What reliability score does the Mazda CX-9 get?

5.7 out of 10, scored from the 8 faults we document for this model and how severe each one is.

Is the 2016–2023 Mazda CX-9 reliable?

Scored from 8 documented faults · reviewed by the VehicleFaults Research Team

Quick answer

5.7/ 10

Mixed

On our documented-fault scoring the Mazda CX-9 rates 5.7 out of 10 · mixed. We hold 8 known faults for it and 1 are rated high severity, so the risk is real but contained. The weak points cluster around engine, cooling and brakes. A well-serviced example with evidence for the big-ticket items is usually a safe buy; the score describes the model, not the specific car in front of you.

Verdict · Negotiate · budget for the known faults

What the score is built from

Critical: 0
High: 1
Medium: 5
Low: 2

Weak points cluster around engine, cooling, brakes, electrical.

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The faults that decide it

EngineHigh

Coolant leak from a cracked cylinder head near the exhaust manifold.

Typically appears: 40,000-80,000 miles
What to inspect: Open the bonnet, check the coolant expansion tank level, and shine a torch down the back of the engine near the exhaust manifold for dried white or pink coolant crust.
Typical repair: Head gasket / cooling system repair · £900–£2,600

EngineMedium

2.5T carbon build-up on intake valves.

Typically appears: 60,000+ miles
What to inspect: Watch for rough idle / hesitation; ask about any walnut-blast cleaning.
Typical repair: Routine repair · £180–£700

CoolingMedium

Internal (chain-driven) water pump wear.

Typically appears: 80,000+ miles
What to inspect: Check for coolant loss; note the labour-intensive replacement.
Typical repair: Head gasket / cooling system repair · £900–£2,600

BrakesMedium

Brake booster faults.

Typically appears: Age-related
What to inspect: Test pedal feel and scan for codes.
Typical repair: Brakes (discs, pads, caliper) · £200–£800

SuspensionMedium

Creaking or clunking noises from the front suspension over bumps due to worn lower arm bushes or top mounts.

Typically appears: 50,000-70,000 miles
What to inspect: Push down firmly on the front wings to check for top mount creaks, then apply full steering lock left and right while stationary to listen for bush groans.
Typical repair: Suspension refresh (per axle) · £250–£1,100

Costs are indicative UK independent-garage bands for budgeting and negotiation · never a quote.

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Quick answer

What the score is built from

The faults that decide it

Inspecting a Mazda CX-9?

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