Hi guys glad I found this forum, really need your help. My gfs 1.4 PUMA turned up at my house the other day in the red and the fan going like mad. I checked the coolant, I must have put about 4 litres in of coolant and water. The day before the car was fine, till she drove in the evening she said that the heating was stuck on hot. I drove the car back to hers, for about 20 minutes after replacing the coolant and the car behaved normally. Could this be the HCV failing? or am I looking at a thermostat issue? I would have thought that the car would have over heated on my 20 minute A road drive if the thermostat was stuck closed? The only reason I am pointing the blame on the HCV is that as soon as the heating was stuck on HOT the engine developed the lack of coolant and over heating. I have checked for leaks and can see none? Many thanks. I'm in my early days of DIY mechanics, But I am confident I can change this valve.

I have thought about a slow leak in the engine, however the overheating came on the next time the car was driven a few days later. The car is driveable, however I am assuming will overheat again in due course.

Cheers again

James