Hi all
New Audi owner here and I have been tucked up with an overheating car. Seller has turned phone off and address doesn't actually exist.
I've bought a 2004 a6 avant 2.5l v6 TDI and it was showing symptoms of overheating and poor coolant flow.
I've had it into service position and the water pump had failed. I replaced that and the thermostat whilst I was in there. Overheating problem still exists which isn't good.

Symptoms are white smoke at startup and immense pressure in the header tank. There are no apparent leaks and the heating inside will not get warm. I have tried bleeding any air via the hole on the heater matrix hose but it still doesn't get hot.

I'm assuming now this is the head gasket. I'm willing to do the job myself with the help of my friend who is a competent mechanic. What I want to check first is how prone are the heads to cracking on this model engine and is it worth doing?

As it stands the car is only good for scrap which is what I'd rather not do. Any help or advice will be greatly appreciated.
Thanks