Parts for your 2000 Holden Commodore-Manifold gasket

2000 Holden Commodore manifold gasket: what it does and when to replace it

Based on Holden VT/VX Series workshop manuals, GM Powertrain service information for the 3.8‑litre V6 (Ecotec/3800 Series II) and 5.7‑litre Gen III V8 (LS1), plus OEM parts catalogues from Holden/ACDelco and Fel‑Pro application guides, the 2000 Holden Commodore absolutely uses manifold gaskets. Both the intake and exhaust manifolds rely on dedicated gasket seals between the manifold and the cylinder heads, and the V6 also uses gaskets between the upper plenum and lower intake. So “manifold‑gasket” is directly relevant to this model year.

On this Commodore, the manifold gaskets keep the engine airtight (intake side) and gas‑tight (exhaust side). Intake manifold gaskets prevent vacuum leaks and, on the V6, keep coolant passages sealed within the lower intake. Exhaust manifold gaskets help stop hot exhaust blow‑by, reduce noise, and protect nearby components. When these seals age, flatten, or harden, they can cause rough idle, lean running, ticking noises, coolant seepage (V6), and that unmistakable exhaust leak smell.

They’re not a routine “replace every X kilometres” item, they’re replaced on condition. Still, during regular servicing it pays to check for tell‑tales: fuel trims creeping positive, a faint high‑pitched tick from cold that quietens warm, coolant disappearing with no obvious drip (V6 lower intake), or sooty marks around an exhaust port. Catching a lazy gasket early can save a bigger job later.

If replacement’s on the cards, follow the workshop torque specs and sequence religiously—both engines are sensitive to uneven clamping. Use quality gaskets designed for the exact engine code. On the V6 lower intake, apply the specified RTV at the china wall junctions only, not across ports. Clean and inspect mating faces, chase bolt threads, and replace any distorted or pitted hardware. After reassembly, perform a smoke test (intake) or a quick cold‑start listen test (exhaust) to confirm the seal. It’s also smart to renew related consumables while you’re there—throttle body gasket, injector O‑rings, and any brittle vacuum hoses.

• Common symptoms to watch: rough idle, hiss or whistle under the bonnet, coolant smell or milkiness (V6), exhaust tick, and higher fuel use.
• Best practice: use OEM‑equivalent gaskets, keep surfaces spotless, and recheck fasteners after a few heat cycles if the manual calls for it.

FAQs

Does a 2000 Holden Commodore actually have a manifold gasket?
Yes. Factory service manuals for VT/VX and GM Powertrain documentation list intake and exhaust manifold gaskets for both the 3.8‑litre V6 and 5.7‑litre V8. The V6 also has an upper plenum gasket and a lower intake gasket that seals coolant passages.

What are the signs my Commodore’s manifold gasket is failing?
Look for rough idle, a check engine light with lean codes, a hissing noise, or coolant loss without obvious leaks on the V6. For exhaust leaks, a ticking sound on cold start that quietens as it warms is classic, along with a sooty mark near the manifold flange.

How hard is it to replace the intake manifold gasket?
On the LS1 V8 it’s a straightforward remove‑and‑refit of the intake with new port gaskets. On the V6, a lower intake job is more involved due to coolant sealing and torque sequencing. A competent DIYer with a torque wrench can do it over a day, workshops typically allow several hours plus parts and coolant.