Parts for your 2017 Holden Commodore-Ignition leads

2017 Holden Commodore ignition leads: do you have them, what they do, and when to replace

Short answer: ignition leads are relevant on some 2017 Holden Commodore models, but not all. According to Holden/GM service information for VF Series II (MY2017), the V6 engines (3.0L and 3.6L SIDI, e.g., Evoke, SV6, Calais V6) use a direct, coil-on-plug ignition system with no high-tension leads. The 6.2L LS3 V8 (e.g., SS, SS-V, Redline) uses coil-near-plug ignition with short spark plug leads between each coil and plug. That’s why you’ll see (and service) ignition leads only on the V8 LS3 cars, not on the V6s.

Technical sources referenced: Holden VF Series II Service/Workshop Manual (Engine – Ignition System), GM Service Information (SI) for VF II Commodore powertrains, and GM/ACDelco parts catalogues noting LS3 V8 spark plug wire sets. These documents describe the V6 direct coil-on-plug layout (no leads) and the LS3’s individual coils with secondary leads.

If you’re in an LS3-powered 2017 Commodore, the ignition leads are the flexible, insulated high-tension wires linking each coil to its spark plug. Their job is to deliver a strong, clean spark at precisely the right moment so the LS3 fires smoothly, pulls hard, and keeps fuel use and emissions in check. Because they live under the bonnet, next to hot rocker covers and exhausts, they cop plenty of heat and vibration. Over time, the insulation can harden or crack, the terminals can corrode, and resistance can creep up—leading to misfires under load, rough idle, sluggish acceleration, and higher fuel use.

As part of routine servicing on an LS3 Commodore, it’s a smart move to inspect the ignition leads whenever plugs are checked (often around 100,000–160,000 km, depending on plug type and service schedule). Look for heat damage, oil contamination, splits, or loose boots. If you’ve got a multimeter, check resistance per lead against spec, high or inconsistent readings are a cue to replace. When fitting new leads, replace the full set, route them exactly as per factory clips and heat shields, push boots on until they “click”, and use a dab of dielectric grease in the boots to ease future removal and help seal out moisture. Sticking with quality, heat-rated LS3-specific leads avoids crossfire and radio interference, especially on cars with headers or spirited driving. If you’re chasing a misfire that only shows up on hills or with the A/C on, don’t overlook the leads—they’re a common culprit and an easy win for smoother running.

• V6 (3.0/3.6 SIDI): no ignition leads – coil-on-plug.
• V8 (6.2 LS3): yes – eight short ignition leads, one per cylinder.

FAQs

Does my 2017 Commodore have ignition leads?
If it’s an LS3 V8 (SS, SS-V, Redline), yes—each coil connects to its spark plug with a short lead. If it’s a V6 (Evoke, SV6, Calais V6), no—those engines run coil-on-plug, so there are no traditional high-tension leads to service.

How often should LS3 ignition leads be replaced?
There’s no strict time-based interval, but checking them whenever you service or replace spark plugs is wise. Many owners replace the set around 100,000–160,000 km or earlier if there are misfires, visible heat damage, cracking, or high resistance readings. Performance use or aftermarket headers can shorten their life.

What are the signs my LS3 ignition leads need attention?
Tell-tales include a stumble under load, rough idle, increased fuel use, a ticking sound from arcing, or visible cracks and baked boots. If a scan tool shows cylinder-specific misfires that move when you swap leads between cylinders, that’s a strong hint the lead is the issue.