2.5L DOHC Skyactiv-G Engine Complete Assembly for 2021-2024 Mazda 3, CX-30

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

• Check the 8th digit of your vehicle's VIN. It must be Y. If it is M or L, you have the naturally aspirated version, and this engine will not fit.
• Confirm whether your vehicle is Front-Wheel Drive (FWD) or All-Wheel Drive (AWD) to determine if you need to swap the oil pan and transfer case brackets.
• Physically inspect your original turbocharger, wastegate actuator, and exhaust manifold to ensure they are in good, reusable condition to transfer.

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

Special tools this job needs:

• Mazda MZR/Skyactiv Timing Tool Kit (camshaft alignment plate and crankshaft TDC timing peg)
• Fuel Injector Seal Installer/Sizer Tool
• Engine hoist and load leveler
• Bi-directional scan tool

Budget for these consumables at install:

• 5.1 US quarts (4.8 Liters) of SAE 5W-30 API SN/SP or ILSAC GF-6 engine oil
• New OEM Mazda oil filter (Part # 1WPE-14-302 or equivalent)
• Mazda Genuine FL22 Extended Life Coolant (pre-diluted 55/45)
• New OEM NGK Iridium spark plugs (gapped to 0.028-0.031 in / 0.7-0.8 mm)
• Intake manifold gasket
• Exhaust manifold gasket
• Turbocharger inlet/outlet gaskets and oil feed/drain line copper washers
• Valve cover gasket (if removed)
• Fuel injector Teflon seals (must be replaced if injectors are removed)
• New OEM turbocharger oil feed and return lines
• New OEM torque-to-yield bolts (crankshaft pulley bolt, cylinder head bolts)

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

What’s involved: Crankshaft Position (CKP) Sensor Relearn and Fuel Injector Calibration

If you reuse your original ECU/PCM, you do not need to reprogram the immobilizer. However, you must perform a CKP sensor relearn so the ECU can accurately detect misfires. Additionally, if you use the direct fuel injectors that come with this replacement engine, you must program the injector calibration codes into your ECU. To avoid this programming step, you can transfer your original injectors to this replacement engine in their exact original cylinder positions.

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

• Friction-Fit Crankshaft Pulley (No Keyway): The crankshaft pulley does not have a keyway. You must NEVER loosen the crankshaft pulley bolt without the proper Mazda timing alignment tools installed, or the engine will instantly slip out of time and cause catastrophic valve-to-piston contact.
• Direct Injector Teflon Seals: Direct injectors use one-time-use Teflon seals. If you pull the injectors, you must use a special sizing tool to compress the new Teflon seals before installing them, or they will leak compression and fuel.
• AWD vs. FWD Oil Pan and Intermediate Shaft: If your vehicle is AWD and this engine was configured for a FWD model (or vice versa), you must swap the oil pan and the intermediate shaft mounting brackets to clear the transfer case (PTU).
• Torque-to-Yield (TTY) Bolts: The crankshaft pulley bolt, cylinder head bolts, and certain suspension/subframe bolts are stretch bolts and must never be reused.
• Turbocharger Transfer: Because this unit ships without the turbo, you must transfer your original turbocharger and exhaust manifold. Replace the turbo oil feed line with a new OEM part to prevent starving your turbo of oil.
• Plastic Intake and Boost Pipes: The plastic intake manifold and charge pipes become brittle from heat cycling. Handle them carefully during the swap to avoid cracking them.
• AWD PTU (Transfer Case) Alignment: Transferring the Power Take-Off Unit (PTU) requires careful alignment and fresh spline grease to avoid post-install gear oil leaks.

Easy to get right once you know them:

• Reusing the Crankshaft Pulley Bolt or loosening it without the proper timing tools.
• Mixing up fuel injectors or failing to program their calibration codes into the computer.
• Using non-FL22 coolant, which can react with residual coolant and create a gel-like sludge.
• Forgetting to transfer AWD-specific brackets and oil pan from the original engine.
• Reusing old metal gaskets or oil feed lines on the transferred turbocharger.
• Using 0W-20 oil instead of the required 5W-30 oil for the Turbo variant.
• Skipping the PCM/CKP relearn, leading to rough idling, misfires under boost, or check engine lights.

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: