2.5L DOHC 16-Valve Engine Complete Assembly for 2015 Nissan Altima - Front

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

• Check your VIN's 4th Digit: Look at the 17-digit VIN plate at the base of your windshield or on the driver's side doorjamb. Confirm that the 4th digit is the letter 'A'.
• Verify your Engine Code: Locate the engine ID stamp on the front of the engine block. It should read 'QR25' or 'QR25DE'.
• Confirm your Drivetrain: Confirm that your vehicle is Front-Wheel Drive (FWD). If you are attempting to install this engine into an All-Wheel Drive (AWD) Nissan Rogue, be prepared to transfer your original oil pan, brackets, and intermediate shaft.

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

Special tools this job needs:

• Engine hoist and load leveler
• External Torx Plus EP20 socket
• Professional OBD-II Scan Tool (capable of initiating Nissan-specific idle air volume learning and crankshaft position relearns)
• Subframe support jacks

Budget for these consumables at install:

• 5.1 quarts of 0W-20 fully synthetic engine oil
• New OEM-spec spin-on oil filter
• Nissan Blue Long Life Antifreeze/Coolant (50/50 pre-diluted)
• 4 new Laser Iridium spark plugs (NGK DILKAR6A11 or equivalent)
• Intake manifold gasket set
• Exhaust manifold gasket
• Thermostat gasket
• Rear main seal
• New OEM-spec thermostat
• Nissan NS-3 CVT Fluid

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

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

No security/immobilizer re-marriage is required for a bare engine swap as long as you retain your original ECM. However, because the throttle body is disconnected and swapped, you must perform the three standard Nissan throttle relearn procedures to prevent a surging or high idle (P0507 code). These can be done manually using a precise ignition key/pedal timing sequence, or instantly using a compatible scan tool. If you experience a check engine light with code P1336 (Crankshaft Position Variation Not Learned) or random misfires after the swap, a crankshaft position variation relearn must be performed using a professional diagnostic scan tool.

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

• The A/C Compressor Shortcut: You do not need to disconnect or discharge your A/C system to swap this engine. You can unbolt the A/C compressor from the engine block and secure it to the vehicle's frame/radiator support out of the way.
• Flexplate Bolt Pattern: Torque converter bolt patterns can vary slightly between different model years and transmission variants. Always compare the donor engine's flexplate to your original. If they differ, you must swap your original flexplate onto the new engine using an EP20 External Torx Plus socket.
• Sensitive Nissan Sensors: Do not use the camshaft or crankshaft position sensors that ship on the donor engine. Transfer your original, known-good OEM sensors to the replacement engine to avoid immediate diagnostic codes (P0335, P0340) or no-start issues.
• Torque-to-Yield Head Bolts: If you perform any internal work or replace the head gasket on this engine before installing it, remember that the cylinder head bolts are Torque-to-Yield (TTY) and cannot be reused.
• The PCV Valve Check: Before dropping the new engine in, check the color of the PCV valve. If it is orange, replace it with the updated black OEM Nissan valve to avoid false P0101 MAF sensor codes.
• CVT Transmission Fragility: The Jatco CVT8 (RE0F10D) bolted to this engine is notoriously prone to failure. Since you have to drop the engine and transmission together, this is the absolute best time to service the CVT by changing the NS-3 fluid and replacing the external transmission filter.
• Rusty Exhaust Fasteners: The bolts connecting the exhaust manifold to the rest of the exhaust system are prone to severe rust. Soak them in penetrating oil well in advance of the swap, and have replacement hardware ready.

Easy to get right once you know them:

• Buying the Wrong Year Variant: Assuming any 5th-generation (2013–2018) Altima 2.5L engine is a direct drop-in swap. If you buy a 2013–2014 engine or a 2016–2017 engine for your 2015 Altima, you must strip it down to the bare block and transfer your original manifolds, brackets, and sensors.
• Failing to Perform the Throttle Relearn: Assuming the engine is ready to drive immediately. If you don't perform the Idle Air Volume Relearn after reconnecting the throttle body, your Altima will suffer from a surging, erratic, or dangerously high idle (P0507 code).
• Neglecting the CVT Fluid and Cooler: Ignoring the CVT transmission while it is out. You must flush the external transmission cooler lines and replace the external oil cooler filter. Always use genuine Nissan NS-3 CVT fluid; using standard ATF or NS-2 will destroy the transmission immediately.
• Reusing a degrading exhaust manifold: Failing to inspect the inside of your old exhaust manifold (pre-cat) before bolting it to this replacement engine. If you reuse a bad pre-cat, the engine will suck that abrasive dust back into the cylinders and destroy your new piston rings in a matter of miles.

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: