I posted this problem on the Nabisco site but am having a hard time getting replies.

Please help a novice out. I just bought a used turbo and from the outside it looks fine, claimed to have 750 miles and it looks almost new. Just out of curiosity I blew through the coolant lines, while stopping one up with a finger, to see if it was air tight and they seemed fine. However, while doing the same for the oil inlet and outlet it does not appear tight? I tried the same on my stock turbo. Plugged the hole on top with my finger and tried to blow into the pipe on bottom...impossible. Now I do the same on the VF30 and air is clearly escaping behind the compressor wheel? Am I missing something here? Will this turbo leak oil?

I also noticed that the compressor wheel has carved a groove on the inside wall of the air inlet, is this normal? On the stock I cannot see that the wheel has touched the wall at all?