Radiator pressure

[Pupp]

Ok, had to replace a freeze plug in my 5.7, also put on n a 4 row (I live in Arizona). Took it for a test drive and all seemed good. Later I saw what looked like a leak at the freeze plug on the passenger side under the motor mount. Got dejected and didn't do anything for a couple weeks. Today I decided to look at it and removed the radiator cap to refill and put some dye in, when I took off the cap, water shot out like it was over heating! Not running and cold! Anyone ever hear of such a thing?

 

[tom3]

Never seen that. To have that pressure cold seems like it would have to have a whole lot of pressure when at operating temperature. Replace cap?

 

[ks03]

Sounds like a bad cap, unless the vent hose is blocked. That being said, since you put in a 4 core you could have an otherwise good cap, and radiator that don’t play well together. I’d look for a listing or try to contact the radiator manufacturer to see if they have a recommended cap for the radiator

 

[OR VietVet]

That also means two things, "it is freakin' possessed" and you have no leaking freeze plug because if you did that pressure would have bled off. I mean, you said it sat for 2 weeks, right. Been in the business a long time and have never ever ever ever seen pressure in a system after 2 weeks and engine cold. When you say, "It shot out" do you mean like a hot engine and went a foot in the air or more or it surprised you and shot out maybe 2"-3"? No one else has keys to the rig?

Like it said, That thing is possessed, period.

 

[Pupp]

That also means two things, "it is freakin' possessed" and you have no leaking freeze plug because if you did that pressure would have bled off. I mean, you said it sat for 2 weeks, right. Been in the business a long time and have never ever ever ever seen pressure in a system after 2 weeks and engine cold. When you say, "It shot out" do you mean like a hot engine and went a foot in the air or more or it surprised you and shot out maybe 2"-3"? No one else has keys to the rig?

Like it said, That thing is possessed, period.

I've never seen anything like it rither. New 4row, cap that came with it, freeze plug was replaced prior. "Shot out" like an over boiling studibaker. No one else touches it. Since then, I topped it off, put dye in it and drove it at temp for 20 or so miles, no problems. Must havr been gremlins. No leaks evident. Thanks for responding.

 

[OR VietVet]

Go ahead, admit it. You called an Exorcist to rid the demons!!!