1.2L Turbo I-3 DOHC Engine Complete Assembly for 2025-2026 Buick & Chevrolet

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

• Verify your VIN's 8th Digit: Look at the VIN plate on your dashboard or driver's door jamb. The 8th digit must be 2 (for the LIH engine) or P (for the LBP engine). If the 8th digit is L, you have a 1.3L engine, and this engine will not fit.
• Confirm FWD Drivetrain: Verify that your vehicle is Front-Wheel Drive (FWD). This engine is not compatible with All-Wheel Drive (AWD) models.
• Check the Emission Label: Look at the Vehicle Emission Control Information (VECI) label under your hood to confirm your engine displacement is 1.2L.
• Inspect Your Turbocharger: Ensure your original turbocharger is undamaged and free of shaft play or oil contamination before planning to transfer it to this replacement engine.
• Check your RPO code: Look at the Service Parts Identification (SPID) sticker (usually located in the glovebox or driver's door jamb) and verify it lists LBP or LIH.

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

Special tools this job needs:

• EN-52455 (Thin-head open-end wrench)
• EN-52433 (Fuel injector removal tool)
• EN-52434 (Rear crankshaft seal installer)
• EN-52432 (Front cover crankshaft seal installer)
• GM GDS2 or equivalent bi-directional scan tool
• GM-specific wet timing belt locking tools (if servicing timing belt)

Budget for these consumables at install:

• Engine Oil: Must use full synthetic oil meeting GM dexos1 Gen 3 specifications
• Oil Filter: OE-spec AC Delco spin-on filter
• Coolant: GM-approved Dex-Cool (50/50 pre-diluted)
• Spark Plugs: New OE-spec iridium spark plugs
• Gaskets & Seals: Intake manifold gaskets, exhaust manifold gasket, thermostat seal, turbocharger mounting gaskets, and turbo oil feed/return line seals

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

What’s involved: Crankshaft Position (CKP) Sensor Variation Learn & ECM Software Update

A Crankshaft Position (CKP) variation relearn is mandatory whenever the engine is replaced. Additionally, the ECM must be checked and flashed with the latest software to address the Auto Stop/Start ignition timing recall (A242435780) to prevent damaging the replacement engine. If a new or used ECM is installed, full VIN-specific programming via GM's Service Programming System (SPS2) is required.

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

• Clean the Head Bolt Holes (Critical): If you remove the cylinder head or loosen any head bolts, you must use compressed air and lint-free cloths to completely dry and clean the bolt holes in the block. Any leftover oil, coolant, or debris will cause hydraulic lock when you torque the bolts, instantly cracking the aluminum block and ruining your engine.
• Rear Main Seal Lip Roll: When installing the rear engine cover, you must use the special guide tool EN-52434. Installing the cover without this tool frequently rolls the delicate inner lip of the crankshaft seal, creating a severe oil leak that requires removing the transmission to repair.
• Drop the Oil Pan First: Before installing any used 1.2L engine, you should drop the oil pan and physically inspect the oil pump pickup screen. If the donor vehicle had neglected oil changes, rubber debris from the wet timing belt may already be clogging the screen. Cleaning this screen on the stand is cheap insurance against immediate oil starvation.
• Turbocharger Transfer: Because this unit ships without the turbo, you must transfer yours. You must use new oil feed line gaskets and prime the turbo with fresh oil before starting the engine. Reusing old, clogged feed lines will kill the turbo instantly.
• Software Update is Mandatory: Do not skip the ECM programming. If your vehicle hasn't had Recall A242435780 performed, the old software can cause engine knock after an auto-stop event and destroy this replacement engine.
• Evap Purge Solenoid: Since this part fails frequently on the 1.2L, swap it out for a new OEM unit while the engine is easily accessible.

Easy to get right once you know them:

• Ordering for an AWD Vehicle: This 1.2L engine is exclusively used in Front-Wheel Drive (FWD) models. If your Trailblazer or Encore GX is All-Wheel Drive (AWD), your car uses the larger 1.3L engine. This 1.2L engine will not bolt up or connect to your AWD drivetrain.
• Reusing Torque-to-Yield (TTY) Fasteners: The crankshaft pulley bolt, camshaft sprocket bolts, and cylinder head bolts are 'stretch' bolts designed for one-time use. Reusing these bolts will cause them to back out or snap, leading to catastrophic engine failure. Always purchase brand-new TTY fasteners.
• Using the Wrong Engine Oil: Many DIYers and independent shops use generic bulk oil. On this engine, using non-dexos1 Gen 3 oil will cause the wet timing belt to rapidly disintegrate, clogging the oil pickup screen and seizing the engine within a few thousand miles.
• Reusing a Damaged Turbocharger: Since this engine is sold without a turbocharger, you must transfer your old one. If your original engine failed due to oil starvation or metal debris, your old turbocharger is likely contaminated and damaged. Installing a compromised turbocharger will instantly send metal debris into your replacement engine, destroying it.
• Confusing the 1.2L and 1.3L: Make sure you actually need the 1.2L. Buyers sometimes order this engine to replace a blown 1.3L because they look similar and are used in the same vehicle models. The 1.3L uses a timing chain and a 9-speed automatic; the 1.2L uses a wet belt and a 6-speed. They do not interchange.
• Skipping the CKP Relearn: Failing to perform the Crankshaft Position relearn will result in a Check Engine Light, misfire codes, and poor running conditions.
• Reusing Turbo Gaskets: Trying to reuse the metal gaskets when transferring your turbocharger almost always results in exhaust leaks or oil leaks.

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: