On-Vehicle Inspection [11/2021 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT FOR COOLANT LEAK

Remove the reserve tank cap.

Fill the radiator reserve tank assembly with engine coolant, and then install a radiator cap tester.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Radiator Cap Tester

Warm up the engine.
Pump the radiator cap tester to 118 kPa (1.2 kgf/cm² , 17 psi), and then check that the pressure does not drop.
- If the pressure drops, check the hoses, radiator assembly and engine water pump assembly for leaks.
- If there are no signs of external engine coolant leaks, check the heater core, cylinder block sub-assembly and cylinder head sub-assembly.
Remove the radiator cap tester.
Install the reserve tank cap.

INSPECT ENGINE COOLANT LEVEL IN RESERVOIR

Check that the engine coolant level is between the low line and full line when the engine is cold.

If the engine coolant level is low, check for leaks and add engine coolant to the full line.

NOTE:

Do not substitute plain water for engine coolant.

*a	Full Line
*b	Low Line

INSPECT ENGINE COOLANT QUALITY
1. Remove the reserve tank cap.
2. Check that there are no excessive deposits of rust or scale around the reserve tank cap and water filler hole. Also, the engine coolant should be free of oil.
  If excessively dirty, clean the engine coolant passage and replace the engine coolant.
3. Install the reserve tank cap.