Parts for your 2003 Holden Commodore-Manifold gasket

2003 Holden Commodore manifold-gasket — what it does and when to sort it

Based on the Holden VY Series Workshop Manual (GMH), Ellery’s Holden Commodore VT–VZ Service & Repair Manual, and parts catalogues from AC Delco and Fel‑Pro, the 2003 Holden Commodore is absolutely fitted with manifold-gaskets. Both the 3.8‑litre Ecotec V6 (including supercharged variants) and the Gen III 5.7‑litre LS1 V8 use intake and exhaust manifold-gaskets, making the manifold-gasket relevant for this model year.

The manifold-gasket’s main job is sealing. On the intake side it keeps the engine airtight so it can pull the right amount of air and fuel without vacuum leaks, and on some engines it also keeps engine coolant confined where it crosses the intake. On the exhaust side it seals hot gases so they don’t leak out before the catalytic converter, keeping things quiet and compliant. If a manifold-gasket fails, you can cop rough idle, higher fuel use, a check engine light, coolant loss (on V6 intake), or an annoying exhaust tick (often on LS1 V8s). Holden’s own service information and common workshop practice note that VY V6 intake manifold-gaskets can age and seep coolant externally or into the valley—so staying on top of it is smart.

• Typical clues: sweet coolant smell or dampness around the intake joins (V6), milky oil, hard cold starts, lean codes, whistle/rough idle, or an exhaust tick under load.
• Prevention helps: fresh long‑life coolant (Holden red) at correct intervals, proper system pressure, and fixing vacuum line cracks early.

Replacement isn’t a scheduled service item, it’s done when symptoms show. On a VY V6, many techs choose updated manifold-gasket sets with an alloy carrier for better longevity. The job involves carefully cleaning mating faces, following the factory torque sequence in stages, and using the correct sealant only where specified. After an intake manifold-gasket on the V6, it’s wise to change the oil and filter if there’s any hint of coolant contamination, bleed the cooling system properly, and recheck fluid levels over the next few drives.

For exhaust manifold-gaskets (common on LS1s with a tick), inspect studs and flanges, replace any warped or cracked bits, and torque to spec. None of these gaskets are a “nip‑up later” item—once torqued correctly they usually don’t need re‑tightening. DIYers should have the VY manual handy, for most owners, a reputable workshop is the go. As a ballpark, intake manifold-gasket labour on a V6 is several hours, exhaust manifold-gasket on a V8 can be quicker unless studs fight you. Quality parts and patience under the bonnet go a long way.

Popular questions

Does a 2003 Holden Commodore actually have a manifold-gasket?
Yes. Technical references including the Holden VY Series Workshop Manual, Ellery’s VT–VZ manual, and AC Delco/Fel‑Pro catalogues list intake and exhaust manifold-gaskets for both the Ecotec V6 and LS1 V8. So the manifold-gasket is definitely used on this model.

What are the common signs the manifold-gasket is on the way out?
On the V6, look for coolant seepage around the intake manifold edges, a sweet smell, rising temperature, or milky oil. Vacuum leaks can cause rough idle or lean fault codes. On the LS1 V8, a sharp tick on cold start that quietens when hot can point to an exhaust manifold-gasket leak.

How much does replacement usually cost in Australia or NZ?
Parts vary from budget to OE‑quality: roughly AUD/NZD $80–$250 for a full intake set on the V6, and less for exhaust manifold-gaskets. Labour can be 3–6 hours for a V6 intake job and 1–3 hours per side for an LS1 exhaust gasket, depending on access and stubborn studs. A shop can quote more accurately after inspection.