Help! 1999 ford mustang coolant problems

[First-Time-Ford-Owner]

I know this isn't truck related but I own a 1999 Ford mustang 3.8 v6 (please save all v6 mustang jokes aside) just recently it started to over heat not to the point where it was in the red but hot enough where it was spitting coolant out of the resivior and out from the radiator cap. I cooled the car down and it gets back up to temp just fine. The problem is the upper radiator hose won't pressurize or fill with coolant And the hose wants to collapse at operating temp. Any And all ideas or theories would be greatly appreciated!

 

[Plum Ranger XLT]

Check and see if your thermostat is stuck in the closed position. If it is, that's your problem.

 

[RonD]

Spitting coolant out is pretty hot.

Operating temp is 190-200degF
50/50 coolant mix boils at 235degF with no pressure, 265degF with 14psi rad cap pressure.

Ford temp gauge center is about 215degF

Take rad cap off and start cold engine
Make sure coolant is topped off

Turn on heater

let engine idle, feel heater temp as engine idles, it should start to warm up in 2 minutes and be quite warm in 5 minutes.
It not then either water pump is bad or you have air in the heater hose lines.
Feel both heater hoses, could be pump or head gasket

After about 5 minutes thermostat should open and upper hose should start to warm up.
If it isn't warming up after 8-10 minutes thermostat is stuck closed, and you may start seeing coolant being pushed out rad cap opening from pressure in the lower rad hose.

Shut down engine and change thermostat, after it cools down.

If coolant starts to overflow from rad cap before 5 minutes then you have a blown head gasket.

Search for: The glove test
Use TRS search
Free test for cylinder leak

idling engine will never get above 210degF, so no coolant should overflow rad cap.
After upper hose gets hot feel lower hose, it should be about 10degf cooler, so NOT cold, cooler, if it is cold then rad is clogged.

 

[First-Time-Ford-Owner]

I did all that and everything checkout fine. I took it in to the school that I go too (for mechanics) and I had 5 instructors look at it. And they said they noticed stop leak in the coolant and they looked at it more and said that the radiator has a bunch of pinholes in it. And that the radiator is done for and Thats why it did it