well i took the car for a drive today and at ilde it sounds like a 5cylinder and when i drive it steady it missis and carrys on. then if i get up it it will blow smoke in first gear then seem to clear out and is dosnt blow and after that. but it seem to still be missing. then i flick it on to hi boost and from about 3000rpm and above it seems ok :S i pulled the breather off the rocker cover and its not pressurising its sucking. but theirs old comimg out the bov. could some1 explane to me the symptoms of a
-blown head gasket
-stuffed spark plug
-cracked pistons
-and any other possabilatys