Thinking about buying a used Infiniti M (1986–2009) in New Zealand? We've documented 15 known faults for this model spanning electrical, engine, suspension, and transmission. Each researched and verified before it's published. The most serious issues here are rated critical. Two are set out in full below — the rest, with the symptoms, repair costs and checks for each, are free with an account.
15
Documented faults
Critical
Most serious
$644–$1,800
Typical repair
6
Systems covered
Known Infiniti M faults
Every fault below is documented specifically for this model — researched and verified before it’s published.
01Y51 Hybrid High-Voltage Battery Cell Imbalance and Degradation
CriticalCommonElectrical $4,000–$12,000 to fix
The Y51 Fuga Hybrid combines a VQ35HR 3.5L V6 with a 50 kW electric motor and a lithium-ion high-voltage battery pack. Individual battery cells degrade at different rates, causing voltage imbalance across the module. The battery management system attempts to compensate but eventually flags faults when cell spread exceeds tolerance. Advanced degradation reduces the pack's ability to accept regenerative charge or supply assist power, increasing fuel consumption and placing additional load on the combustion engine.
Symptoms to notice
Hybrid system warning light illuminated on the instrument cluster, accompanied by reduced or absent electric motor assist during acceleration
Fuel economy measurably worse than factory specification, and the battery state-of-charge indicator fluctuating erratically or dropping suddenly during light driving
What to check
Connect Nissan CONSULT-III Plus or a compatible hybrid scanner and read individual cell voltages across the battery modules — a spread greater than 0.3 V between the highest and lowest cell indicates imbalance requiring pack replacement. Check P3000-series hybrid fault codes. Inspect the battery cooling fan in the boot for blockage or motor failure, as thermal stress accelerates cell degradation.
Where to look: Boot floor beneath the luggage compartment load panel
Ask the seller
“Has the hybrid battery been tested for cell balance or capacity, and are there any outstanding hybrid warning lights?”
“What is the current real-world fuel economy compared to when the car was new?”
02Rear Wheel Bearing Failure
MajorCommonSuspension $336–$672 to fix
The rear wheel bearings on F31 Leopard are semi-floating and are prone to wear at high mileage. The sealed bearing units corrode internally from moisture ingress through degraded hub seals, producing a low growling drone that increases with vehicle speed and changes pitch on cornering. Continued use risks the bearing seizing, which in a semi-floating rear axle can cause the wheel to detach from the housing under torque.
Symptoms to notice
Abnormal tyre wear pattern
Fault codes or irregular readings when scanned
What to check
Check all bushes and ball joints for play. Look for oil leaks on shock absorbers. Measure tyre wear pattern across the tread. The rear wheel bearings on F31 Leopard are semi-floating and are prone to wear a...
Ask the seller
“::TEXT”
ElectricalCritical
EngineCritical
SuspensionMajor
TransmissionMajor
SuspensionMajor
EngineMajor
EngineMajor
BrakesMajor
SuspensionMajor
CoolingMajor
CoolingMajor
BrakesMajor
SuspensionMajor
13 more documented faults on the Infiniti M
Symptoms, what to check, where to look and what to ask the seller — for every fault above. Free with an account, no card needed. One account covers one vehicle, so make it the car you’re actually looking at.
This page covers the model. Enter the plate of the actual car you’re looking at and see its year, engine, safety rating and register flags — free, no account needed.
Like any used car, it depends on the specific example and its service history. Across the 15 documented faults for the Infiniti M, the recurring problem areas are electrical, engine, and suspension. A Infiniti M with a full service history and no signs of the issues listed on this page can be a sound buy but each one needs to be checked individually before you commit.
What are the most common problems with a used Infiniti M?
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We've catalogued 15 known faults for the Infiniti M, covering electrical, engine, and suspension. Two are written out in full on this page. The rest — with the symptoms to notice, what to inspect, and typical repair costs for each — are free once you create an account.
How much do repairs cost on a Infiniti M?
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Most single repairs on the Infiniti M fall between $644–$1,800 at NZ independent-workshop rates. Some of the 15 documented faults cost less and a few cost considerably more, and no one car needs them all. Knowing which ones to look for before you view is what lets you negotiate the price down or walk away.
Should I get a pre-purchase inspection on a Infiniti M?
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Yes. A Infiniti M inspection focused on its known weak points is the single best way to avoid an expensive mistake. KickTyres gives you a guided, model-specific inspection plus a market valuation and negotiation figure for $17.90 far less than the cost of missing one of the faults on this page.