Quick answer: Spark Plug Replacement on a 2007–2013 GMC Sierra 1500 is rated Advanced and takes about 2–3 hours. You'll need 5 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 the gasoline/ICE engine in 2007-2013 GMC Sierra; 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
Locate the coils and plug wires
The 2007–2013 Sierra 1500 is the GMT900 generation, offered with the 4.3L V6 or the 4.8L, 5.3L, 6.0L, or 6.2L V8. Instead of coil-on-plug, these engines use individual coils bolted to the valve covers, each connected to its spark plug by a short plug wire with a metal heat shield around the boot. Open the hood with the engine stone cold: on a V8 you'll see four coils per side, and the rear two on each side hug the firewall — those are the tough ones. Gather a ratchet with sockets (including 7mm), long extensions, a 5/8-inch spark-plug socket with a rubber insert, spark-plug boot pliers, a feeler gauge, dielectric grease, and a new set of plug wires.
2
Clear access — no intake removal needed
No intake removal is needed on these trucks — everything is reachable from the sides. If your truck has an engine cover, lift it off. Blow loose dirt away from the coil and wire area before disturbing anything.
3
Disconnect the battery
Loosen the negative battery cable clamp with a 10mm wrench, lift the cable off the post, and tuck it aside so it cannot spring back onto the terminal. You will lose radio presets and the clock, and the transmission may shift differently during a short relearn drive afterward.
🔧 Mechanic's note — Tom Becker
I tuck the loose cable behind the battery hold-down — if it springs back onto the post while your hands are down in the plug wells, you'll know about it.
4
Remove the coils and plug wires
Lift the locking tab on each coil's electrical connector and unplug it, then remove the two small hold-down bolts (7mm) securing each coil and set the coil aside. Now the plug wires: grasp each BOOT with spark-plug boot pliers, twist to break the heat-baked seal, and pull the boot off the plug — these wires seize onto the plugs, and yanking the wire itself will tear the boot or pull the terminal apart. That's why you're replacing the wire set: plan on new wires with every plug change on these trucks. Keep everything in order as you go.
5
Remove the old spark plugs
Blow compressed air down each plug well before removing plugs. Seat a 5/8-inch spark-plug socket with a rubber insert onto your extension and loosen each plug counterclockwise, lifting it straight out.
6
Gap-check and install the new plugs
Use the iridium plug type specified for your engine in the owner's manual. Check each new plug's gap with a wire-style feeler gauge against the specification in the manual or on the underhood emissions sticker; adjust gently with a proper gapping tool if needed, and never pry on the center electrode of an iridium plug. Thread every plug in by hand with just the extension (no ratchet) until it turns freely — this is especially important for the rear plugs you can't see — then seat each plug per the plug manufacturer's instructions. Overtightening strips the aluminum head. Use anti-seize only if the plug maker calls for it; most iridium plugs install dry.
🔧 Mechanic's note — Tom Becker
I've learned the hard way — Don't learn this the expensive way: Use anti-seize only if the plug maker calls for it; most iridium plugs install dry.
7
Reassemble wires, coils, and shields
Route the new plug wires exactly as the originals ran and press each boot firmly onto its plug until you feel it seat over the plug terminal — a wire that looks connected but isn't fully clicked on is the classic cause of a post-job misfire. Refit the metal heat shields over the boots, remount each coil with its two 7mm bolts, and reconnect the electrical connectors until they click. Reinstall the engine cover if your truck has one, and double-check that every connector is seated and no tools are left on the engine.
8
Verify the repair
Reconnect the battery and start the engine — the V8 should idle dead smooth with no shake or check-engine light. Watch for misfire codes (P0300–P0308).
All Done!
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
- • Yanking plug wires by the wire and tearing the boot — twist and pull the boot with pliers instead.
- • Not fully seating the new wires onto the plug terminals, causing a misfire under load on the test drive.
- • Cross-threading a rear plug by starting it with the ratchet in a blind hole — hand-start with the extension alone.
