Anything and everything GT6.

Hi

Well I spent Saturday flushing & back flushing everything and it looks like I'm getting nice clean water flowing through the system apart from the engine block drain plug. I know this probably sounds like a daft question but I'm assuming that if you remove the plug you'd expect coolant to run out? There's nothing coming out of mine! Now I'm assuming that this suggests a blockage in the engine block. If so how do I go about clearing it? I've poked about with a bit of wire & nothing seems to be happening.

Thanks in advance for your help

David