2026-10-08 · 5 min read
Subaru WRX STI Timing Belt Replacement Malaysia
IMPORTANT: The WRX STI EJ257 uses a timing BELT, not a chain — this is the most critical scheduled replacement on the car. Replace the timing belt every 100,000 km or 10 years, whichever comes first. When replacing the belt, always replace the water pump, tensioner, and idler pulleys as a complete kit at the same time. A snapped timing belt on the EJ257 will destroy the engine — this is a non-interference-style engine in design but real-world belt failures cause severe damage. Never skip or delay this service.
WRX STI EJ257 Timing Chain
The EJ257 uses timing chains. Unlike the EJ205 which had a belt, the EJ257 chain is robust. However, oil quality is critical — high boost engines create more blowby, which degrades oil faster. Use premium 5W-30 or 0W-40 full synthetic; change by 7,500 km maximum. Cold start oil pressure to the chain tensioners is critical in the boxer layout — do not rev hard on cold start.