4.0L V6 DOHC Engine Complete Assembly for 2019 Nissan Frontier - Upper

A quick look at your own vehicle makes sure the right engine shows up:

• Check your VIN's 4th digit: Look at the VIN plate on your dashboard or driver's side door jamb sticker. Confirm that the 4th digit of your VIN is 'A'.
• Verify your transmission type: Confirm that your truck has an automatic transmission.
• Compare the upper oil pan: Look under your current truck and compare your upper oil pan's shape and differential mounting points to the photos of the unit we are selling. Because swapping the VQ40DE upper pan requires splitting the crankcase, you want to ensure they match exactly before ordering.

What the install really takes — plan and budget with confidence:

Special tools this job needs:

• VQ40 Ring Gear Stop (Nissan Essential Tool J-48761)
• Engine hoist/crane with a load leveler
• Fuel line quick-disconnect tool
• Swivel sockets and long 1/2" drive extensions
• Nissan camshaft holding tools (if doing timing work)
• High-end bi-directional scan tool for idle relearn

Budget for these consumables at install:

• Engine Oil & Filter (Fresh OE-spec 5W-30 synthetic engine oil and a high-quality oil filter)
• Engine Coolant (Fresh Nissan Blue Long Life Antifreeze/Coolant or equivalent 50/50 pre-diluted blue coolant)
• Spark Plugs (Six fresh OE-spec platinum or iridium spark plugs, NGK or Denso)
• Intake manifold plenum gaskets (upper and lower)
• Throttle body gasket
• Exhaust manifold gaskets (if exhaust manifolds are transferred)
• Thermostat and thermostat housing gasket
• PCV Valve (Fresh OEM Nissan PCV valve)
• RTV Sealant (High-quality RTV silicone such as ThreeBond 1217H or Permatex Ultra Grey)
• Timing Chain Kit (Primary/secondary chains, tensioners, and guides - highly recommended while the engine is out)
• Oil Gallery Gaskets (Upgraded metal gallery gaskets to replace the factory paper ones)
• Rear main seal
• Valve cover gaskets

What your vehicle’s computers will need after the swap:

What’s involved: Idle Air Volume Learning, Throttle Valve Closed Position Learning, and Accelerator Pedal Released Position Learning

While the engine itself does not require a dealer scan tool to "re-marry" the ECU to the vehicle, you must perform the standard Nissan electronic throttle body relearn procedures if the throttle body or accelerator pedal harness is disconnected or replaced. This consists of three specific timed key-on/key-off and pedal-press sequences. These relearn procedures can be performed manually using a stopwatch and precise timing, though a professional scan tool makes the process much easier and more reliable.

Pro tips for a smooth first start-up — hand them to whoever does the install:

• Tricky Transmission Bellhousing Bolts: The top two transmission bellhousing bolts are extremely difficult to access. The best method is to use a 3-foot extension with a swivel socket, reaching up from behind the transmission crossmember.
• Upper Oil Pan Variations: The upper oil pan design can vary between years and drivetrain configurations (2WD vs. 4WD). On the VQ40DE, the upper oil pan is structural and integrates with the main bearing caps/girdle. It is not a simple stamped-steel pan. Swapping it requires splitting the lower crankcase and meticulous resealing with Nissan RTV.
• Fragile Knock Sensor Harness: The knock sensor is located deep in the "V" of the engine block under the intake manifold. The wiring harness for the knock sensor becomes extremely brittle from engine heat and is highly prone to cracking or breaking during an engine swap. Inspect this harness carefully and replace it if it shows any signs of wear before installing the intake manifold.
• Crankshaft Position Sensor Shield: When transferring or installing the crankshaft position sensor, make sure the water shield boot and metal shield are properly seated. Dropping the small 10mm shoulder bolt into the bellhousing is a common nightmare; use a magnetic socket to prevent this.
• Gallery Gasket Replacement: Do not drop this engine in without replacing the rear timing cover oil gallery gaskets. It is a massive job in the truck, but very straightforward on an engine stand.
• SMOD (Strawberry Milkshake of Death) Check: Before hooking up the new engine, check your radiator. If the internal transmission cooler failed, it mixes coolant and ATF. This will destroy your transmission and can severely overheat your new engine.
• Heater Hose Inlet: The plastic heater hose inlet on the firewall side of the engine becomes extremely brittle. It is very easy to snap during the swap.

Easy to get right once you know them:

• Buying for the Wrong VIN Code: You must verify the 4th digit of your vehicle's VIN. The 2019 Frontier has two different 4.0L V6 engine options: VIN A and VIN D. This engine is specifically for VIN A. Ordering this engine for a VIN D vehicle will result in compatibility issues with the wiring harness and ECU calibration.
• Using Aftermarket Cam/Crank Sensors: A massive failure point is using aftermarket camshaft and crankshaft position sensors. You must use ONLY OEM Nissan or Hitachi-branded sensors.
• Reusing the PCV Valve and Hoses: Many buyers swap the engine but reuse the old, clogged PCV valve. This causes high crankcase pressure, which quickly blows out the fresh valve cover gaskets, leading to oil leaks and oil consumption. Always install a new OEM PCV valve.
• Failing to Perform the Throttle Relearn: After the swap, many experience a surging or extremely high idle (often throwing code P0507) because they failed to perform the three-step Nissan throttle relearn procedure.
• Ignoring the Timing Components on the Stand: Buyers often regret not doing the chains, guides, and gallery gaskets while the engine was easily accessible on the stand.
• Breaking Sensors During Install: The crankshaft position sensor and camshaft position sensors are easily bumped and cracked when mating the engine to the transmission.
• Reusing Old Coil Boots: Reusing oil-soaked ignition coil boots from a previous valve cover leak will cause immediate misfires on the replacement engine.

Not issues with the units on this page — the manufacturer documented these for every engine of this family, wherever you buy one. Handy for your installer: