it.
Free fixes at any Mazda dealer. Run the VIN — “completed” isn’t always completed.