Infiniti G37 Reliability Over 100000 Miles

The Infiniti G37, lauded for its potent VQ37VHR engine, luxurious features, and engaging driving dynamics, occupies a sweet spot in the used car market. However, like any vehicle approaching or exceeding 100,000 miles, potential buyers – and current owners – rightly ask: how reliable is it?

A Deep Dive into G37 Reliability at Higher Mileage

Assessing the reliability of a car with significant mileage requires a nuanced approach. We can't simply rely on aggregated customer satisfaction scores (though these can be helpful). A comprehensive understanding necessitates examining the individual components and systems that contribute to overall vehicle health, particularly those known to be potential weaknesses.

The Heart of the Matter: The VQ37VHR Engine

The 3.7-liter VQ37VHR engine is arguably the G37's strongest asset. This naturally aspirated V6, renowned for its smooth power delivery and responsiveness, is generally considered robust. However, even the most reliable engines have potential vulnerabilities as they age. Let's explore them:

Oil Consumption: This is perhaps the most commonly cited issue. While not universally experienced, some VQ37VHR engines exhibit increased oil consumption as the mileage climbs. This can stem from worn piston rings, valve stem seals, or even the positive crankcase ventilation (PCV) system. Regular oil level checks are crucial. If you notice excessive consumption (more than 1 quart per 1,000 miles), a compression test and leak-down test are recommended to pinpoint the cause. Addressing this early can prevent more severe engine damage.
Timing Chain Tensioners: The VQ37VHR utilizes a timing chain, which, unlike a belt, is designed to last the life of the engine. However, the tensioners that maintain proper chain tension can wear or fail over time. Listen for a rattling noise, especially at startup, as an early warning sign. Replacing the tensioners proactively, while not a simple task, is far less expensive than repairing a damaged engine resulting from timing chain failure.
Gallery Gaskets: Located within the engine, these gaskets are responsible for sealing the oil passages that feed the variable valve timing (VVT) system. Over time, they can degrade and leak, leading to oil pressure loss. Low oil pressure can severely impact engine performance and longevity. This is a more complex repair, often requiring significant engine disassembly.
Cooling System: While not exclusive to the VQ37VHR, maintaining a healthy cooling system is paramount. Check for coolant leaks at hoses, the radiator, and the water pump. Overheating can cause catastrophic engine damage. Regularly flush and replace the coolant according to the manufacturer's recommendations. Consider upgrading to a higher-quality radiator and silicone hoses for improved reliability.

Beyond the Engine: Drivetrain and Transmission

The G37 was offered with both a 7-speed automatic transmission and a 6-speed manual transmission. Each presents its own set of reliability considerations:

7-Speed Automatic (RE7R01A): This transmission is generally considered reliable, but proper maintenance is key. Regular fluid changes (every 30,000-60,000 miles depending on driving conditions) are essential. Neglecting this can lead to shifting problems, slipping, and eventually, transmission failure. Listen for any unusual noises or harsh shifting. A transmission fluid analysis can provide valuable insights into the transmission's health.
6-Speed Manual: The manual transmission is typically more robust than the automatic. However, clutch wear is inevitable, especially with spirited driving. Listen for clutch slippage, difficulty shifting, or unusual noises when engaging the clutch. Also, check the condition of the clutch master and slave cylinders for leaks. Synchro wear can also occur with high mileage, leading to grinding when shifting gears.
Differential: The differential transfers power from the transmission to the wheels. Listen for whining noises from the rear of the vehicle, which could indicate worn bearings or gears within the differential. Regular fluid changes are recommended.
Driveshaft: Inspect the driveshaft for any signs of damage or wear, particularly the universal joints (U-joints). Worn U-joints can cause vibrations and eventually fail, leading to loss of power.

Suspension and Steering

The G37's suspension and steering components are subject to wear and tear over time, affecting handling and ride quality:

Shocks and Struts: Worn shocks and struts can lead to a bouncy ride, poor handling, and increased braking distance. Replace them as needed. Consider upgrading to performance-oriented shocks and struts for improved handling.
Control Arms and Bushings: Control arm bushings provide a pivot point for the suspension. Worn bushings can cause clunking noises, poor alignment, and imprecise handling. Inspect them regularly and replace them as needed.
Ball Joints: Ball joints allow the wheels to move up and down and steer. Worn ball joints can cause play in the steering, clunking noises, and even separation, which is a serious safety hazard. Inspect them regularly and replace them as needed.
Power Steering System: Check for leaks in the power steering pump, hoses, and rack. Low power steering fluid can cause noisy operation and difficulty steering. A failing power steering pump can be a costly repair.

Electrical System

Modern vehicles rely heavily on their electrical systems. While generally reliable on the G37, some areas warrant attention:

Battery: Batteries typically last 3-5 years. Have the battery tested regularly, especially in extreme climates.
Alternator: The alternator charges the battery and provides power to the electrical system. A failing alternator can cause a dead battery and other electrical problems.
Sensors: Numerous sensors monitor various engine and vehicle parameters. Faulty sensors can trigger the check engine light and affect performance. Diagnosing and replacing faulty sensors is essential.
Wiring Harnesses: Inspect the wiring harnesses for any signs of damage or corrosion. Damaged wiring can cause a variety of electrical problems.
Electronic Components: The G37 has various electronic components, such as the infotainment system, climate control system, and power windows. These components can fail over time.

Body and Interior

Cosmetic condition aside, the body and interior can also reveal clues about the vehicle's history and maintenance:

Rust: Inspect the body for any signs of rust, especially in areas prone to corrosion, such as the wheel wells, rocker panels, and undercarriage.
Interior Wear: Check the condition of the seats, carpets, and trim. Excessive wear can indicate heavy use or poor maintenance.
Electronics: Ensure that all the interior electronics, such as the power windows, door locks, and climate control system, are functioning properly.

Mitigating Risks and Ensuring Longevity

While the G37 possesses inherent strengths, proactive maintenance is paramount to maximizing its lifespan beyond 100,000 miles. Here's a summary of key recommendations:

Prioritize regular maintenance: Adhere to the manufacturer's recommended maintenance schedule, and even consider shortening intervals for critical items like oil changes and transmission fluid flushes, especially if the vehicle is driven hard.

Address issues promptly: Don't ignore warning signs like unusual noises, fluid leaks, or changes in performance. Addressing problems early can prevent them from escalating into more costly repairs.

Thorough pre-purchase inspection: If purchasing a used G37, have it inspected by a qualified mechanic who is familiar with the VQ37VHR engine. A compression test, leak-down test, and thorough visual inspection can reveal potential problems.

In conclusion, the Infiniti G37 can be a reliable vehicle beyond 100,000 miles, provided it has been properly maintained and potential issues are addressed proactively. By understanding the G37's strengths and weaknesses, and by following a diligent maintenance regimen, owners can enjoy its performance and luxury for many years to come.