hi iv just bought a 04 fabia vrs the therostat was being tempramental so i changed it today and having the same problem seem to be when i drive it hard 1 min i will have heaters and everthings fine and next min heaters go cold and starts overheating and thermostat pipe is cold and alot of presher in header water bottle any ideas thanks

You have air in the system mate, couple of tricks are jack it up high and let it gurgel then keep topping up, put a transparent pipe on the bleed nipple and put your chops around the radiator cap and blow until you see bubbles coming out the pipe.

I'm not fully aware of the fabia layout but this works on other cars i've serviced so should on the fabia.

Just run it up from cold until up to temp with the expansion tank cap off. Rev to 2.5k rpm for 30 seconds, and then leave it at idle for 30 seconds and massage top and bottom rad hose during this time. Repeat process until car is up to temp, or water starts boiling over the expansion tank. Turn engine off, leave it to cool down, then top up to correct fill level. Used this method on cars that are notorious for air locks for years, and even though fabs are not, I do it every time now mate.

il try that thanks il let u no how it goes

Has the water pump been changed yet?

How often does the water pump need changed?

same time as the timing belt so around 60,000 miles. Sounded like water pump to me also, but then when your saying the pressure in the cap is signs of an air lock or headgasket failure.

They tend to bleed themselfs you just need to keep an eye on the level for a few days or at least untill its been fully up to temp. Have you felt the heater matrix pipes to see if ones hot and ones cold?

you could just remove the thermostat and drive the car like that for a while to see if it cures the problem, only downside to that is it takes longer for the car to warm up.

Does it help at all on the Fabias to burp the coolant pipes, so to speak ? Ah I guess that is what Sean means by "massaging" lol

Done this recent ish on mind though and have to say it didn't seem to need burping, just lots of stopping and starting and also happened to have the car jacked up both sides to assist with the process of removing any bubbles.

So the advice above is spot on (Sean's) and the key thing is patience.

The reason I did mine I was actually filling and flushing it through though before changing to new coolant on mine, and must say it looks a lot better so worth changing if its over 5 years as that is how long the "lifelong" lasts I think

Thank you for all you feedback bled it all up today didn't seem to need to jack it up thow seem to be fine now thank you