Coolant excessive pressure cold engine

​2000 Ranger 3.0 Flex​ Fuel

Background
Top radiator hose busted and also belt broke off engine coolant all over the place and discovered that the tensioner idler pulley had seized and most
likely caused the belt to brake and coolant got too hot and busted the hose.

Now
I have changed the idler pulley, I also changed the thermostat to make sure because that thing is too old (oem one), I also changed the radiator cap,
filled it up with coolant making sure all of the bubbles were gone.
The Upper radiator hose gets really hot after about 10 minutes of running idling also the cooling hoses for heather that go into the cab get
real hot and the two skinny ones that go into the air manifold get real hot and rock hard.
The bottom Radiator hose stays cold and the hose is easy to squeeze. The radiator cap stays cold.
Also if I run the engine with radiator cap off i see no coolant movement at all.

Today with the engine cold I opened the radiator cap to check the level of coolant in radiator then coolant gushed all over the place and the engine was cold,
it gushed like if it was a hot engine and covered the entire engine bay with coolant, remember it was cald coolant. What can cause this?

I searche all over could find an answer.

 

This reads to me that you are not getting the proper coolant circulation. If the lower hose stays cold but the other hoses are really hot, I'd definitely check the thermostat for proper operation first. Maybe remove thermostat and run engine and see if you get even temps on both lower and upper hose. You'll need to verify you don't have a coolant blockage in the system.

The pressure you have in the system on a cold engine sounds troubling. I'd start the truck with radiator cap open and see if you see bubbles. If you do, it might be wise to check for combustion gases in the cooling system; this would indicate a likely blown head gasket.
Good luck and let us know what ya find!

 

A new thermostat does not mean a good thermostat. Pull thermostat. Open radiator cap and start motor. You should see circulation of coolant immediately. If not, water pump is bad. Easy water pump test. If you do see circulation, then inlstall a new thermostat. Make sure it is installed correctly, not upside down. If that does not fix the problem, you have bigger issues, i.e. blowm head gasket as prrevious post stated.