N.M.
What does he smell like? You said BO - like sweaty sports or like old food.
Do you breast feed - are you eating garlic or other smelly foods?
Is his dad sneaking his old socks into the crib to make you crazy? (couldn't resist the joke)
This is odd - I would keep him warm and look at what he is eating. If it is a formula - you may want to switch to an organic formula without chemicals.
Look for chemicals in his environment that he could be reacting to.