Hi! First post!

Just bought a rough but reliable favorit estate ('94 vintage). Runs ok, except that is sometime likes to deposit some coolant (or rusty coloured water in this case).

Took it for a 100 mile run and it ran faultlessly, except when I got back and it was idling for a couple of minutes, the coolant started to spurt out the expansion tank. The temperature guage always read normal (but it does seem to work).

I'm no tech but maybe:

-it's just plain old water in there so boils and then spurts out - kept under the boil when driving?

-air bubble in it?

-thermostat?

-head gasket!!! ARGH - no oil in the coolant tho.

-anything else?

crazy wee car, and me and a mate are driving it across europe so want to get the cooling sorted. Any advice gratefully received!

Check whether or not there's a decent anti-freeze in it. These act as "water wetters", so reduce the tendency to boil.

Check the pressure cap on the cooling system, not the thermostat, if it's boiling like this.

I don't think it's the head gasket, cos that usually shows up as steam from the head/block joint IME.

Yeah, my first thought was that it was just water in there, so best get it flushed and changed.

The pressure cap though, well when i took it off it just kind of fell to bits... I guess i thought it was jsut supposed to be like that! THe cap comes off but leaves the spring bit still sitting over the opening... i had to lift that off separately from the cap. Guessing the 2 should come away together?

A new cap perhaps then. Doesn;t sound too expensive

As Ken says, the additive will help increase the boiling point, as will the pressure cap which (when functioning) will keep the coolant under pressure and therefore in the liquid phase. If the cap's had it, the coolant will boil over just like a pan on a stove - no wonder it's sprayed coolant everywhere!

Cheers guys, that was my first thought. Will order a new cap and flush and refill the system.

The rally we're doing across europe is going to work out at about 4000 miles so will keep you all posted on how it goes!

Perhaps we'll need to log-on for advice on the way!!!!

Yeah, my first thought was that it was just water in there, so best get it flushed and changed.

The pressure cap though, well when i took it off it just kind of fell to bits... I guess i thought it was jsut supposed to be like that! THe cap comes off but leaves the spring bit still sitting over the opening... i had to lift that off separately from the cap. Guessing the 2 should come away together?

A new cap perhaps then. Doesn;t sound too expensive

New cap yes; that one's well and truly FUBAR. A new one should only be a few quid.

If it's been like that for any length of time, the coolant flush and refill with a good antifreeze/water mixture is pretty much essential too.