Tig welding cracked VW 2.0 tdi bkd cylinder head

It is quite likely I'll have a choice in near future whether to replace my cylinder head with a new(used) one or fix it myself. I did tig weld magnesium-aluminium alloys before, but not aluminium-silicone. I read online cylinder heads are often made with aluminium-silicone alloy.
Does anyone know what alloy VW makes their TDI 2.0 heads with? Perhaps someone could test their cylinder head with a metal alloy tester? Unfortunately I don't know anyone who has one. Maybe someone around here tried to weld a VW TDI head and knows which filler rods work?
I already saw this: http://www.weldingtipsandtricks.com/welding-aluminum-cylinder-heads.html It is pretty good info, but not VW specific.

my thoughts

a good welding shop?

Contact frank06.
There are ways of checking what the metal is. Look at youtube channel Cody's Lab on that one.

Mongler98 said:

Contact frank06.
There are ways of checking what the metal is. Look at youtube channel Cody's Lab on that one.

Click to expand...

I looked, but the only video of Cody's Lab regarding identification is about distinguishing aluminium from field's metal. There is no doubt cylinder heads are made of aluminium alloy, not Field's metal. They would turn into liquid if they were Field's metal

Perhaps it wasn't obvious from my previous post, but I have no problem with tig welding aluminium if I know what alloy it is. It would be great if it was possible to find someone knowing what exact alloy VW heads are made from. As far as I know there is no DIY method to distinguish let's say Aluminium with 5% Silicone that welds fine, from Aluminium with 5% Copper that can't be welded at all (but is much stronger and machines better). The only way to find that out is to ask someone who knows or use an expensive metal analyser. I know such devices exist because I got a picture of one's screen that came with a load of lead I was buying some time ago. It showed impurities as low as 0.5%, but the device is not something one buys for hobby use.

I found alloy id when I was looking for the head OEM part number so I'll answer my own question just in case someone in future finds this thread looking for the same info.

The alloy used in 2005 TDI 2.0 16v BKD cylinder head is AlSi7MgCu0.5. That 0.5% of Cu worries me a bit, but hopefully it can be welded fine with a AlSi12 tig filler rod (that's 4047 in US I believe).

It can't hurt to try. If you can't weld it, you need a new head anyway, so you'll be no worse off.

Powodzenia!