Parts for your 2012 Holden Commodore-Exhaust gasket

2012 Holden Commodore exhaust gaskets: what they do and when to replace them

Yes, the 2012 Holden Commodore does use exhaust gaskets. Technical sources including the GM Holden VE Series II Workshop Manual (Engine Exhaust section), GM Global Service Information (SI) procedures for the MY12 V6 (LFX) and V8 (L77), and ACDelco AU/NZ parts catalogues list manifold-to-head gaskets and flange/crush-ring gaskets used between the exhaust manifolds, catalytic converter/front pipes and sections of the system. Those factory procedures also specify replacing these gaskets whenever the joint is disturbed.

An exhaust gasket seals hot gases where the manifold bolts to the cylinder head and where the pipes and cats join. On a 2012 Commodore—whether it’s the Alloytec/SIDI V6 or the 6.0-litre V8—the manifold gasket is a multi-layer steel or composite piece designed to handle heat cycles without crushing out. The flange joints commonly use a metal crush ring or graphite-style gasket to keep the system airtight and quiet while allowing a bit of movement.

Why it matters? A leaking exhaust gasket can sound like a sharp tick on cold start, leave sooty marks around the joint, make the cabin smell fumey and skew O2 sensor readings, which can nudge fuel trims and economy. Left alone, it can erode mating surfaces and in bad cases cook nearby components.

As part of regular servicing, it’s smart to:

• Listen for ticking at cold start and under light load.
• Visually check manifold flanges and pipe joints for black soot or loose hardware.
• Inspect heat shields, studs and springs, LS V8s can occasionally snap manifold bolts after many heat cycles.

Replacement is straightforward for a pro: follow the Holden torque sequence and specs from the workshop manual, clean mating faces, and always fit new gaskets when a joint is opened. Manifold gaskets are not a “retorque” item—once clamped to spec, they’re left alone. Flange crush rings should never be reused. Using a small dab of high-temp anti-seize on fastener threads (not on gasket faces) helps the next service, but keep it off O2 sensors.

There’s no fixed replacement interval—these are replaced on condition. If there’s noise, fumes, or a joint has been apart for other work (cats, headers, or gearbox removal), budget new gaskets. That keeps the Commodore quiet, compliant, and breathing as the factory intended.

Popular questions about 2012 Holden Commodore exhaust gaskets

What are the signs my Commodore’s exhaust gasket is leaking?
Owners usually notice a ticking noise on cold start that softens as the metal warms up. There may be a whiff of exhaust near the engine bay, light soot around a flange, or a faint hiss under load. Scan data can show fuel trims chasing a leak ahead of the O2 sensor.

How often should the exhaust gaskets be replaced?
There’s no time or kilometre interval. Replace them if there’s a leak or whenever an exhaust joint is separated for other work. Always use new flange crush rings and, per GM SI, fit new manifold gaskets when manifolds come off.

Is it safe to drive with a leaking exhaust gasket?
Short trips might be possible, but it’s not recommended. Exhaust gases can enter the cabin, noise increases, and the engine management may compensate for false O2 readings. Fix it promptly to avoid warped flanges or seized hardware down the track.