ive got an 04 blob sti , no problems with the car at all it doesnt leak/use oil or water but when i start it from cold there is a noise like water rushing through pipes which gets louder when i rev the engine is this normal?? and what is it?

 

Normally means there is an airlock in the coolant system.

 

as above, they all do it from the classic onwards.

 

Mine's stopped since I had my head gasket work done. Small airlocks shouldn't cause you too much of an issue, but no airlocks is obviously the preffered choice.

 

mine does this too, whenever I rev the engine i get a gushing water noise, I asumed it was the water running through the heater pipes. So if it's due to an airlock any tips on tracking the problem down and curing it. I've done it before but only on my westfield which was easy as you can see and easily get to all the pipework, I wouldn't know where to start on the scooby.

I have also noticed that it seems impossible to get a warm setting on the heater, it only seems to want to blow hot or very hot, is this due to the air lock too?

 

Not too sure about the heater problem.
With air in the system the easiest way to get it out is caps off the radiator , header tank and expansion bottle. Start the engine with the caps off, let it heat up and you should get a few bubbles in the header tank this will get the air out.