The Infiniti G37 remains a popular used performance car because of its VQ37VHR V6, rear-wheel-drive platform and availability as a sedan, coupe or convertible. Most G37s are now old enough that maintenance history and previous repairs matter more than a simple model-year ranking. A properly maintained higher-mileage car can be a better purchase than a low-mileage example that has sat unused or been heavily modified.
The following concerns are commonly discussed by owners and specialists. They are not proof that every G37 will fail in the same way. Inspect the exact vehicle, check the VIN for recalls and review service records before buying.
Low Oil Pressure and Gallery-Gasket Concerns
One of the most discussed VQ37 concerns is low oil pressure that may be associated with internal oil-gallery gasket deterioration on some engines. The gasket is located behind the front timing cover, so diagnosis and repair can involve substantial labor. Symptoms may include an oil-pressure warning, related diagnostic codes, engine noise or measured pressure below specification.
A dashboard warning alone does not prove gallery-gasket failure. The oil level, oil specification, filter, pressure sensor and wiring should be checked, and actual pressure should be measured with suitable equipment. Do not continue driving a vehicle with confirmed low oil pressure.
Heater-Hose Connector and Coolant Leaks
A plastic heater-hose connector used in the cooling system can become brittle with age. Owners may notice a coolant smell, residue near the rear of the engine compartment, a low reservoir or a sudden leak. Infiniti’s official parts catalog lists the heater-hose connector as a service part used in G37 applications.
Inspect the connector, nearby hoses and clamps only when the engine is completely cool. Replacing the connector before it breaks may be sensible on an aging vehicle, but fitment should be confirmed by VIN. After cooling-system work, the system must be refilled and bled correctly.
Transmission and Driveline Behavior
The G37 was offered with automatic and manual transmissions, and AWD models add a transfer case and front driveline. An automatic transmission may feel firm during certain shifts, but delayed engagement, slipping, repeated harsh shifts or shuddering requires diagnosis. Do not assume that a fluid change will repair a mechanical or control problem.
Inspect for leaks and review whether the fluid has ever been serviced. The official maintenance guides call for periodic inspection and specify additional service under certain severe-use conditions. Manual-transmission oil, automatic-transmission fluid, transfer-case fluid and differential oil are separate products with different specifications.
Differential Bushing and Rear-Driveline Wear
A worn rear differential bushing is another frequent age-related complaint. Symptoms can include a thump when shifting between drive and reverse, movement during acceleration changes or visible fluid from a hydraulic-style bushing on applicable models. Other mounts, driveshaft components and suspension bushings can create similar noises.
A visual inspection on a lift helps identify excessive movement and leaking bushings. Upgraded bushings may sharpen response but can also increase noise and vibration, so the repair should match the owner’s priorities.
Steering Leaks and Misdiagnosis
Power-steering fluid around the steering rack should be diagnosed carefully. Infiniti issued service information explaining that assembly lubricant inside a steering-rack boot can be mistaken for a fluid leak. The bulletin directs technicians to inspect the color and source before replacing the steering gear.
A genuine leak can still occur from hoses, the pump or the rack. Low fluid, whining noise and heavy steering should be addressed promptly. Use the correct power-steering fluid and do not hold the steering against full lock for extended periods.
EVAP Codes and Fuel-System Warnings
A check-engine light with an EVAP small-leak code may be caused by a loose fuel cap, damaged hose, canister problem or sealing fault. Infiniti service information for several models describes a P0456 leak at the vent-control-valve O-ring and instructs technicians to replace the seal rather than the entire valve when the diagnosis confirms that condition.
A smoke test and scan-tool procedure are more reliable than replacing parts at random. EVAP faults usually do not create dramatic drivability problems, but they can prevent the vehicle from passing emissions inspection.
Sunroof Drains and Water Intrusion
Water inside the front footwell, damp carpet or electrical problems after rain may involve a blocked or disconnected sunroof drain, windshield leak, door seal or body seam. Water can damage connectors and control modules long before the carpet appears soaked.
Check for dampness under the carpet and inspect drain outlets without using excessive air pressure that could disconnect a hose. Water-intrusion diagnosis should reproduce the leak carefully rather than soaking electronic areas.
Suspension, Brakes and Tires
G37 suspension components, wheel bearings and brake hardware wear with age. Listen for clunks over bumps, humming that changes with speed, brake vibration and uneven tire wear. Sport models may use staggered tires that cannot be rotated front to rear.
Modified suspension and aggressive wheel fitment can create rubbing, poor alignment and rapid inner-tire wear. Inspect the inside edge of every tire, not only the visible outer tread.
Convertible-Specific Concerns
G37 convertibles add a complex retractable hardtop, additional seals and drainage paths. Operate the roof through a complete cycle and listen for abnormal sounds. Check the trunk divider, warning messages, hydraulic components and evidence of water intrusion.
Roof repairs can be expensive and require specialized knowledge. A convertible should not be purchased with an inoperative top based only on the seller’s claim that it needs a simple sensor.
Used G37 Buying Checklist
Begin with a cold start. Listen for abnormal engine noise, check warning lights and confirm that the idle stabilizes. During the road test, evaluate transmission engagement, steering, braking and vibration at highway speed. Test the air conditioning, windows, seat controls, audio, navigation and every convertible function where equipped.
Inspect service records for oil changes, coolant work, spark plugs, transmission and driveline service. Scan all modules, check the VIN for recalls and arrange a pre-purchase inspection. The best G37 is usually the car with the strongest maintenance history, not necessarily the newest badge or lowest advertised mileage.
Primary references checked: INFINITI manuals and guides | INFINITI recall lookup | NHTSA recalls and service documents