1998 Oldsmobile 88 Owner's Manual - Page 214

6. Start the engine andlet itrun until you can feel the upper radiatorhose getting hot. Watch out the for engine cooling fans. 7. By this time, the coolant level inside the radiator filler neck may be lower. the level is lower, add If more of the proper DEX-COOL@ coolant mixture through the filler neck untilthe level reachesthe base of the filler neck. 8. Then replace the pressure cap. At any time during this procedureif coolant begins to flow out the of filler neck, reinstallthe pressure cap. Be sure the arrows on the pressure cap up like this. line 5-21