3. The coolant is the first fluid that needs to be drained from the vehicle when removing the engine. If the engine is going to be torn down once removed, now is also a good time to drain the oil. To drain the coolant, open the petcock at the bottom of the radiator on the passenger side of the vehicle (indicated by the finger in the picture). As a note, the Gen III V-8 uses a 50/50 mix of Dexcool and water.