STUMPED on my cooling system

[jessetsi]

The other day I was driving on the freeway and I overheated. A hose from my radiator had busted. So I fixed that, and now there seems to be a huge backup in my cooling system. I changed the thermostat, and everytime I start the car, the hoses expand like there is a lot of pressure in there.

Took the thermostat out to see if that would make any difference, still a bunch of pressure!

Put a new cap on the overflow and it whistles there is so much pressure. Anyone know what is going on?

Can anyone help me?

Thanks!!!

[DeRail]

Was the new cap that you put on the overflow rated for the same pressure as the old one? It is said that if you go to a higher rated cap, you run the risk of causing premature failure in the system.

[billofdurham]

You seem to have an air lock, big style.

Usually when you drain the cooling system you would set the heater control to 'hot' to drain the heater as well as the radiator and the engine. Then when refilling you would leave the control at 'hot' and slowly refill the system to lessen the chances of an air lock. At the same time you should massage the radiator hoses to get all the air out. If the heater control was set at anything but 'hot' you will have an air lock in the heater.

It may pay to drain the system and start again.

I agree with Derail about the cap rating.

Bill.

[skittlejr]

if it is an airlock, this can usually be remedied by removing the cap and running the engine. this should eventually cycle all the air to the expansion tank thus allowing it to all vent. there could be a possibility that there is clog in the radiator core. when you replaced the hose, was the coolant contaminated with oil, rust or any other debris?

[wojeepster]

If the pressue is as soon as you start the car then what probably has happened is that you have blown a head gasket when you overheated the car and this is combustion chamber pressure leaking into the waterjacket.

[skittlejr]

that is exactly right, how hot and for how long did it overheat?