Coolant overflow

[Pazuzu]

Hi all.

I'm having this recurring problem with my (2-Litre Mark 2 Escort) cooling system. Whenever I take her out for a decent run, I'll stop the car and eventually there will be a whole heap of coolant gushing out of the overflow pipe. This only happens, as far as I can tell, once I've stopped the car & turned the engine off. I end up having to check the water level every single time I drive, and usually the water's disappeared below the level of the radiator fins.

I have tried changing the radiator cap in case there was some problem with the pressure, and it seemed to fix the problem for a month or so (hard to tell, as my car's been on and off the road a lot this year), but now the problem's getting worse.

The hoses and fittings all seem to be fine; the water pump has been making a fair amount of noise, but then it's always made a bit of noise.

Has anyone else here ever heard of this happening? Why would coolant come flowing out of the overflow pipe after engine shutdown? If anyone can help me out with any suggestions, it would be greatly appreciated.

-Dan.