Recently I been hearing a strange noise almost like swishing or gargling water when I lightly rev the car? It seems to happen more oftem when the engine is cold. Any idea's?

It goes away when the car is warm but only has happened to me once.

Does anybody know?

 

Your post seems a little contradictory. You say the gargling happens more often when the car is cold. Then you say the sound went away once when after the engine warmed up.

I'm assuming you are driving a more or less stock impreza. Is your coolant reservoir dry (coolant level is below the fill hose) when the car is cold? Any coolant leaks?

 

Air bubbles in teh coolant system

 

When I started my car up at my brothers house the car was cold and there was this gargling sound that I could hear from the inside of the car. When I rev it a little the gargling sound was louder. I waited for the car to warm up a little bit more then I drove home. And there was no sound. I was just wondering if this is just normal and the car was just cold.

 

It's not normal for the car to do this either cold or warm. The first thing I'd check is the cooling system.

 

Its not normal...your coolant reservoir is empty. This is OK if you just had maintenance done, but if you havn't then you have a coolant leak.