A few weeks ago the AST fitting on the lower rad end tank cracked off. Luckily I spotted this before I drove anywhere. I took the opportunity to throw out the stock rad and throw in a PWR 42mm radiator.

This was a week ago. Ever since then my cooling system has me VERY worried:

1) It holds pressure overnight - 14hours after being shut-off, there is still heaps of pressure in the system!

2) It's STILL taking water. I know it takes a week to bleed the system properly but I've now got about 9 or 10 litres of coolant in the damn thing.

3) The overflow on the overflow tank looks wet as if the water is coming out of there. I never catch it in the act though

All I can think of is that there is a bad water seal that pressurizes the system but won't let water leak past it when the car is shut off. Sort of like a one-way valve. But this doesn't explain:

a) I can bring the car up to operating temp and still see no bubbles @ the filler neck
b) There is absolutely NO smoke at startup. I mean none whatsoever. Surely a bit of water would get past before the engine cools?
c) There's none of that white crud build-up (yet) that would tell me there's oil in the system.


Has anyone seen anything like this before? It's taken me 18 months to get my new engine right, so I'd be pretty pissed off if I've lost another one

-pete

 

check the hoses that connects to the overflow container. It seems strange that it would hold pressure and still be leaking.

 

try taking out the spark plugs to look for any signs of coolant on the tips after pressurizing the system for an hour. also try disconnecting the EGI fuse and cranking it without the spark plugs and seeing if any water or steam comes out. have someone crank it while you look w/ a flash light.

 

Sounds to me like all the air is not purged out of the system.

 

just posting a follow up since I hate it when other people don't :

My motor has now decided to stop disobeying the laws of thermodynamics. It doesn't hold pressure over night and in fact cools and draws in water from the overflow. It now no longer takes water. So to totally bleed the engine took just over two weeks of sollid driving and around 11 litres of coolant all up (overflow included). Thank god it's over! Still can crack 90degrees C on a hot day here. Just need a 3 or 4 -plate clutch, new front discs and I'm off to the track to do some real PWR FMIC / PWR RAD testing

-pete

 

Check this thread