2006 Cadillac STS-V Owner's Manual - Page 351

{CAUTION: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine. one-quarter of a turn. If you hear a hiss, wait for that to stop. This will allow any pressure still left to be vented. 2. Then keep turning the pressure cap slowly, and remove it. 3. Add the proper DEX-COOL® coolant mixture to the fill neck, until the coolant reaches the COLD FILL line on the fill neck. 4. With the Intercooler System pressure cap off, start the engine and let it run for a couple of minutes. Then turn the engine off. By this time, the coolant level inside the fill neck may be lower. If the level drops to where coolant is no longer visible in the horizontal tube section of the fill neck, with the engine off add more of the DEX-COOL® coolant mixture to the fill neck until the level is again visible in the horizontal tube section. 5. Then replace the pressure cap. Be sure the pressure cap is hand-tight and fully seated. If the coolant is not at the proper level when the system cools down again, see your dealer. 1. You can remove the Intercooler System pressure cap when the Intercooler System, including the upper intercooler hoses, are no longer hot. Turn the pressure cap slowly counterclockwise about 5-39