Its losing coolant at an extremely low rate, can drive it for 300 miles then the light comes on and only have to top it up slightly.

We have run a pressure test and no sign of losing any pressure. No leaks found at all, from pipes radiator or anywhere. The car has been taken to VW in Ipswich and they cant find a fault, but here is the funny part... they want me to spend £2352 on a new cylinder head because thats the only thing it can be apparently. Instantly, F and Off sprang to mind.

I was hoping someone here might have an idea.

tried a different expansion tank cap? If the cap goes weak and allows air to get by the water can boil and thus will evaporate. Im guessing the pressure test you did was through the expansion bottle which wouldnt show up a dodgy cap. Thats the first thing i would change.

I'm glad Tom said it, If you pressure test it you do it at the cap..........if its burning it, it'll show in the hydrocarbons when you stick the four gas analyzer up it's bum, so by logical conclusion if it doesnt show on the analyzer its the cap.

I had to read that three time, it does make sense doesnt it.

My money would be on the cap too. I am on my third one.

Well, we tried a new cap and it still lost coolant. So I sent the car to Richard at HRD in Ely, he has had it since Monday and confirmed the head is cracked ever so slightly......... Bugger. This is getting more common on the mk5's it seems.
With a new cylinder head priced at £850+ and a lot of labour, I need to find a recon or used head, to try to save as much money as I can.
Thanks for your input though peeps.

850+!! :O

Just got a used Cylinder head for £280 delivered.

Bargain I think, good job I had my striped jumper on and my 'swag' bag with me.

a right result there mate