Cooling problems please HELP

[Mainerz]

Hi drove about 15 miles and heard a hissing from my engine opened the coolant tank and it started spewing out and was very hot could any body tell me why this could. Heaters work fine, fans run, no oil in coolant so the head hasnt gone. Thermostat works fine really scratching my head over this one any help would be great thanks

[jockgti]

temp sensor or water pump?

[Mainerz]

Both running fine dont understand whats going on  just hoping it wont cause any damage at the moment

[xxChrisxx]

Both running fine dont understand whats going on  just hoping it wont cause any damage at the moment

Is it running hot?

It really shouldn't surprise you that hot coolant starts spews out the cooling system when you take the cap off. When things become hot they expand (creating pressure in the system) and will tend to want to move to lower pressure.

In future, feel around the cooling lines in the radiator, is they are both hot you are getting circulation, if one is cold you know that someting is wrong. Much safer than potentially jetting boiling pressurized steam into your hand/face.

[Dalo Harkin]

Hi drove about 15 miles and heard a hissing from my engine opened the coolant tank and it started spewing out and was very hot could any body tell me why this could. Heaters work fine, fans run, no oil in coolant so the head hasnt gone. Thermostat works fine really scratching my head over this one any help would be great thanks

read my last topic I posted 
To check the water pump (with the engine off and cold) unclip the top hose that goes into the coolant expansion tank and unscrew the top cap, place the hose in the tank and then start the engine, you should have a steady stream of coolant going back into the expansion bottle from the hose, if there is then check the other things....

[harlemex]

It could be any number of things making the hissing sound. Might be a snake?

[cullygti]