ih, my name is XXXXX XXXXX I will help you .
the best thing to do here is pull out the spark plugs nad put a coolant pressure tester on the radiator(install the pressure tester where the radiator cap is ) and pressurize the cooling system ,this will force coolant into the cylinder that is bad or has a crack in it .
now you can see which cylinder is affected.
at this point you will have to remove the head and have it checked at a machine shop for cracks ..it it turns out that there is a crack in the head ,then it has to be fixed or replaced ,if there is no cracks in the head the suspect the block and also check the oil for signs of coolant in the oil as well ....
can the intake manifold cause the problem?