Parts for your 2020 Subaru Impreza-Head gasket

2020 Subaru Impreza Head Gasket: What It Does and When to Replace It

Yes, the 2020 Subaru Impreza uses a head gasket. Technical sources that identify this include the Subaru Factory Service Manual for the 2020MY Impreza (FB20D engine), which details a multi‑layer steel (MLS) cylinder head gasket and torque‑to‑yield head bolts in the Engine Mechanical section, the Subaru Genuine Parts Catalogue for the GT-series Impreza, which lists the head gasket by part number for the FB20D, and Subaru technical information resources that outline bolt torque sequences and cooling system procedures. So, a head gasket is absolutely relevant to this model.

On the 2.0‑litre FB20D boxer engine, the head gasket seals the joint between each aluminium cylinder head and the engine block. Its job is threefold: maintain combustion pressure for proper power and efficiency, keep coolant and engine oil in their separate galleries without cross‑contamination, and cope with heat cycles and expansion. The MLS design Subaru specifies offers excellent durability and sealing stability when the cooling system is kept in good nick.

While a head gasket isn’t a scheduled service item, looking after the cooling system is key to long life. For the 2020 Impreza, that means using the correct genuine long‑life coolant, replacing it at the intervals in the maintenance schedule, pressure‑testing the system under the bonnet if there’s any hint of a leak, and ensuring the radiator cap, thermostat, and fans are operating properly. Avoiding overheating is the single best way to protect the gasket. During routine services, a mechanic should check for coolant loss, discoloured oil, and any sweet odour or steam from the exhaust after warm‑up.

If replacement is needed, it’s a precise job that should be done by an authorised workshop. Best practice on the FB20D includes using genuine MLS gaskets, replacing the torque‑to‑yield head bolts, following the Subaru torque‑angle sequence, and checking the cylinder head and block for flatness. It’s also smart to inspect the water pump, timing components, and hoses while access is open. A careful bleed of the cooling system afterwards helps prevent hot spots and future dramas.

• Warning signs can include unexplained coolant loss, bubbles in the overflow bottle, persistent overheating, milky residue on the oil cap or dipstick, and white exhaust vapour after warm‑up.
• Catch issues early and the repair is usually more straightforward and cost‑effective.

FAQs

Do 2020 Subaru Imprezas still have head gasket issues like older models?
The FB‑series engines, including the 2020 Impreza’s FB20D, use robust MLS gaskets and generally have a better track record than the older EJ engines. Failures are uncommon when the cooling system is maintained and the car isn’t overheated. Keeping coolant fresh and fixing leaks early goes a long way.

What are the common signs of a failing head gasket on a 2020 Impreza?
Look for coolant loss with no obvious drips, overheating under load, a sweet smell from the exhaust, white vapour after warm‑up, or milky oil. A workshop can confirm with a cooling system pressure test or a chemical test for combustion gases in the coolant.

How long does head gasket replacement take, and what else should be done?
Workshop time varies with inspection findings, but plan on several days including machining checks and parts ordering. It’s sensible to renew head bolts, coolant, and any tired hoses, and to inspect the water pump and timing components while access is open for peace of mind.