Re: air coming through cinder block foundation wall
its sounds like convection air movement. it might not neccessarily mean that there is a draft.
putting it simply warm air is escaping through the holes in the block which creates air movement which can simulate a draft
do as mentioned earlier, pick up a few cans of spray foam and fill the voids. and on your next house avoid a block wall foundation. in my region block wall foundations are an absolute nightmare to work on
fire up the saw and make some dust