5.9 ZJ Coolant bubbling

[StompJrKz400]

my zj is blubbling coolant out the overflow when the thermostat opens. before that its fine.

i refilled with some water and got it up to temp with the cap off. right around 200ish most of the coolant shot out of the radiator fill hole ( within 15 or so seconds)

i pulled the lower line off the water pump and tryed to look up with a camera and see if maybe the impeller fell off inside or something odd, but i cant get a good view on it.

i have a new waterpump and thermostat on hand, but i want to make sure its that before i tear into it

i removed the belt and the pump spins freely/smooth, no grinding or anything

[StompJrKz400]

ok i pulled the thermostat and retested, took a video to boot

the video is the jeep just getting up to temp, and then it starts gushing, it does it alot more on deceleration for some reason too

http://youtu.be/NS-6GIR-0hs

hoping its not head gasket/ cracked head, but im kinda getting freaked out now.

[Ruepart Hoaxley]

Drain it, start from scratch? Try tapping into the heater hose and running water in from there

[Hudson]

You sure that's not normal?

Without the radiator cap on that thing the cooling system isn't under pressure and it'll boil over a hell of a lot quicker than it will with the 16 pounds the radiator cap is suppose to keep in the system.

If you have a radiator cap on and it's still boiling in your overflow bottle you have pressure coming from somewhere else.

Here's my logic (and don't quote me on any of this because i could be totally full of shit.)

A) There's a hole somewhere in the system. Said hole is letting the pressure that's suppose to be in the cooling system escape causing the water to boil over at a lower temp than it would with pressure in the system.

B) A blown headgasket/cracked head is pushing combustion pressure into the cooling system causing it to bubble.

[92xjlaredo]

You sure that's not normal?

Without the radiator cap on that thing the cooling system isn't under pressure and it'll boil over a hell of a lot quicker than it will with the 16 pounds the radiator cap is suppose to keep in the system.

If you have a radiator cap on and it's still boiling in your overflow bottle you have pressure coming from somewhere else.

Here's my logic (and don't quote me on any of this because i could be totally full of shit.)

A) There's a hole somewhere in the system. Said hole is letting the pressure that's suppose to be in the cooling system escape causing the water to boil over at a lower temp than it would with pressure in the system.

B) A blown headgasket/cracked head is pushing combustion pressure into the cooling system causing it to bubble.

sound logic there.

looking over the hoses to check for holes/pinches or a compression test is necessary.

[StompJrKz400]

Hmm. Doesn't seem to do it with a new radiator cap...

[customcreationsllc]

do you have heat?
If not it is air bound, or you water pump isn't pumping (usually plastic impeller will spin on shaft)

Most cars will not boil over just idling.
Does it have a mechanical fan?

Head gasket will not car if it is hot or not.
Usually will push out under load. Like it will be good one sec then when you power break it it will boil over, well push exhaust gas out.

[armadasx]

im not really sure what your question is here.water boils at roughly 212.....proper operating temp is around 210.thats a very small margin.with a 15/16 psi rad cap it brings your boiling temp up to like 250f. Is the jeep over heating.?is there oil in the antifreeze?

[StompJrKz400]

problem is solved, is was the radiator cap. stuiped