Quick answer: Spark Plug Replacement on a 2019–2024 GMC Sierra 1500 is rated Advanced and takes about 1-3 hours. You'll need 4 tools for this job, and parts cost about $115. This guide walks you through the full job step by step, including the mistakes to avoid.
| Part Name |
Part Number |
Price |
Buy |
| Correct spark plug set for 2019-2024 GMC Sierra 1500; verify engine, heat range, gap, and VIN fitment |
— |
$115.00 |
|
| Coil-boot seals or ignition coils only if inspection finds damage Optional |
— |
$35.00 |
|
About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.
💡 Pro tip: Order all parts at once to save on shipping
Step-by-Step Instructions
Follow these steps carefully
1
Confirm engine and plug fitment
The 2019-2024 Sierra 1500's 5.3L L84 V8 (with Dynamic Fuel Management) takes the ACDelco 41-110 iridium — the NGK-made OE plug (ILTR5E11) — pre-gapped at 0.040 in (1.025 mm). You need eight. Note the tight 0.040 gap: it's smaller than the previous-generation 5.3's 0.060, so don't substitute plugs gapped for an older truck. The iridium OE plug is a ~100,000-mile plug, and DFM trucks are sensitive to weak spark — a shudder or misfire under light load often traces back to worn plugs. Scan for misfire codes before ordering.
🔧 Mechanic's note — Ray Delgado
That 0.040 gap is the detail that matters — the old 5.3s ran 0.060, and parts counters will happily sell you those. I check the box for 41-110 before I leave the store; the wrong gap runs rough on a DFM truck.
2
Cool and expose the plugs
Disconnect the negative battery cable. The rearmost coils near the firewall are the tightest, particularly on the passenger side under the cowl, so stage a 5/8 in (16 mm) spark plug socket with a rubber insert, a 6-inch extension, and a universal joint first.
3
Remove the coils
Work one side at a time. Squeeze each coil connector's locking tab and pull it straight back without pulling the wiring. Remove the single coil bolt and lift each coil straight up, keeping them in cylinder order on a rag.
4
Remove and install plugs
Remove each old plug with the 5/8 in (16 mm) spark plug socket, turning counterclockwise. Verify the 0.040 in gap on every new plug even though they're pre-gapped; never pry on the fine iridium center electrode.
5
Reconnect and verify
Press each coil firmly onto its plug until it seats, refit the coil bolts, and reconnect every connector until the tabs click — then tug-test each one. Reconnect the negative battery cable. Start the Sierra and confirm a smooth idle with no flashing check-engine light.
🔧 Mechanic's note — Tom Becker
The DFM light-throttle cruise is my real test drive — that's where I've learned a weak coil shows itself as a shudder when cylinders deactivate, and idling in the driveway won't find it.
All Done!
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
- • Using the wrong plug or assuming a pre-gapped plug needs no verification
- • Blowing debris into an open cylinder or plug well
- • Cross-threading a plug or tightening it without a torque wrench
- • Overusing anti-seize or dielectric grease on the plug threads
- • Mixing coil connectors or ignoring a misfire after reassembly
