hi .daughter has 10 plate fiesta 1.4 zetec.dont see the car that much.so a couple of weeks back checked the coolant and i was surprised how much it needed to top up.left it for about 5 days and when checked again needed topping up again.couldnt see any visible coolant leak.so left it for a few days again and this time no topping up needed.since then it seems ok now.but has any body else come across coolant loss issue but then seems to right itself.thank you for any advice.rob.

If you lose too much coolant and forget to check it can cause a airlock But if you put the right antifreeze back in again and keep top it out slowly  While the engine is running as you did it will then clear also worth checking other parts around the engine for any signs of cooling loss specially sensors and  hose clip it might be worth adding a stop leak to the water some time works, 

thanks for that tellme 50.much appreciated.

Depends if she had used the car between checks, or had it just stood?