Parts for your 2012 Honda Civic-Manifold gasket

2012 Honda Civic manifold gasket — what it does and when to sort it

Yes, a manifold gasket is absolutely used on the 2012 Honda Civic. Honda’s 2012 Civic Service Manual and the Honda Electronic Parts Catalogue list both an intake manifold gasket and an exhaust manifold gasket for the R18 1.8‑litre models, with common OEM references such as 17105‑RNA‑A01 (intake) and 18115‑RNA‑A01 (exhaust). Major gasket catalogues also specify direct-fit parts for this year and engine, confirming the Civic runs them from factory.

On this model, the intake manifold gasket seals the junction between the intake manifold and the cylinder head, keeping unmetered air out so the engine control unit can manage fuelling spot-on. If that seal goes, expect a rough idle, lean codes (like P0171), a hiss under the bonnet, and higher fuel use. The exhaust manifold gasket sits between the head and the exhaust manifold/catalyst assembly. Its job is to keep hot gases in the system so the O2 sensors read correctly and you don’t cop a noisy tick or fumes sneaking into the cabin.

There’s no set replacement interval in the handbook, they’re serviced on condition. As part of regular servicing around 100,000–150,000 kilometres or when chasing drivability issues, it’s smart to inspect for:

• Hissing (intake) or a sharp ticking on cold start (exhaust)
• Soot marks around the exhaust flange, or fuel trims trending lean on a scan tool
• Idle that hunts, misfires, or eggy exhaust smell

If a gasket’s crook, replacement is straightforward for a trained tech. Follow the factory torque sequence and specs, clean the mating faces to bare metal (no gouges), and never over-tighten the hardware. Use an OEM or quality aftermarket multi-layer steel/graphite gasket, avoid smearing RTV unless the manual specifically calls for a dab at a joint. On the intake side, check the throttle body gasket and any manifold O-rings while you’re in there. On the exhaust side, heat-cycled studs and copper nuts are cheap insurance—replace any that look fatigued. After refit, a quick scan of short- and long-term fuel trims plus a listen for leaks will confirm the job’s sweet as.

Done right, a fresh manifold gasket keeps the Civic quiet, efficient, and compliant with emissions—no fumes, no drama, just tidy motoring across Aussie and Kiwi roads.

Popular questions

What are the symptoms of a bad manifold gasket on a 2012 Honda Civic?
Common signs include a hissing noise and rough idle (intake leak), or a ticking sound on cold start and soot around the manifold area (exhaust leak). You might also see a check engine light with lean mixture codes, higher fuel consumption, or a whiff of exhaust in the cabin.

How much does manifold gasket replacement cost in Australia or New Zealand?
Ballpark figures: intake manifold gasket jobs typically land around 1.0–2.0 hours of labour plus the gasket, exhaust manifold gasket can range 1.5–3.0 hours depending on access and seized hardware. Parts are usually modest, total fitted cost often sits in the few hundreds of dollars, varying by shop rates and region.

Is it safe to keep driving with a leaking manifold gasket?
It’s not ideal. An intake leak can run the engine lean and cause poor performance, an exhaust leak can be noisy, skew O2 readings, and potentially let fumes enter the cabin. Short trips to the workshop are generally fine, but it’s best to get it sorted promptly.