2026-09-15
Lexus IS 250/300h/350 Water Pump Replacement Malaysia
The IS 250/350 water pump is belt-driven and typically lasts 100,000–150,000 km. Replace when coolant leaks are detected at the pump weep hole or when the impeller bearing becomes noisy. Replacement costs (parts + labour), ideally combined with a coolant flush. The IS 300h uses an additional electric water pump for the hybrid inverter cooling circuit.
Lexus IS Water Pump
- All IS engines use timing chain (not belt) — water pump is driven by the serpentine belt, not the timing chain; separate replacement
- Water pump replacement interval: inspect at 100,000 km; replace if weeping from shaft seal or if bearing has any play
- Signs of water pump failure: coolant drip from front of engine, overheating, squealing noise from belt area — replace pump promptly if any appear
- Water pump + serpentine belt: replace both at the same time — labour overlaps; cost-effective to do together