hey every time i go for a drive and come bak home water pisses out the overflow. i think there is heaps ov air in there.. how do i stop it. i have to fill it up everytime i go for a drive

Thermostat okay? Radiator blocked?

If the temperature is ok, replace the coolant tank cap. It may be over-pressurising the system. This is usually the first place to start because they fail often, are cheap and easy to change. Be sure to bleed the system of air after you refill it too:

Start the car with the cap removed, turn the heater on to 32C.

Wait for the car to heat up to its normal operating temperature.

Keep an eye on the level and if it drops, top it up.

At the end the car should be at temperature and full of coolant.

Then put your new cap on and go for a spin, see what happens.

If its running too hot, you have other problems like what Vic suggested. Could be:

-Thermostat (Does the heater work?)
-Radiator
-Thermo Fans-Can you see them both going when the car is hot with the AC on? Should be able to hear them and feel the hot air too.
-Water Pump

Remember to use a decent coolant concentrate too. The Alloy Timing cover on a 5.0 will corrode away if you just use tap water.