On-Vehicle Inspection [08/2020 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus ES 250, 2023 Lexus ES 250, 2022 Lexus ES 250, and 2021 Lexus ES 250. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT FOR COOLANT LEAK

WARNING:

Do not remove the radiator cap sub-assembly while the engine and radiator assembly are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.

Remove the radiator cap sub-assembly.

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

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*a	Radiator Cap Tester

Warm up the engine.
Pump the radiator cap tester to 103 kPa (1.1 kgf/cm² , 15 psi), and then check that the pressure does not drop.
- If the pressure drops, check the hoses, radiator assembly and engine water pump assembly (water inlet housing) 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 radiator cap sub-assembly.

INSPECT ENGINE COOLANT LEVEL IN RESERVOIR TANK

Check that the engine coolant level is between the L line and F line when the engine is cold.

*a	F Line
*b	L Line

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

NOTE:

Do not substitute plain water for engine coolant.

INSPECT ENGINE COOLANT QUALITY
WARNING:
Do not remove the radiator cap sub-assembly while the engine and radiator assembly are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.
1. Remove the radiator cap sub-assembly.
2. Check if there are any excessive deposits of rust or scale around the radiator cap sub-assembly and water filler hole. Also, the engine coolant should be free of oil.
  If excessively dirty, replace the engine coolant.
3. Install the radiator cap sub-assembly.