2001 Lexus GS 300 User Guide 1 - Page 274

ENGINE If the coolant level drops within a short time after replenishing, there may be a leak in the system. Visually check the radiator, hoses, engine coolant filler cap, radiator cap and drain cock and water pump. If you can find no leak, have your Lexus dealer test the cap pressure and check for leaks in the cooling system. Coolant type selection Use of improper coolants may damage your engine cooling system. Your coolant must contain ethylene-glycol type coolant for a proper corrosion protection of your engine that contains aluminum components. Use "Toyota Long Life Coolant" or equivalent. In addition to preventing freezing and subsequent damage to the engine, this type of coolant will also prevent corrosion. Further supplemental inhibitors or additives are neither needed nor recommended. Read the coolant container for information on freeze protection. Follow the manufacturer's directions for how much to mix with plain water (preferably demineralized water or distilled water). The total capacity of the cooling system is given on page 245 or 247. We recommend to use 50% solution for your Lexus, to provide protection down to about -35_C (-31_F). When it is extremely cold, to provide protection down to about -50_C (-58_F), 60% solution is recommended. Do not use more than 70% solution for better coolant performance. CAUTION To prevent burning yourself, do not remove the radiator cap when the engine is hot. NOTICE Do not use alcohol type antifreeze or plain water alone. 256