today iw as out driving my 88 gt around and i looked down and the gauge was pegged at 270. i stoppe dpoped the hood and the overflow was all foam. i added a bunch of water and got it back to my house. there is the small black rubber line coming off the radiator by the cap, where does that go to and what is that for? it had a crack around the nipple and i think thats where i was loosing pressure and causing me to over heat?

 

that hose goes to your overflow tank, maybe where the hose goes on is cracked hose is ripped and your not getting extra coolant from the reservoir to your radiator.

 

that just happend to my dads old 87 honda ......the upped rad hose had a rather big crack in it

 

That was probably causing your issue.I hope you didn't warp a head or anything, that would suck. The coolant doesn't bubble or anything when the car is running and the radiator cap is off does it?

 

it wasnt at 270 for long. at all. i shout it down right away. added waer and it cooled right off. i could hear it hissing from that small hose that goes to the over flow tank. it looks like it was pushing air to the tank and then pumping the coolant out of the resivore.

 

I hope for your sake you don't blow a head gasket, or have warped your heads.

 

if it still foams after the hose is fixed then you may have a head gasket issue

 

After you get it running, check the oil to make sure it isnt contamniated with coolant. Also, if you have acess to an emmisions mission you can put the probe next to the radiator cap, do not suckup any fluid, and check the HC level, if it comes up you may have a blown head gasket. Also, check the obvious, T-sat