The Infiniti I35 uses a timing chain, not a belt. The car’s 3.5-liter V6 (VQ35DE) employs a chain-driven timing system that is designed to last the life of the engine. That said, chain systems rely on tensioners and guides that can wear over time and may require service if symptoms arise.
In this article, we explain how the I35's timing system works, what that means for maintenance, and how to recognize signs of wear. Understanding the difference between belt and chain systems helps you plan service intervals and avoid unexpected engine trouble.
Timing mechanism in the Infiniti I35
The I35 uses a timing chain instead of a belt, which generally reduces the need for scheduled replacement in routine maintenance. Here are the key points you should know:
- The engine is the Nissan/Infiniti VQ35DE 3.5-liter V6, which uses a timing chain to synchronize the camshafts with the crankshaft.
- There is no fixed mileage interval for a timing chain like there is for most timing belts; the chain is designed to last much longer, though tensioners, guides and the water pump can wear over time.
- When performing major front-end service (for example, replacing the water pump, timing cover work, or replacing the drive belt system if applicable), many mechanics inspect or replace the chain tensioner and guides to prevent future problems.
- Common symptoms of chain-related issues include chain noise (rattle from the front of the engine), mis-timing, or valve timing concerns, though these are less common than belt failures on other platforms.
- Owners should follow the vehicle’s maintenance schedule and seek a professional assessment if they hear unusual noises or notice performance issues, especially at higher mileage.
In short, the Infiniti I35 relies on a timing chain rather than a belt, offering durability but requiring attention to the surrounding components as the vehicle ages.
Maintenance considerations for the VQ35DE timing chain
Because the timing chain is driven by the VQ35DE, practical maintenance focuses on the related components and the front-end service that often coincides with chain access.
- Inspect tensioners, guides, and the chain for wear during major service intervals or when accessing the timing area.
- Replace ancillary components (such as the water pump) when the timing area is opened or during significant maintenance to avoid a separate future job.
- Use OEM or manufacturer-approved parts for chain-related components to maximize longevity and reduce risk of premature wear.
- Listen for unusual engine noises and monitor timing-related performance issues, and consult a qualified technician if symptoms appear.
These steps help protect the engine and maintain reliability without the need for unnecessary belt-style maintenance.
Summary
The Infiniti I35 uses a timing chain, not a belt. While the chain is designed for long life, keeping the chain tensioners, guides, and related components in good condition—especially during major service—helps ensure longevity and prevents unexpected failures. Always refer to the owner’s manual and work with a trusted mechanic for maintenance decisions based on your mileage and driving conditions.