more on my overheating problem.

[roverman]

i had a look at the estima this morning.the expansion tank cap has been ordered(thanks to the rover i can't pick it up)
i decided to refil the cooling system to see how much coolant i had lost,
turns out i only seem to have lost about 1 1/2 litres.
i am hoping this means the headgasket could be o.k.???(unlike the rover that's lost all of it's coolant)
is it a good idea to put the new cap on and give the car a run or am i tempting a worse fate???
'

[owenmall]

I did post on your other thread , if the engine boiled over on a run and you found the seal on the rad cap had failed this is the likely cause of the problem as the pressure raises the boiling point of the water, the system pressurises

to several bar not sure how many but the sudden loss of pressure can force out some water with the escaping pressure and the water may suddenly find it arriving at a lower boiling point. where abouts are you mate as if another member was nearby, you would surely be able to test the theory out for the price of a brew and a chinwag. just swap the cap over whilst you chat and see if the system hoolds water.
So simple case of anybody near roverman with a spare half hour????