Being a similar engine to my old VS.
To completely drain the block you have to remove the knock sensors from the engine itself.
When you drop the bottom hose offa the radiator, you only get bout half of what sould come out. :b:
I just ended up paying my mechanic to do it on my VX.
Only cost $100 including new coolant.
Just make sure if you do it, that you bleed the coolant system when your done! Dont want no air bubbles in there!