1997 Pontiac Firebird Owner's Manual - Page 276

NOTICE: If you use an improper coolant mix, your engine could overheat and be badly damaged. The repair cost wouldn'tbe covered by your warranty. Too much water in the mix can freeze and crack the engine, radiator, heater core and other parts. If you have to add coolant more than four times a year, have your dealer check yourcooling system. Checking Coolant NOTICE: If you use the propercoolant, you don't have to add extrainhibitors or additives which claimto improve the system. These can be harmful. When your engine is cold, check the dipstick on the cap of the coolant recovery tank. The coolant levelshould be at COLD, or a littlehigher. When your engine is warm, the levelon the dipstick should be up to HOT, or a littlehigher. 6-31