Parts for your 2011 Subaru Impreza-Manifold gasket

2011 Subaru Impreza manifold gasket: what it does and when to replace it

Yes, a manifold gasket is absolutely fitted to the 2011 Subaru Impreza. Technical references including the Subaru Factory Service Manual for the GE/GH/GR/GV series and the Subaru Genuine Parts catalogue show both intake manifold gaskets (between the intake runners and cylinder heads) and exhaust manifold gaskets (between the headers and heads). Major aftermarket catalogues for the EJ20/EJ25 engines used in 2011 Imprezas also list these gaskets, confirming they’re standard service parts rather than optional extras.

On this model, the manifold gaskets do the quiet but crucial work of sealing high‑vacuum intake paths and hot exhaust streams so the engine can meter air and fuel accurately, maintain torque, and keep noise and emissions in check. Intake manifold gaskets stop unmetered air sneaking in, which would skew fuel trims and make the car run lean. Exhaust manifold gaskets prevent blow‑by that can cause a cold‑start tick, hot gas leaks near the heads, and O2 sensor confusion. WRX and other turbo variants also use additional gaskets on the up‑pipe, turbo and downpipe flanges.

They’re not a scheduled replacement item, but they’re considered “replace on removal” parts. Good moments to do them are whenever the manifold is off for other work (injectors, tumble‑valve service, timing belt access) or if symptoms appear, such as:

• Hissing or whistling at idle, surging idle, lean codes (e.g., P0171), or rough cold starts
• Exhaust tick when cold, soot traces around the flange, exhaust smell in the bay, or a slight loss of low‑down torque

For servicing, use quality OEM‑equivalent multi‑layer steel or graphite gaskets. Fit them clean and dry unless the Subaru manual explicitly specifies a sealant (it generally doesn’t for intake or exhaust manifold gaskets). Clean mating faces carefully, check for warped flanges, and torque fasteners in the recommended sequence and stages. On older EJ engines, seized studs or nuts are common, so a heat cycle and penetrant beforehand can save drama. After any intake work, it’s smart to smoke‑test for vacuum leaks and verify fuel trims with a scan tool.

There’s no strict kilometre interval, but many workshops in Australia and New Zealand will inspect or proactively replace the intake gaskets around 100,000–150,000 km if the manifold is coming off anyway, and renew exhaust gaskets whenever the headers are disturbed. It’s simple insurance for smooth running, proper emissions, and a quieter cabin.

Do all 2011 Subaru Imprezas (including WRX) use manifold gaskets?

They do. All engines in the 2011 range use intake and exhaust manifold gaskets. Turbo versions add extra sealing rings at the up‑pipe, turbo, and downpipe joints. If a manifold is removed, new gaskets should be installed.

How much does manifold gasket replacement cost in AU/NZ?

Parts typically range from about AUD/NZD $25–$80 for an intake gasket set and $30–$120 for exhaust gaskets. Labour varies with model: intake 1.5–3.5 hours, exhaust 1–2 hours