On-Vehicle Inspection

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT COOLING SYSTEM FOR LEAKS
1. Remove the water outlet cap.
  CAUTION: To avoid the danger of being burned, do not remove the water outlet cap while the engine and radiator are still hot. Thermal expansion will cause hot engine coolant and steam to blow out from the radiator.
2. Fill the radiator with coolant, then attach a radiator cap tester.
  
  Fig 1: Attaching Radiator Cap Tester
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Warm up the engine.
4. Pump it to 118 kPa (1.2 kgf/cm² , 17.1 psi), then check that the pressure does not drop.
  If the pressure drops, check the hoses, radiator and water pump for leaks. If there are no signs or traces of external coolant leaks, check the heater core, cylinder block and head.
5. Reinstall the water outlet cap.
CHECK ENGINE COOLANT LEVEL AT RESERVOIR
1. The engine coolant should be between the "LOW" and "FULL" lines when the engine is cold. If low, check for leaks and add "Toyota Super Long Life Coolant" or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid technology up to the "FULL" line.
CHECK ENGINE COOLANT QUALITY
1. Remove the water outlet cap.
  CAUTION: To avoid the danger of being burned, do not remove the water outlet cap while the engine and radiator are still hot. Thermal expansion will cause hot engine coolant and steam to blow out from the radiator.
2. Check if there are any excessive deposits of rust or scale around the water outlet cap and water outlet filler hole; the coolant should free of oil.
  If excessively dirty, replace the coolant.
3. Reinstall the water outlet cap.
INSPECT FIN BLOCKAGE
1. If the fins are clogged, wash them with water or a steam cleaner, then dry with compressed air.
  
  Fig 2: Drying Fins With Compressed Air
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  NOTE:
  - If the distance between the steam cleaner and core is too close, there is a possibility of damaging the fins, so keep the following injection distance.
    
    Fig 3: Injection Pressure & Distance Specifications Chart
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  - If the fins are bent, straighten them with a screwdriver or pliers.
  - Be careful not to expose electronic components to water.