Quick answer: Spark Plug Replacement on a 2004–2008 Acura TSX is rated Advanced and takes about 1–2 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 the gasoline/ICE engine in 2004-2008 Acura TSX; 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
Prep — find the plugs on the K24A2
2.4-liter K24A2 i-VTEC: four iridium plugs under four coil packs across the valve cover, beneath the center cover. Some left the factory with two NGK and two Denso plugs — a mix is normal. Work cold, battery disconnected.
🔧 Mechanic's note — Ray Delgado
In my experience, If your old plugs are a mix of NGK and Denso, don't worry — that's how some of these left the factory. Replace them with one matched brand, though; mixing brands on the new set invites uneven wear.
2
Access — remove the center coil cover
Plastic center cover — held by clips and small fasteners — lifts straight up to expose the four coil packs (short connector, one hold-down bolt each). No intake parts, braces, or cowl panels come off.
3
Coil pack removal — press the tabs and lift
Press the locking tab down, slide the connector back — work driver's side to passenger side, keeping order. Remove each 10mm hold-down bolt, pull the coil straight up with a gentle twist. Pencil-style coils crack if tilted — lift vertically.
4
Plug removal — socket, extension, patience
Blow or vacuum debris from plug tubes first — grit must not fall into the cylinder. Use a 16mm plug socket on a long extension, spin out by hand. Compare all four: one oily/sooty while others are tan means investigate.
🔧 Mechanic's note — Ray Delgado
Those deep K24 plug tubes collect grit that'll score a cylinder wall if it falls in. I blow them out and vacuum twice before the socket even goes in — cheap insurance on an aluminum head.
5
Install new plugs — gap check and gentle seating
Use NGK or Denso iridium plugs as Honda intended — cheap copper or platinum substitutes wear out fast in the K24A2. Never invent a gap number: check each new plug against the spec on the underhood emissions sticker or in the owner's manual with a wire gauge, and adjust only the ground strap if needed. Follow the plug maker's guidance on anti-seize (most iridium plugs go in dry). Hand-thread every plug several turns until it seats — if it binds, back out and restart — then finish with just the small final tightening the manufacturer specifies, since the aluminum head strips easily.
6
Reassembly — coils, connectors, and cover
Dielectric grease inside each boot, then slide each coil down until it seats over the plug. Reinstall the four 10mm hold-down bolts — snug, not tight. Push each connector until it clicks; tug to verify. Refit the cover, reconnect battery.
🔧 Mechanic's note — Ray Delgado
A misfire right after a plug job is almost never the plugs — it's a coil connector that didn't click home. I give every connector a hard tug before the cover goes back on. Saves pulling everything apart again.
7
Verification — start, idle check, and interval note
Start up — idle glass-smooth, no check-engine light. Test-drive the VTEC range; listen for a miss under load. Iridium plugs are rated 105,000 miles. A post-job misfire code almost always means a coil connector isn’t clicked — recheck those first.
All Done!
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
- • Using cheap non-iridium plugs that wear out in a fraction of the 105,000-mile interval.
- • Not pushing coil connectors on until the tab clicks, then chasing a phantom misfire.
- • Cross-threading a plug by starting it with the ratchet instead of threading it in by hand first.
