Parts for your 2004 Holden Commodore-Head gasket

2004 Holden Commodore head gasket — what it does and when to sort it

A head gasket absolutely is used on the 2004 Holden Commodore. Whether it’s the late VY Series II 3.8‑litre Ecotec V6, the early VZ 3.6‑litre Alloytec V6, or the 5.7‑litre Gen III LS1 V8, each engine runs a cylinder head gasket as specified in the Holden VY/VZ workshop manuals and GM Powertrain service information. Those factory sources describe multi‑layer steel (MLS) head gaskets and torque‑to‑yield head bolts for these engines (see Holden VY Series II Service Manual – Engine Mechanical (V6), Holden VZ Service Manual – Engine Mechanical (Alloytec V6 and Gen III V8), and GM LS1/LY7 service data).

The head gasket’s job is simple but critical: it seals combustion pressure while keeping engine oil and coolant in their own passages between the block and the cylinder head. On the Commodore’s Alloytec and LS1, the OEM MLS gasket handles heat cycling well when the cooling system is healthy. Correct clamping force from new torque‑to‑yield head bolts and the factory torque/angle procedure is essential, as highlighted in the Holden and GM manuals.

It’s not a scheduled service item, so the best “maintenance” is protecting it with proper cooling‑system care. Use the Holden‑specified OAT long‑life coolant (the red stuff for VZ Alloytec and later) and don’t mix types. Keep the radiator clean, replace the cap and thermostat when due, and fix any overheating pronto. Common warning signs include:

• Unexplained coolant loss, white steam from the exhaust, or sweet smell
• Overheating, pressurised hoses when cold, or bubbles in the header tank
• Milky oil on the dipstick or under the oil cap
• Rough cold start, misfire, or low compression on one cylinder

On the older 3.8 Ecotec, intake manifold gaskets often fail before the head gasket, so a proper pressure test and combustion‑gas test in the coolant are worth doing before tearing in. If a head gasket is required, a quality MLS replacement, brand‑new head bolts, a checked/flat cylinder head, meticulous surface cleaning, and adherence to the factory torque‑angle sequence are non‑negotiable. Smart add‑ons during the job include a cooling‑system flush, fresh coolant, and inspections of the water pump, thermostat, and hoses. It’s a labour‑heavy repair, so choosing a workshop familiar with Holden VZ Alloytec or LS‑series procedures (as per the manuals above) will save headaches down the track.

FAQ

Does a 2004 Holden Commodore have a head gasket?
Yes. Every 2004 Commodore engine variant (VY II 3.8 V6, VZ 3.6 Alloytec V6, and LS1 V8) uses a cylinder head gasket, per Holden and GM service manuals. They’re MLS designs clamped with torque‑to‑yield head bolts.

Is it safe to drive with a suspected blown head gasket?
Not really. Even short trips can overheat the engine, warp the head, or hydrolock a cylinder. If you see white steam, rising temps, or milky oil, stop driving and get it inspected.

How much does a head gasket job cost on a 2004 Commodore?
It varies with engine and condition. As a ballpark in AU/NZ, a V6 can land around $1,500–$3,500, and an LS1 V8 can run higher, especially if machining, timing components, or cooling parts are added. A thorough diagnostic first may save you if it’s just an intake gasket or a cooling issue.