2026-10-08 · 5 min read
Subaru WRX STI Head Gasket Malaysia
Head gasket integrity is a known concern on EJ-series engines including the EJ257, particularly on high-mileage, modified, or previously overheated examples. Warning signs include coolant loss without visible leaks, white smoke from the exhaust, milky oil or coolant contamination, and overheating. Prevention is key: maintain fresh coolant, never overheat the engine, and use OEM head bolts with proper torque specification. Repairs typically use Subaru OEM or Cosworth head gaskets with new head bolts.
Subaru WRX STI Head Gasket
- STI EJ257 head gasket: EJ257 is an evolution of EJ25 — same basic architecture; early VA STI (2014–2016) had some reports of head gasket seepage at high mileage; later revisions improved; stock boost EJ257 well-maintained has acceptable longevity
- STI head gasket risk factors: running low-octane fuel (causes knock and detonation — destroys head gasket seal); overheating events (even one overheating episode can damage EJ257 head); high boost tuning above 350 hp without head stud upgrade
- STI head gasket prevention: use RON97; change oil every 5,000 km; never let engine overheat; check coolant level monthly; for tuned STI above 300 hp — install ARP head studs and MLS head gasket proactively
- STI head gasket repair: EJ257 head gasket replacement is major work — engine out or engine-in depending on workshop; always resurface head; replace head studs with ARP; use OEM or Cometic MLS gasket; replace coolant and oil post-repair