How do you get the air lock out of a 2.5 Oldsmobile engine?

The fill cap and neck are supposed to be at the high point of the system to help air bleed out, but often they aren't. And even if they are, you need all the natural help you can get. So jack up the front of the car, which gets the coolant fill neck as high as possible. Check for air bleeds on the engine. Sometimes you'll see an obvious air bleed, such as a boltlike item threaded into a hose. If there's an air bleed, open it. If there are several, open them all. Pour in the required amount of antifreeze slowly until you see coolant oozing out of the open air bleeds. Then close the bleeds and top off the system with the remaining 50/50 mix. If the system has a heater coolant valve, close it by moving the temperature control lever or knob to cold. With the engine running at fast idle and warmed up, have a helper move the lever or knob to hot while you listen at the coolant valve. If after the first rush of coolant you hear a continuous gurgling noise, there's still air in the coolant, and you should be prepared to watch the coolant level in the reservoir over the next few weeks.