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2.5 Boxer petrol (EJ25)

2008–2011 · petrol · 2457cc · 172hp

Engine codes: EJ25

History-Dependent

Reliability, common problems and owner reviews for the Subaru Impreza / Forester 2.5 Boxer petrol (EJ25). Check this before you buy used.

The naturally-aspirated EJ25 is the engine behind Subaru's head-gasket reputation: external oil/coolant leaks from the head gaskets typically appear around 90,000–150,000 miles on pre-2011 units. Subaru redesigned the gasket for 2012, dramatically cutting failures. A car with gaskets already done (or a 2012+ design) is fine; an original pre-2011 one is on borrowed time.

Same engine, other cars

This is the same physical engine (EJ25) sold under different names across brands. Reliability is broadly shared — cross-check these:

Known Issues

Head gasket failurecritical

EJ25 head gaskets leak (usually externally, oil/coolant) around 90,000–150,000 miles on pre-2011 engines. Redesigned gasket from 2012.

Fix / Workaround: Check for oil/coolant weeping at the heads; ask if gaskets were replaced (with updated parts); prefer 2012+.

Repair cost: €800–€2000

Typically appears after: 145,000 km

Coolant maintenance dependencyrecurring

Old/acidic coolant accelerates gasket failure.

Fix / Workaround: Fresh coolant every 2–3 years; regular oil changes.

Repair cost: €50–€150

Year Cutoffs

2012: Before — Pre-2011 EJ25 — head-gasket failure prone. After — 2012 redesigned gasket — failures dramatically reduced.

Mileage Thresholds

After 145,000 km: Head-gasket failure window (~90k–150k miles).

Pre-Purchase Checklist

  • ☐Inspect heads for oil/coolant weeping
  • ☐Ask if head gaskets were done (updated parts)
  • ☐Prefer 2012+ design
  • ☐Check coolant condition/history

Frequently asked questions

Is the Subaru Impreza / Forester 2.5 Boxer petrol (EJ25) reliable?

History-Dependent — The naturally-aspirated EJ25 is the engine behind Subaru's head-gasket reputation: external oil/coolant leaks from the head gaskets typically appear around 90,000–150,000 miles on pre-2011 units. Subaru redesigned the gasket for 2012, dramatically cutting failures. A car with gaskets already done (or a 2012+ design) is fine; an original pre-2011 one is on borrowed time.

What are the common problems and reviews for the Subaru Impreza / Forester 2.5 Boxer petrol (EJ25)?

The most commonly reported problems: Head gasket failure, Coolant maintenance dependency.

Is a used Subaru Impreza / Forester 2.5 Boxer petrol (EJ25) worth buying?

The engine itself is OK; condition is everything. Unknown or patchy history = walk away.