What are the common issues with the VQ35 engine?

[StMatthew]

vq35 engine common issue is oil burning. Causes of oil burning: Carbon deposits: Carbon deposits accumulate in the piston grooves, causing the piston rings to stick together, significantly reducing the oil-scraping and sealing capability. Valve stem seal corrosion and aging: Corrosion and aging of the valve stem seals result in poor sealing. Front and rear crankshaft seal aging: Continuous exposure to oil and temperature variations inside the engine gradually weaken the sealing effectiveness of the front and rear crankshaft seals, leading to oil seepage or leakage. Air filter clogging: This restricts airflow, reducing intake pressure and creating a vacuum, which draws oil into the combustion chamber under negative pressure, causing oil burning. PCV valve clogging or damage: When the oil-gas mixture solidifies and enters the intake tract through the PCV pipe, it leads to increased oil consumption. Dirty throttle body: This allows unfiltered air to enter the throttle body directly, resulting in oil burning.

[Robert]

The VQ35 engine has indeed caused some minor issues for quite a few owners. I've driven several Infiniti vehicles equipped with this engine and found that oil burning is a major problem. The piston ring design flaw leads to excessive oil consumption, requiring about half a liter of top-up every 1,000 kilometers, which keeps me frequently checking the dipstick. Additionally, the valve cover gasket tends to age and leak oil, especially under high temperatures, dripping onto the engine cover and necessitating a gasket replacement. Ignition coil failures are also common, particularly after driving 70,000 to 80,000 kilometers, when the coil packs are prone to malfunction, causing engine shaking and sluggish acceleration. When the timing chain tensioner ages and the chain loosens, it creates a loud rattling noise that can be quite annoying. To mitigate these issues and extend the engine's lifespan, it's advisable to use high-quality synthetic oil and adhere to regular oil change intervals without exceeding the recommended mileage. While the car performs decently, these minor problems can become quite frustrating if neglected. Timely maintenance and inspection of key components are crucial.

[SanMaddox]

Having worked in the repair shop for several years and serviced many VQ35 engine models, oil burning is a common issue mainly due to poor piston ring sealing, with high-mileage vehicles experiencing severe oil consumption. Valve cover gasket leaks are also quite frequent, and the rear cover is the most difficult to replace, requiring significant effort. The ignition coils have a high failure rate, potentially causing one or two to fail around 50,000 kilometers, leading to cylinder misfires and vibrations—it's easier to replace the entire set. The timing chain tensioner ages, causing the chain to loosen and produce loud noises; sometimes, it skips teeth and damages the engine, so early intervention is necessary. Some catalytic converter clogging issues are mostly caused by oil burning, leading to poor exhaust flow and sluggish acceleration. For these situations, I recommend owners check for oil leaks every six months, using high-temperature-resistant sealant and synthetic oil. Preventive maintenance is much more cost-effective than major repairs after a breakdown, and the vehicle remains reliable overall, though it tends to have minor issues frequently.

[VonHarper]

The VQ35 engine is considered a classic among Japanese cars, but it has several common issues. Oil burning is prominent due to insufficient piston ring design, leading to faster oil consumption and affecting performance. Valve cover leaks are common, with aged seals causing dripping that's hard to clean. Ignition coil failures occur frequently, sometimes causing misfires and vibrations after just tens of thousands of kilometers. Over time, the timing chain tensioner may loosen, creating noise, and chain issues require timely replacement. Other problems, like occasional oil pump jamming, are frequently discussed in forums, with car enthusiasts sharing experiences on regular filter changes and using high-quality oil. With proper maintenance, minor issues are manageable, and the engine remains powerful and fuel-efficient, making it worth the effort.