Blowen Head gasket ???? 4AGE

[demis]

Hi

i think my head gasket might be blowen because

the radiator will not pressureise
at idle but when you rev the engine and hold it at about 5000 water starts comming out of the over flow pipe
the (ND) radiator cap seems fine and is only about 6 months old
the top tank is about 3 years old and looks fine
ive tried a cap of my mates car but it does the same thing i dont have a pressure tester to test the cap propperly

i replaced the head gasket 70,000km ago with a toyota one and had the head mechined
the car hasent overheated as far as i know
i cant see any water comming out the exhaust and the oil looks fine

what would be a nother test to do

were can you buy them testers that tell you if there is exhaust gasses in the radiator or not
repco dosent have them

thanks

[evil_si]

it is calley a teekay head check, put in in the radiator cap, run it and if the fluid inside changes colour exhaust gas is present,

repco should have it, other wise you could try an engineers supply type shop, paykels / blackwoods. bay engineers supplies

[demis]

ok
after testing it again today
i dont think the head gasket is blowen

but there is still two things i cant work out
one
it used some water
but after 50 km of driving today givving it death it dident use any

two
the radiator dosent seem to be pressurising properally
you can remove the cap when the car is at operating temp and there is almost no pressure should there be heaps or pressure???

i noticed while holding the engine at 4000 rpm
the overflow bottle began to full up then the fans turned on and it whent back down to the same point i let it do this 3 times in a row and the water returned to the same level both times

i think im making problems that dont exist

i will probally go and get it pressure tested when the garages are open again
and change the coolent

[CozmoNz]

ok
after testing it again today
i dont think the head gasket is blowen

but there is still two things i cant work out
one
it used some water
but after 50 km of driving today givving it death it dident use any

two
the radiator dosent seem to be pressurising properally
you can remove the cap when the car is at operating temp and there is almost no pressure should there be heaps or pressure???

i noticed while holding the engine at 4000 rpm
the overflow bottle began to full up then the fans turned on and it whent back down to the same point i let it do this 3 times in a row and the water returned to the same level both times

i think im making problems that dont exist

i will probally go and get it pressure tested when the garages are open again
and change the coolent

ok, it will only pressureize when there is no where for the excess heat to go, eg, once it heats ALL the water up, it will start to pressureize it, maybe it was somewhere to escape to?

when you did it was your heater on hot? is your heater core leaking? when you were giving it shit was the heater on hot or cold? put the cap on, set the heater to cold rev to say 3-4, get the car nice and warm, then check for pressure, do the same on hot heater setting, any difference? get it taken to a mechanic and have the propper tester done.

you say after testing it again today, does that mean you never did use the real tester? my suggestion is to use that .

[demis]

no i dont have a tester

but with the car warmed up

there is no pressure

tried it with the heater on and off

ive had a good look at all the piping and heater
cant see any leaks plus it dosent seem to be using any water

the cap will let water past for a while befor the fans turn on then it stopps and starts to draw it back
so i dont see how it could rearly be a leak because it would all just flow out through the leak

i thought that there should be pressure when the car was at operating temp

[CozmoNz]

no i dont have a tester

but with the car warmed up

there is no pressure

tried it with the heater on and off

ive had a good look at all the piping and heater
cant see any leaks plus it dosent seem to be using any water

the cap will let water past for a while befor the fans turn on then it stopps and starts to draw it back
so i dont see how it could rearly be a leak because it would all just flow out through the leak

i thought that there should be pressure when the car was at operating temp

Mate of mine has a blown headgasket (vickrin), but will ONLY flow out when theres is pressure forcing it out.

eg, if you have a cup, filled with water, why would it go out the top? (the heater is a high point in the cooling system), if you put pressure into the cup, it will be forced out (take alot of pressure to force water from a cup, without boiling it, but my point is, without pressure, it has no reason to leave).

[demis]

So what you are saying is it could be the heater leaking ?????



what i dont understand is how the cap is letting watter out to the over flow bottol when the engine is held at 4000, but then there is no pressure in the radiator at idle
ive tried 3 caps and the top tank looks good

2 work fine on other cars


i think i need a presure tester