i just got a TD05H turbo and the housing of the internal wastegate port is cracked.

will this have any effect on performance of the turbo?

They are all cracked. Just depends how bad it is.

why would it crack? how bad is too bad?

it's got 2 cracks....they're opposite of each other about 3" long each

Those cracks are pretty normal... can you post pics? 3" sounds like a pretty big crack.

yea, in a few hours (still at work). one of them rounds the corner and goes to the Exhaust Manifold mount and the other starts going up towards the turbo

Images of cracked waste-gate housing

Looks fairly run of the mill to me. Just make sure its not too brittle around the crack.

Wastegate crack looks just like mine.

PORT that sucker out.

^^^ Agreed... doesn't look bad at all.

what causes that and will i be able to tell when it gets too bad?

Extreme heat causes it...something a turbo generates normally.
As long as it not cracked all the way through, you'll be fine. I've got 3 housings and they all look like that.

It just caused by heat cycling over time. I wouldn't worry about it getting worse. You'll know when it gets too bad when your turbine housing falls apart.

Seriously though, don't worry about it.