5.3L V8 L84 Engine Complete Assembly for 2019-2021 Chevrolet & GMC

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

• Verify the 8th digit of the VIN is 'D'.
• Confirm the RPO code 'L84' is listed on the build specification sticker or QR code.
• Confirm transmission type (8-speed vs 10-speed automatic) to determine if the flexplate, wiring harness brackets, or starter index plate must be swapped.

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

Special tools this job needs:

• GM Engine Prelubricator (EN-45299 or equivalent)
• GM Fuel Injector Remover/Installer Tool (EN-51146)
• Crankshaft Balancer Puller/Installer (EN-51264)
• Bi-directional Scan Tool (GM MDI, high-end Autel, Snap-on, or GM GDS2)

Budget for these consumables at install:

• Engine Oil: 8.0 quarts of SAE 0W-20 full synthetic oil meeting GM dexos1 Gen 3 (or Gen 2) specifications
• Oil Filter: ACDelco PF63 or WIX WL10255
• Coolant: GM-approved Dex-Cool (50/50 pre-diluted)
• Spark Plugs: ACDelco Iridium spark plugs (pre-gapped)
• Gaskets: Intake manifold gaskets, exhaust manifold gaskets, water pump gaskets, rear main seal, oil pan gasket, and valve cover gaskets
• High-Pressure Fuel Feed Pipe (one-time-use crush seals)
• Torque-to-Yield (TTY) Fasteners: Harmonic balancer bolt and exhaust manifold bolts
• Thermostat and Gasket

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

What’s involved: Crankshaft Position (CKP) Variation Relearn (CASE Relearn)

Whenever the engine is replaced, a Crankshaft Position System Variation Learning Procedure is mandatory. Failure to perform this will cause rough idling, inaccurate misfire detection, and trigger a flashing Check Engine Light with codes P0300, P0315, or P1336. Additionally, the vehicle's anti-theft system (Passkey) may need to be relearned.

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

• Critical Engine Prelubing: The engine must be prelubed using a pressurized oil tank before installing accessory drive belts and starting to prevent dry startup bearing damage.
• Inspect Rear Exhaust Manifold Bolts First: Extract any broken bolts from the cylinder heads while the engine is on the stand before installation.
• Fragile DFM Connector: The main wiring connector for the DFM solenoids at the back of the engine block is easily crushed against the firewall during installation.
• Oil Pan and Pickup Tube O-Ring: If transferring the oil pan or pickup tube, use a brand-new, perfectly seated and lubricated O-ring to prevent low oil pressure.
• High-Pressure Fuel System: Follow specific procedures for de-pressurizing the system and ensuring leak-free connections.
• Harness Chafing Inspection: Inspect the main engine harness for chafing near the control arm and shock tower areas before dropping the engine in.

Easy to get right once you know them:

• Reusing the High-Pressure Fuel Lines: Reusing these one-time-use crush joint lines can cause engine bay fires.
• Underfilling the Oil: The L84 requires exactly 8.0 quarts of oil, unlike older 5.3L engines that took 6.0 quarts. Underfilling causes immediate oil starvation to the DFM lifters.
• Assuming a Bad Engine Due to False Misfire Codes: Skipping the Crankshaft Position Variation Relearn will cause a flashing Check Engine Light and P0300 code.
• Reusing Stretched TTY Bolts: Reusing the harmonic balancer or exhaust manifold bolts can cause them to back out or snap.
• Ignoring the DFM Lifter Issue: Buying a 100k+ mile engine without being aware of potential future lifter failures.
• Not Swapping the ECM: Attempting to use the donor vehicle's ECM instead of reusing the original vehicle's ECM, which is programmed to the VIN and security system.

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: