1996 Lexus GS 300 Owners Manual - Page 187

ENGINE CHECKING THE ENGINE COOLANT LEVEL If the coolant level drops within a short time after replenishing, there may be a leak in the system. Visually check the radiator, hoses, radiator cap, 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. ! CAUTION To prevent burning yourself, do not remove the radiator cap when the engine is hot. Engine coolant selection Park the vehicle at a level spot and look at the see-through coolant reservoir when the engine is cool. The coolant level is satisfactory if it is between the upper and lower lines on the tank. If the level is low, add ethylene-glycol type coolant. The coolant level in the reservoir will vary with the engine coolant temperature. However, if the level is on or below the lower line, add coolant to bring the level up to the upper line. Use only ethylene-glycol type coolant. It will prevent freezing and corrosion. Neither supplemental inhibitors nor additives are needed nor recommended. (For information on ethylene-glycol coolant, see also "Engine coolant selection" described below.) Your coolant must contain ethylene-glycol antifreeze. In addition to preventing freezing and subsequent damage to the engine, this will also prevent corrosion. Further supplemental inhibitors or additives are neither needed nor recommended. Read the antifreeze container for information on freeze protection. Follow the manufacturer's directions for how much to mix with water. The total capacity of the cooling system is given on page 167. We recommend 50% solution be used for your Lexus, or a sufficient quantity to provide protection to about -35°C (-31°F). NOTICE Do not use alcohol type antifreeze or plain water alone. 173