2000 3.0 ohv boiling coolant out

Hi, After installing the new engine and getting it all working, I still have a problem. It is the same problem that caused the engine to have to be changed in the first place. This is a 2000 Taurus Wgn with a 3.0 OHV. It runs great and the temp Gauge reads right in the middle like it should. The problem is that when I turn the engine off after the engine is warm, it will boil the coolant out. Keep in mind that the Gauge doesn't show it being hot at all. When I replaced the engine, I also replaced the radiator as well. I am leaning toward a bad radiator cooling fan (it uses 2 fans) I will be checking it today for just that. It has a new fan switch, and I can hear the fan come on after running for a while. I never looked to see if both were coming on. I will keep up on this post and let everyone know what I find. If anyone knows of a known problem with these vehicles that causes this problem, please let me know. Thank you in advance for any help on this issue. I don't need to put another engine in due to neglect, therefore I want to address this problem ASAP.

Are you saying that the coolant is coming out of the overflow bottle through the cap? Have you replaced that cap? The previous engine problems with high pressure in the cooling system could have ruined the pressure capacity for that cap.

I will have to check that out. I know the bottle is new because it had a crack in the old one. It is not used, it is new.