I had the same issue. First check the coolant system with a pressure pump. I think you can rent it at AutoZone. Second, the smoke could be oil in the intake making it's way to the combustion chamber. Oil is getting sucked in through where that vacuum leak is. The vacuum leak is the diaphragm that acts as a PVC. You should clean the intake manifold out of oil, change the valve cover and check the coolant for leaks.