Parts for your 2013 Subaru Outback-Exhaust gasket

2013 Subaru Outback exhaust gasket — what it is and when to sort it

Yes, the 2013 Subaru Outback does use exhaust gaskets. Subaru’s Factory Service Manual for the BR/BM Outback (MY2010–2014) and the Subaru Genuine Parts Catalogue both list exhaust manifold gaskets and pipe-to-pipe “ring/donut” gaskets as required service parts, with the service manual specifying gasket replacement whenever those joints are disturbed. Aftermarket catalogues for this model (2.5i FB25 and 3.6R EZ36) also specify manifold and exhaust pipe gaskets, confirming fitment.

On the 2013 Outback, exhaust gaskets do the quiet but crucial job of sealing hot gases as they leave the engine and travel through the headers, catalytic converters, centre pipe and mufflers. There are typically two types on this model: multi-layer steel (MLS) manifold gaskets that seal the cylinder head to the exhaust manifold, and compressible steel/graphite “donut” or ring gaskets that seal the spring-bolt slip joints between pipes. Together they prevent leaks that can cause ticking noises on cold start, fumes in the cabin, sooty marks around flanges, and dodgy oxygen sensor readings that can upset fuel trim and economy.

They’re not a scheduled replacement item, but they should be replaced any time a joint is undone — for work on the cat, centre pipe, or mufflers, or when chasing leaks. Fresh gaskets are cheap insurance against rework. For Aussie and Kiwi Outbacks that see plenty of corrugations, towing, or coastal exposure, those spring-bolt joints cop extra movement and corrosion, so keeping an eye on them pays off.

Good practice on this Subaru includes cleaning the mating faces, using new spring bolts and nuts where specified, and torquing fasteners to the Subaru service manual spec. Avoid exhaust paste near oxygen sensors, and don’t slap anti-seize on manifold studs unless the procedure calls for it. After fitting, let the system heat-cycle, then recheck for any faint puffs or ticking — a gloved hand near (not on) the joint or a strip of tissue can help spot a tiny leak. If there’s a persistent rasp from the front of the car, look first at the manifold gaskets, if the noise is mid-car and changes with bumps, the donut gasket or a perished hanger is a usual suspect.

When replacing, stick with OEM or a quality brand that matches the original gasket style. A well-fitted gasket keeps the Outback quiet, keeps fumes out of the cabin, and helps the engine management do its job — exactly what’s wanted on a long Trans-Tasman roadie.

• Typical leak signs: ticking on cold start, exhaust smell, sooty streaks at joints, louder note under load.
• Replace gaskets whenever a joint is separated, inspect hangers and heat shields while you’re there.
• Support the exhaust to avoid stressing fresh gaskets, torque to spec from the Subaru service manual.

Popular questions

How can someone tell which exhaust gasket is leaking on a 2013 Subaru Outback?
Cold-start ticking near the engine usually points to a manifold gasket. A rasp or chuff from under the front seats often means a failed donut gasket at the spring-bolt joint. Look for black soot at flanges, feel for puffs (carefully) around joints, and listen for changes as the system warms up. A smoke machine or soapy water on a cool system can help pinpoint tiny leaks.

Do exhaust gaskets need replacing when fitting a new muffler or catalytic converter?
Yes — on this model, any time you undo a flanged or spring-bolt joint, plan on new gaskets. Reusing crushed or heat-cycled gaskets risks immediate leaks. It’s smart to have fresh spring bolts/nuts and hangers on hand too, especially on high-kilometre or coastal vehicles.

Is a donut gasket the same as a flat flange gasket on the Outback?
No. The donut is a tapered ring that seals a ball-and-socket style spring-bolt joint and allows movement as the exhaust expands and the engine rocks. A flat flange gasket is a thin MLS or composite piece used on rigid, bolted flanges like the manifold-to-head. Using the wrong type won’t seal properly.