Parts for your 2017 Holden Commodore-Oil cap

2017 Holden Commodore Oil Cap — Purpose, Care and When to Replace

Technical sources confirm the 2017 Holden Commodore absolutely uses an engine oil filler cap. The Holden VF Series II Owner’s Manual (2017) identifies the oil filler cap under the bonnet as part of the engine compartment layout, and GM Global Service Information (GMSi) includes an oil filler cap and seal inspection within the lubrication system procedures for the VF/VF II V6 and LS3 V8 engines. So yes, an oil-cap is fitted and relevant on this vehicle.

On a 2017 Holden Commodore, the oil-cap’s job is simple but critical: it seals the top of the engine’s oil filler neck to keep dust, moisture and grit out, while helping the crankcase ventilation system maintain the right pressure. Pop the bonnet and it’s typically found on the rocker cover, clearly marked for engine oil. Whether it’s a V6 or the LS3 V8, the cap prevents oil splash, keeps the oil clean for longer, and stops nasty leaks that can make a mess or burn off on hot components.

As part of regular servicing of a 2017 Holden Commodore oil-cap, a quick check goes a long way. Look over the cap for cracks, heat hardening, or a perished O-ring. If the cap doesn’t snug down smoothly or you can smell oil fumes under the bonnet, it could be time for a replacement. GM service literature calls out inspecting the cap and its seal because even a small sealing issue can lead to weeping oil, dust ingress or rough running from unmetered air sneaking into the crankcase system.

• Wipe the cap and filler neck clean at every oil change.
• Inspect the O-ring for flattening or splits, replace the seal or the cap if in doubt.
• If the cap cross-threads or won’t seat, don’t force it—replace it to avoid leaks.
• Use a genuine or quality equivalent cap that matches the engine family to ensure proper fit and venting.

Owners who keep the oil-cap tidy and sealing properly help their Commodore’s oil stay cleaner, reduce smells and stains, and avoid avoidable faults tied to crankcase pressure or contamination. It’s a cheap, quick win during any service.

Where is the oil cap on a 2017 Holden Commodore?

Under the bonnet on the top of the engine, mounted in the rocker/engine cover. On V6 models it’s typically central or slightly offset, and on the LS3 V8 it’s on the rocker cover and clearly marked for engine oil. The Owner’s Manual engine bay diagram points it out for quick identification.

How often should the oil-cap or its O-ring be replaced?

There’s no fixed kilometre interval. Inspect it at every oil change, replace the O-ring or cap if the seal is flattened, brittle, cracked or if there’s visible oil misting. Many cars go years on the original cap, but heat cycles can age the seal.

Are oil caps interchangeable across all VF II engines?

Not reliably. While some GM caps share threads and seals, variations exist between the V6 and LS3 V8 covers. For best results, match the cap to the specific engine code and build—use a genuine Holden/GM or quality aftermarket part specified for the 2017 VF II.