Parts for your 2015 Subaru Xv-Head gasket

2015 Subaru XV head gasket — what it is and when to sort it

Based on Subaru’s technical literature, a head gasket is absolutely used on the 2015 Subaru XV. The 2.0‑litre FB20 boxer engine has two cylinder heads and therefore two multi‑layer steel (MLS) head gaskets—one per bank. This is documented in the 2015 MY XV/Impreza Service Manual (FB engine section), the Subaru Electronic Parts Catalogue (EPC), and procedures published via Subaru’s Technical Information System (STIS), all of which detail cylinder head gasket specifications and installation steps.

On this XV, the head gasket seals combustion pressure while keeping engine oil and coolant in their proper passages. Because the engine is a flat‑four, the gaskets work horizontally on each bank, coping with heat cycles and pressure every time the driver heads off down the motorway or across town. The FB‑series MLS design is more robust than the older EJ designs, but like any gasket, it relies on correct cooling, clean fluids, and flat sealing faces.

Good servicing habits go a long way. Regular coolant changes with the correct Subaru long‑life coolant, keeping the radiator and cap healthy, and fixing any small overheating issue straight away all help prevent gasket stress. At routine services, a workshop should look for external weeping at the head‑to‑block joint, check for hydrocarbons in the coolant if there are symptoms, and confirm there’s no oil–coolant cross‑contamination.

Tell‑tales that warrant a closer look include:

• Unexplained coolant loss, overheating, or poor cabin heat
• Persistent bubbles in the expansion tank once warm
• Milky sludge under the oil filler cap or sweet‑smelling white exhaust
• Oil or coolant seeping at the head/block seam

If replacement is needed, it’s a significant job. Many techs prefer removing the engine for access on Subaru boxers. Best practice is to use genuine or OE‑quality MLS gaskets, check head and block flatness and surface finish, clean threads, follow the exact torque/angle sequence, and refresh related bits: head bolts (if out of spec), intake/exhaust gaskets, thermostat, radiator cap, and often the water pump. The FB20 uses a timing chain, so there’s no belt to schedule, but it’s sensible to inspect chain guides and front seals while there.

After reassembly, the coolant system must be properly bled (air pockets can mimic gasket issues), and the vehicle road‑tested to operating temperature. With quality parts and careful workmanship, a fresh set of gaskets should deliver many more trouble‑free kilometres for a 2015 XV across Australia or New Zealand.

Popular questions

Do 2015 Subaru XVs still have head gasket problems like older Subarus?
The FB20 engine’s MLS gaskets are generally more durable than the older EJ‑series. Failures are far less common, but they can still occur—usually after overheating, poor coolant maintenance, or very high kilometres. Keeping the cooling system in top nick is the best prevention.

What are the common signs of a failing head gasket on a 2015 XV?
Watch for unexplained coolant loss, overheating, bubbles in the expansion tank, sweet‑smelling white exhaust, rough cold starts, or oil/coolant mixing. External weeping at the head joint is less common on FB engines but still worth checking.

How much does a head gasket job cost and how long does it take?
Costs vary by workshop and what’s replaced at the same time, but as a ballpark in AU/NZ, expect several thousand dollars for parts and labour, with around 10–16 labour hours typical. A precise quote depends on machining needs and whether extras like the water pump and seals are done.