Nissan 4.0L VQ40DE Engine Specs, Problems, Reliability, Info

Nissan 4.0L VQ40DE V6 Engine Overview

The 4.0-liter naturally aspirated V-shaped six-cylinder Nissan VQ40DE engine was first introduced in 2004. It is a member of the VQ engine family and, to put it simply, is a stroked version of the 3.5-liter VQ35DE engine. The VQ40DE engine was manufactured at Nissan's Decherd Powertrain Plant in Tennessee and used in vehicles like the Nissan Frontier, Xterra, Pathfinder, and Suzuki Equator. This 4.0-liter V6 engine features all the DNA of VQ series, including an aluminum block and DOHC heads, continuous VVT, a variable length intake system, and produces between 261-276 horsepower and 281-294 pound-feet of torque, depending on the year and application. Let's take a closer look at the design of the VQ40DE engine and learn about its specifications, reliability, longevity, and common problems.

4.0L V6 VQ40DE Engine Features

The heart of this engine is a lightweight aluminum, open-deck style cylinder block with cast iron sleeves and 60-degrees cylinder angle. This block is similar to the VQ35DE/VQ35HR block, but it has a taller height for a longer 92mm stroke (the deck height is around 244mm). The block is fitted with a forged crankshaft, forged connecting rods, and moly coated aluminum pistons.

The engine came with aluminum DOHC cylinder heads with four valves per cylinder, sized valve tappets (it requires a valve adjustment every 60k miles), and platinum-tipped spark plugs. Camshafts are driven by chains. There are three chains in total: the main timing chain and two small camshaft chains (one inside each cylinder head). Intake camshafts have phase adjusters of the Nissan's Continuous Variable Valve Timing Control System (CVVTCS). Camshaft specs: 240/244 duration (intake/exhaust), 0.394 in. (10.0mm)/0.478 in. (9.6mm) valve lift (intake/exhaust). Valve covers are made of plastic.

The Nissan VQ40DE engine is equipped with a conventional port fuel injection system. The intake system consists of two parts: a lower intake manifold and an upper intake manifold. The lower intake manifold is made of aluminum alloy, while the upper part is plastic. The upper intake manifold has the ability to change its geometry (length/volume). In 2013, the intake was updated with a new, lower aluminum plenum that has electronically controlled valves to improve combustion efficiency. The stock VQ40DE throttle body (drive-by-wire) has a 70mm bore diameter. The ignition system is quite modern, featuring individual coils (coil-on-plug design) and durable platinum-tipped spark plugs. It is also worth mentioning that certain 2017-2018 Nissan models with the 4.0L V6 engine, specifically the Nissan Frontier, are Flex-Fuel capable (can run on E85 fuel).

The VQ40DE engine was used by Nissan until 2024. The third-generation Nissan Frontier pickup truck (2020+) received a new 3.8-liter V6 engine with gasoline direct injection, code named VQ38DD.

Engine Specs

The Most Common VQ40DE Engine Problems

The 4.0L VQ40DE engine has earned a reputation for being a capable and reliable workhorse. However, like any VQ-series engine, the VQ40DE is not immune to problems and failures that can affect its performance and longevity. While the VQ40DE is generally dependable, owners have reported several common problems.

• Timing Chain Tensioner Failure: One of the most common issues, especially in models from 2007 to 2012. A faulty tensioner can cause rattling noises from the engine due to timing chain slack and misalignment. If left unaddressed, it can lead to more severe engine damage.
• Oil Consumption: Increased oil consumption is a common problem. This often occurs due to worn piston rings or valve seals. The scratches on the cylinder walls can also be a factor. Bad fuel can damage the catalytic converter and cause its dust to enter the engine, scratching the walls and potentially causing further damage.
• Oil Leaks: Oil leaks from worn valve cover gaskets and spark plug tube seals are very common.
• Variable Valve Timing Problems: The VVT system needs a good clean engine oil. Poor maintenance and infrequent oil changes typically lead to the failure of the VVT solenoid or actuator.
• Overheating: The cooling system of this engine is not great, and if something goes wrong, the engine can easily overheat. Cooling fan coupling failure is a common issue. Engine overheating can also be caused by a low coolant level or a dirty radiator.

Nissan 4.0 V6 VQ40DE Reliability and Longevity

The VQ40DE is generally considered reliable and robust engine. It is a dependable power source for pickups and SUVs with a good balance of power and durability that, with proper maintenance, good engine oil, fuel and filters, can last way over 200,000 miles. There are many Nissan vehicles with 4.0-liter V6 engines that have reached the 350,000-mile mark.