2026-10-08 · 5 min read
Subaru WRX STI Oil Leak Repair Malaysia
Oil leaks are a well-known characteristic of high-mileage EJ-series engines. The most common leak points on the EJ257 are the cam seals (front and rear on both camshafts), the front crankshaft seal, the rear main seal, and the rocker cover gaskets. These typically appear after 100,000 km. All are serviceable — early attention prevents oil contamination of accessory belts and clutch components.
Subaru WRX STI Oil Leak
- STI EJ257 oil leak points: rocker cover gaskets (4 covers — very common on older STI above 100,000 km), front crankshaft seal, rear crankshaft seal, and oil separator (PCV related)
- STI rocker gasket: EJ257 rocker cover gaskets are known failure item — harden and crack from EJ257 heat cycles; small leak drips onto hot exhaust; replace all 4 covers at 100,000 km service for peace of mind
- STI turbo oil: STI IHI turbo has oil feed and return; older STI with worn turbo shows blue smoke at start — turbo shaft seals worn; do not delay — if turbo has oil leak into intake, clean intercooler to prevent hydro-lock risk
- STI oil separator: EJ257 oil separator on PCV system captures crankcase vapour; if separator fails, oil deposits appear in intake manifold and throttle body; inspect oil separator at 80,000 km — cheap prevention compared to intake cleaning