I have just changed my engine into a newer better gti, it was running fine in my older one but now i can't keep water in it. It keeps boiling up out of the expansion bottle! The temperature gauge reads normal. I have tried bleeding it at all points of the system but still no joy. Next step is to change the water pump, unless someone has any better ideas?? Help.

Thanks for all your help, I have now sorted it!

thermostats are a problem on vr6 and some 2.0