check this pipe ,,,,,,, may be its blocked ,,,,,,,,also check the frost plugs on back side of intake manifold ,,,,, usually they are rusted out and mechanics usually bypass the intake manifold water pipes,,,,,,, i seen this couple of days before on my friend's car ,,,,,, it was also overheating and i noticed there are no pipes connected on intake manifold ,,,,,,, try to find pic for you ,,,,,,,,,,