cadillac overheating still with repairs on 1994 Cadillac Eldorado

A few months ago my car started overheating we changed the thermostat,the radiator (even had it checked for clogs) the water pump, the water pump tensioner and it still overheats at idle when i am driving the temp flucuates between 212 and 221 once it reaxhes 230 driving it will not come back down. It is becoming a headache and all i want is answers there are no leaks and since wee changed the water pump when it overheats it no longer gurgles and spits coolant. WHAT NEXT?

Asked by for the 1994 Cadillac Eldorado
Is the cooling fan coming on at the right temperature? Does the engine cool properly at freeway speeds when "rush air" flowing through the radiator cools the engine and it is no longer dependent on the electric fan. You have done good basic tests and replaced the key "trouble makers". The most accurate way to test for a blown head gasket on a gasoline engine is to test for the presence of carbon monoxide in the cooling system. Snap-On, Matco (part # CO 2000), and Napa sell a tool to check to carry out this test. Another link to a supplier of this tool is Carbon Monoxide is only present if there is a blown head gasket or cracked cylinder head. I think the Napa part number 700-1006. . Signs of a blown head gasket are coolant loss (frequently have to top up the coolant level of the engine without seeing an obvious leak), experiencing over heating or rough engine running or the presence of white sweet smelling steam from the exhaust. A badly blown head gasket may allow engine coolant and oil to mix.
As for coolant loss I suffered coolant loss before we changed the water pump, there wasnt a leak but when it overheated the coolant would bubble up through the coolant tank, is it possible if the coolant cap is not sending in the right pressure would that cause overheating, tomorrow we are going to check the intake manifold gasket and test the thermostat pressure