Coolant over flowing

[blageo23]

Everytime I drive my car and it gets hot the coolant overflows out of the overflow bottle. For and overflow I have a greddy catch can and the nipple that goes to the water neck has another hose on the other side in the catch can to "suck up" coolant. When I stop the car the coolant in the overflow is boiling like theres no tomorrow. Could I have a bad cap that does not hold pressure and releases to much coolant?

[Shane55113]

Most likely you got it, replace it and let us know.

[AJ]

Yeah, sounds like it's the cap. Question is how long have you driven it while it's been boiling over hot?

[blageo23]

Ive driven it like 3 times when thats happend. Each time I fill it up before I go the next time. Its been broken so I havent driven it much. Thanks guys Ill go buy a new one.

[JET]

Could be a popped head gasket too.

[blageo23]

I have a metal head gasket

[AJ]

I'd drain all the coolant and oil and see if there's any mixing of the to. If there is you at very least gonna need a new HG. From there the head could be warped. And draining the fluids is a cheap way to find out wtf is wrong, if anything.

[Kracka]

Any white milky substance on the bottom of your oil cap? Any brown swirls in your coolant?

[blageo23]

I just changed the oil like 100 miles ago and there was nothing odd about it. The coolant in the overflow is green. And the head was rebuilt(and surfaced was smoothed and stuff) last year and probably has about 600 miles on it.

[carltalon]

You could do what I did this weekend and run the hose out through the hood and watch when the coolant blows out. Mine blows like crazzy under boost so Im assuming its a head gasket.