What is this?

[dlittle]

OK, please forgive my ignorance. My 02 4.6l started to smoke about a block from home today, i quickly pulled in and took a look around, there was antifreeze everywhere and I noticed it bubbling up from the port pictured below (just north of the coil in the picture. It sure looks like there is supposed to be a hose attached to that, or is it just a breather port or something? thanks, Dan.

 

[dlittle]

found the cap that is supposed to be there and replaced it, but what would cause such pressure to blow that off?

 

[Joe in NY]

Is your coolant good? Old coolant can loose its ability to not boil under pressure...

 

[pet575]

I would agree that a temp increase (possibly related to decreased circulation?) could cause enough pressure increase to blow that. I've seen hoses pop due to increased pressure as a result of poor circulation when a radiator is clogged up.

 

[dlittle]

Would a bad thermostat cause this? Does anyone know what the part in the picture is? thanks, Dan

 

[pet575]

Honestly I'm very confused on which part you are referring to. "Just a north of" the coil doesn't help me. "North" as in the orientation of the photo? If so, does that mean it came out of the little circular shaped black thing?

 

[dlittle]

sorry, here is another picture with the part in question circled. I guess it is a nipple at the back of the intake manifold. Is it's purpose to be able to flush out the coolant system?

 

[lincolnshibuya]

there's either a plug or a cap on that section of intake manifold. When I replaced my leaking intake manifold with Dorman, it has that optional hole near the #4 plug to connect to a heater hose on some Ford models. The explorer and mountaineer doesn't have that and needs to be plugged. I remember putting them on without plugging that hole and it caused coolant to overflow. I just put in the metal plug and a cap to that hole..

the system is pressurized overtime that cap or plug will get deteriorated and blow off.

 

[pet575]

That is interesting because I replaced my manifold and I don't recall that being there. If it was there, it must have arrived with that plug installed to where I didn't even notice it.

Wonder if the only way to repair that is to replace the manifold?