coolant boiling

when i drive my car around and let it warm up and then turn it off i can hear the coolant boiling. i flushed the system and put new coolant into it but that didnt work.
then i did a cylinder leakage test to see if it was the head gasket but they all ranged from 10%-32% leakage. would that cause this problem. if not could anybody give me an idea to what would be the problem

your input will be greatly appreciated

thanks

aparently it's fairly "normal" for the coolant to boil when you shut the engine down. seems sus to me every time i hear it too though...

aparently it's fairly "normal" for the coolant to boil when you shut the engine down. seems sus to me every time i hear it too though...


so wat your saying is that its normal to be able to hear it boil.

I have the same issue, thought it may be the thermostat going.

I have the same issue, thought it may be the thermostat going.


i changed that too but it still does it. but i might have got screwed and got a bad one. do u think i should try changing it again?

your coolant system is pressurized. the pressure raises the boiling point or boiling temp. of the coolant.

therefore if your losing a large amount of pressure from a hole in the radiator or a bad head gasket,
you will lower the boiling point(boiling tempature).

and this will eat up alot of coolant.by evaporation.

What I suggest is get a radiator pressure tester.....hook it up and it should hold atleast 8-12psi ......if its not holding pressure than it will leak quickly as your doing the test, enabling you to find your leak.....

its so easy, even a caveman can do it.

oh yea high leakage percentage from a leak down test could be bad rings, valve seats, oil cap, carbon deposits, head gasket, there are many variables......when your doing the test you should be able to hear the air leak from the problem. ah shit its late.. got2 crash. gl

Hearing your coolant boil in the engine bay is 100% normal for the turbo MR2.

There is nothing to be concerned about.

thanx for all your guys input on the coolant. that definatly makes me feel better. thanx again

-Doug