The engine coolant in a Nissan 300ZX ensures that the engine operates normally without overheating. The coolant flows through a series of hoses and a radiator to draw heat away from the engine and internal components. Engine coolant that circulates through the 300ZX is actually comprised of a mix of 50% anti-freeze solution and 50% water. Over time, the coolant will pick up contaminates while flowing through the system, the water will slowly evaporate from the system, or the anti-freeze solution will begin to break down. Eventually, you'll need to know how to change the engine coolant in a Nissan 300ZX so you can keep your engine running properly.
If you've just driven the vehicle, wait several hours for the engine to cool down completely. Apply the parking brake.
Open the radiator cap.
Place the catch pan under the radiator drain fitting on the 300ZX.
Open the drain fitting with a pair of pliers. Allow all of the coolant to drain out into the catch pan.
Move the catch pan under the engine block's drain plug on the front side of the engine. Then, loosen the plug and allow the coolant to drain out from the engine block.
Flush the cooling system with fresh water from a garden hose until the water starts to run clear from both drains.
After you have finished flushing the system, close and tighten both drains.
Inside the Nissan 300ZX, set the heater controls to the highest setting in the cabin.
Loosen the bleeder screw in the inlet housing using a socket wrench.
Add new coolant solution to the radiator (in the filler neck on the radiator where you removed the radiator cap) until coolant leaks out of the bleeder screw and there are no bubbles.
Tighten the bleeder screw once there is bubble-free coolant coming out of the bleeder.
Continue to fill the radiator with coolant until it's full.
Fill the coolant reservoir tank until the coolant level reaches the upper mark.
Turn the engine on and let the 300ZX warm up to normal operating temperature. Leave the radiator cap off. With the temperature inside the cabin set on the warmest setting, let the engine continue to run until the thermostat opens and the coolant solution is running through the system. You'll know when this is happening because the upper radiator hose will become hot to the touch.
Turn the engine off once the coolant is flowing through the system. Let the engine cool down completely.
Return the radiator cap and release the parking brake.
