i have been busy working on my landy after the head gasket failed so i have done a strip down of the engine.i have just finished putting the head back on and connected every thing up but i have a very load sucking/blowing noise coming from the engine it sounds abit like a monifold blowing but its not that oh and wen i switch it off .i get the same sucking/blowing noise as she take the last stroke .can anybody pls put in the right direction